Addressed checkstyle issue

.github/FUNDING.yml

@@ -1 +0,0 @@
-github: [iluwatar]

.gitignore

@@ -16,4 +16,5 @@ datanucleus.log
 /bin/
 /bin/
 *.log
+data-mapper/src/main/resources/log4j.xml
 event-sourcing/Journal.json

.travis.yml

@@ -1,29 +1,30 @@
 language: java
-dist: bionic
 jdk:
-- openjdk11
-sudo: required
+- oraclejdk8
 
 env:
   global:
-  - secure: "DCpazS3nkLnter3sguXEAS2fC/1ZWNfM+XLyif9MfNFxlZdpni2vCD/jA0Rdpga8puQWHNVLyAec+RPFH/2qSmJ1c1UTV5MaLv8tPqwUX0VFA+1I6XoSv6oX4ldHTBWHEWqQHkRFOLoil0h0edc0tTOWQwXF8U+DLAB+HkRb4gw="
+  - GH_REF: github.com/iluwatar/java-design-patterns.git
+  - secure: LxTDuNS/rBWIvKkaEqr79ImZAe48mCdoYCF41coxNXgNoippo4GIBArknqtv+XvdkiuRZ1yGyj6pn8GU33c/yn+krddTUkVCwTbVatbalW5jhQjDbHYym/JcxaK9ZS/3JTeGcWrBgiPqHEEDhCf26vPZsXoMSeVCEORVKTp1BSg=
+  - secure: "eoWlW9GyTJY04P8K3pxayXwU9/hmptQg/LfirispQkV9YvmziCfSzXnatnBhNfud98sCzY8BScXnb+OWLTnjLKpId4rtEqb0aJ40Jc32cUKzgzFAUn7cNcDAbUIfyPAGVqyQqfj/11wYSADwWMMOPlW97ExUtoyiH2WenXuRHso="
+  
+before_install:
+- export DISPLAY=:99.0
+- sh -e /etc/init.d/xvfb start
 
-services:
-- xvfb
-
-addons:
-  sonarcloud:
-    organization: "iluwatar"
-    token:
-      secure: "FpHwMYPMkdWU6CeIB7+O3qIeIM4vJMp47UjkKK53f0w0s6tPZofZZkab+gcL2TqKSil7sFVB/AQXU1cUubflRszwcLbNsc8H2yFehD79o0o0Mqd1Dd5ip/q0KQbHkkln+InFlVLfvrLB4Xd4mlQVxbGhqpULBhXjKzFzQlRFcuU="
-script:
-  # Because of Travis security restrictions, SonarCloud analysis cannot be run on pull requests originated from forks
-  # See https://docs.travis-ci.com/user/pull-requests/#pull-requests-and-security-restrictions
-  - 'if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then mvn clean verify; fi'
-  - 'if [ "$TRAVIS_PULL_REQUEST" = "false" ]; then mvn clean verify sonar:sonar -Dsonar.projectKey=iluwatar_java-design-patterns -Dsonar.host.url=https://sonarcloud.io; fi'
+# default install command is just "mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V"
+install:
+- mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V -e
 
 after_success:
-- bash update-website.sh
+- mvn clean org.jacoco:jacoco-maven-plugin:prepare-agent package sonar:sonar -Dsonar.host.url=https://sonarcloud.io -Dsonar.login=$SONAR_TOKEN
+- bash update-ghpages.sh
+
+# use latest java version available instead of travis default
+addons:
+  apt:
+    packages:
+      - oracle-java8-installer
 
 notifications:
   email:
@@ -34,3 +35,5 @@ notifications:
     on_success: change  # options: [always|never|change] default: always
     on_failure: always  # options: [always|never|change] default: always
     on_start: never     # options: [always|never|change] default: always
+
+sudo: required

CODE_COVERAGE.md

@@ -0,0 +1,13 @@
+# Code Coverage Report generation
+
+To generate the code coverage report, execute the following command:
+> mvn clean verify jacoco:report
+
+This will generate code coverage report in each of the modules. In order to view the same, open the following file in your browser.
+> target/site/jacoco/index.html 
+
+Please note that the above folder is created under each of the modules. For example:
+* adapter/target/site/jacoco/index.html 
+* busniess-delegate/target/site/jacoco/index.html 
+
+

README.md

@@ -7,31 +7,24 @@
 [![Build status](https://travis-ci.org/iluwatar/java-design-patterns.svg?branch=master)](https://travis-ci.org/iluwatar/java-design-patterns)
 [![License MIT](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/iluwatar/java-design-patterns/master/LICENSE.md)
 [![Join the chat at https://gitter.im/iluwatar/java-design-patterns](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![Sonarcloud Status](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=alert_status)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns) 
+[![Quality Gate](https://sonarcloud.io/api/project_badges/measure?project=com.iluwatar%3Ajava-design-patterns&metric=alert_status)](https://sonarcloud.io/dashboard/index/com.iluwatar%3Ajava-design-patterns)
 
 # Introduction
 
-Design patterns are the best formalized practices a programmer can use to
+Design patterns are formalized best practices that the programmer can use to
 solve common problems when designing an application or system.
 
 Design patterns can speed up the development process by providing tested, proven
 development paradigms.
 
-Reusing design patterns help prevent subtle issues that cause major
+Reusing design patterns helps to prevent subtle issues that can cause major
 problems, and it also improves code readability for coders and architects who
 are familiar with the patterns.
 
 # Getting started
 
-This site showcases Java Design Patterns. The solutions have been developed by
-experienced programmers and architects from the open source community. The 
-patterns can be browsed by their high level descriptions or by looking at their
-source code. The source code examples are well commented and can be thought as
-programming tutorials how to implement a specific pattern. We use the most
-popular battle-proven open source Java technologies.
-
 Before you dive into the material, you should be familiar with various
-software design principles.
+Programming/Software Design Principles.
 
 All designs should be as simple as possible. You should start with KISS, YAGNI,
 and Do The Simplest Thing That Could Possibly Work principles. Complexity and
@@ -42,17 +35,12 @@ Once you are familiar with these concepts you can start drilling down into
 patterns by any of the following approaches
 
  - Using difficulty tags, `Difficulty-Beginner`, `Difficulty-Intermediate` & `Difficulty-Expert`.
- - Using pattern categories, `Creational`, `Behavioral`, and others.
+ - Using pattern categories, `Creational`, `Behavioral` and others.
  - Search for a specific pattern. Can't find one? Please report a new pattern [here](https://github.com/iluwatar/java-design-patterns/issues).
 
-Hopefully you find the object oriented solutions presented on this site useful
-in your architectures and have as much fun learning them as we had developing them.
-
 # How to contribute
 
-If you are willing to contribute to the project you will find the relevant information in 
-our [developer wiki](https://github.com/iluwatar/java-design-patterns/wiki). We will help 
-you and answer your questions in the [Gitter chatroom](https://gitter.im/iluwatar/java-design-patterns).
+If you are willing to contribute to the project you will find the relevant information in our [developer wiki](https://github.com/iluwatar/java-design-patterns/wiki). We will help you and answer your questions in the [Gitter chatroom](https://gitter.im/iluwatar/java-design-patterns).
 
 # License
 

abstract-document/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,14 +29,19 @@
     <parent>
         <artifactId>java-design-patterns</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
+        <version>1.21.0-SNAPSHOT</version>
     </parent>
     <artifactId>abstract-document</artifactId>
     <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
             <scope>test</scope>
         </dependency>
     </dependencies>
-</project>
+</project>

abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,18 +20,17 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument;
 
-import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Function;
 import java.util.stream.Stream;
 
 /**
- * Abstract implementation of Document interface.
+ * Abstract implementation of Document interface
  */
 public abstract class AbstractDocument implements Document {
 
@@ -55,21 +54,17 @@ public abstract class AbstractDocument implements Document {
 
   @Override
   public <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor) {
-    return Stream.ofNullable(get(key))
-        .filter(Objects::nonNull)
-        .map(el -> (List<Map<String, Object>>) el)
-        .findAny()
-        .stream()
-        .flatMap(Collection::stream)
-        .map(constructor);
+    Optional<List<Map<String, Object>>> any = Stream.of(get(key)).filter(el -> el != null)
+        .map(el -> (List<Map<String, Object>>) el).findAny();
+    return any.isPresent() ? any.get().stream().map(constructor) : Stream.empty();
   }
 
   @Override
   public String toString() {
-    var builder = new StringBuilder();
+    StringBuilder builder = new StringBuilder();
     builder.append(getClass().getName()).append("[");
-    properties.forEach((key, value) -> builder.append("[").append(key).append(" : ").append(value)
-        .append("]"));
+    properties.entrySet()
+        .forEach(e -> builder.append("[").append(e.getKey()).append(" : ").append(e.getValue()).append("]"));
     builder.append("]");
     return builder.toString();
   }

abstract-document/src/main/java/com/iluwatar/abstractdocument/App.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,64 +20,67 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument;
 
 import com.iluwatar.abstractdocument.domain.Car;
-import com.iluwatar.abstractdocument.domain.enums.Property;
-import java.util.List;
-import java.util.Map;
+import com.iluwatar.abstractdocument.domain.HasModel;
+import com.iluwatar.abstractdocument.domain.HasParts;
+import com.iluwatar.abstractdocument.domain.HasPrice;
+import com.iluwatar.abstractdocument.domain.HasType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
 /**
- * The Abstract Document pattern enables handling additional, non-static properties. This pattern
- * uses concept of traits to enable type safety and separate properties of different classes into
- * set of interfaces.
- *
- * <p>In Abstract Document pattern,({@link AbstractDocument}) fully implements {@link Document})
- * interface. Traits are then defined to enable access to properties in usual, static way.
+ * The Abstract Document pattern enables handling additional, non-static
+ * properties. This pattern uses concept of traits to enable type safety and
+ * separate properties of different classes into set of interfaces.
+ * <p>
+ * <p>
+ * In Abstract Document pattern,({@link AbstractDocument}) fully implements
+ * {@link Document}) interface. Traits are then defined to enable access to
+ * properties in usual, static way.
  */
 public class App {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
   /**
-   * Executes the App.
+   * Executes the App
    */
   public App() {
     LOGGER.info("Constructing parts and car");
 
-    var wheelProperties = Map.of(
-        Property.TYPE.toString(), "wheel",
-        Property.MODEL.toString(), "15C",
-        Property.PRICE.toString(), 100L);
+    Map<String, Object> carProperties = new HashMap<>();
+    carProperties.put(HasModel.PROPERTY, "300SL");
+    carProperties.put(HasPrice.PROPERTY, 10000L);
 
-    var doorProperties = Map.of(
-        Property.TYPE.toString(), "door",
-        Property.MODEL.toString(), "Lambo",
-        Property.PRICE.toString(), 300L);
+    Map<String, Object> wheelProperties = new HashMap<>();
+    wheelProperties.put(HasType.PROPERTY, "wheel");
+    wheelProperties.put(HasModel.PROPERTY, "15C");
+    wheelProperties.put(HasPrice.PROPERTY, 100L);
 
-    var carProperties = Map.of(
-        Property.MODEL.toString(), "300SL",
-        Property.PRICE.toString(), 10000L,
-        Property.PARTS.toString(), List.of(wheelProperties, doorProperties));
+    Map<String, Object> doorProperties = new HashMap<>();
+    doorProperties.put(HasType.PROPERTY, "door");
+    doorProperties.put(HasModel.PROPERTY, "Lambo");
+    doorProperties.put(HasPrice.PROPERTY, 300L);
 
-    var car = new Car(carProperties);
+    carProperties.put(HasParts.PROPERTY, Arrays.asList(wheelProperties, doorProperties));
+
+    Car car = new Car(carProperties);
 
     LOGGER.info("Here is our car:");
-    LOGGER.info("-> model: {}", car.getModel().orElseThrow());
-    LOGGER.info("-> price: {}", car.getPrice().orElseThrow());
+    LOGGER.info("-> model: {}", car.getModel().get());
+    LOGGER.info("-> price: {}", car.getPrice().get());
     LOGGER.info("-> parts: ");
-    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}",
-        p.getType().orElse(null),
-        p.getModel().orElse(null),
-        p.getPrice().orElse(null))
-    );
+    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}", p.getType().get(), p.getModel().get(), p.getPrice().get()));
   }
 
   /**
-   * Program entry point.
+   * Program entry point
    *
    * @param args command line args
    */

abstract-document/src/main/java/com/iluwatar/abstractdocument/Document.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument;
 
 import java.util.Map;
@@ -28,12 +27,12 @@ import java.util.function.Function;
 import java.util.stream.Stream;
 
 /**
- * Document interface.
+ * Document interface
  */
 public interface Document {
 
   /**
-   * Puts the value related to the key.
+   * Puts the value related to the key
    *
    * @param key   element key
    * @param value element value
@@ -42,7 +41,7 @@ public interface Document {
   Void put(String key, Object value);
 
   /**
-   * Gets the value for the key.
+   * Gets the value for the key
    *
    * @param key element key
    * @return value or null
@@ -50,7 +49,7 @@ public interface Document {
   Object get(String key);
 
   /**
-   * Gets the stream of child documents.
+   * Gets the stream of child documents
    *
    * @param key         element key
    * @param constructor constructor of child class

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Car.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,14 +20,14 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument.domain;
 
-import com.iluwatar.abstractdocument.AbstractDocument;
 import java.util.Map;
 
+import com.iluwatar.abstractdocument.AbstractDocument;
+
 /**
- * Car entity.
+ * Car entity
  */
 public class Car extends AbstractDocument implements HasModel, HasPrice, HasParts {
 

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasModel.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,20 +20,21 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument.domain;
 
-import com.iluwatar.abstractdocument.Document;
-import com.iluwatar.abstractdocument.domain.enums.Property;
 import java.util.Optional;
 
+import com.iluwatar.abstractdocument.Document;
+
 /**
- * HasModel trait for static access to 'model' property.
+ * HasModel trait for static access to 'model' property
  */
 public interface HasModel extends Document {
 
+  String PROPERTY = "model";
+
   default Optional<String> getModel() {
-    return Optional.ofNullable((String) get(Property.MODEL.toString()));
+    return Optional.ofNullable((String) get(PROPERTY));
   }
 
 }

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasParts.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,21 +20,21 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument.domain;
 
-import com.iluwatar.abstractdocument.Document;
-import com.iluwatar.abstractdocument.domain.enums.Property;
 import java.util.stream.Stream;
 
+import com.iluwatar.abstractdocument.Document;
+
 /**
- * HasParts trait for static access to 'parts' property.
+ * HasParts trait for static access to 'parts' property
  */
 public interface HasParts extends Document {
 
+  String PROPERTY = "parts";
 
   default Stream<Part> getParts() {
-    return children(Property.PARTS.toString(), Part::new);
+    return children(PROPERTY, Part::new);
   }
 
 }

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasPrice.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,21 +20,21 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument.domain;
 
-import com.iluwatar.abstractdocument.Document;
-import com.iluwatar.abstractdocument.domain.enums.Property;
 import java.util.Optional;
 
+import com.iluwatar.abstractdocument.Document;
+
 /**
- * HasPrice trait for static access to 'price' property.
+ * HasPrice trait for static access to 'price' property
  */
 public interface HasPrice extends Document {
 
+  String PROPERTY = "price";
 
   default Optional<Number> getPrice() {
-    return Optional.ofNullable((Number) get(Property.PRICE.toString()));
+    return Optional.ofNullable((Number) get(PROPERTY));
   }
 
 }

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasType.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,21 +20,21 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument.domain;
 
 import com.iluwatar.abstractdocument.Document;
-import com.iluwatar.abstractdocument.domain.enums.Property;
+
 import java.util.Optional;
 
 /**
- * HasType trait for static access to 'type' property.
+ * HasType trait for static access to 'type' property
  */
 public interface HasType extends Document {
 
+  String PROPERTY = "type";
 
   default Optional<String> getType() {
-    return Optional.ofNullable((String) get(Property.TYPE.toString()));
+    return Optional.ofNullable((String) get(PROPERTY));
   }
 
 }

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Part.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,14 +20,14 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument.domain;
 
-import com.iluwatar.abstractdocument.AbstractDocument;
 import java.util.Map;
 
+import com.iluwatar.abstractdocument.AbstractDocument;
+
 /**
- * Part entity.
+ * Part entity
  */
 public class Part extends AbstractDocument implements HasType, HasModel, HasPrice {
 

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/enums/Property.java

@@ -1,32 +0,0 @@
-/*
- * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-package com.iluwatar.abstractdocument.domain.enums;
-
-/**
- * Enum To Describe Property type.
- */
-public enum Property {
-
-  PARTS, TYPE, PRICE, MODEL
-}

abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,18 +20,20 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument;
 
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Stream;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import org.junit.jupiter.api.Test;
-
 /**
  * AbstractDocument test class
  */
@@ -57,26 +59,29 @@ public class AbstractDocumentTest {
 
   @Test
   public void shouldRetrieveChildren() {
-    var children = List.of(Map.of(), Map.of());
+    Map<String, Object> child1 = new HashMap<>();
+    Map<String, Object> child2 = new HashMap<>();
+    List<Map<String, Object>> children = Arrays.asList(child1, child2);
 
     document.put(KEY, children);
 
-    var childrenStream = document.children(KEY, DocumentImplementation::new);
+    Stream<DocumentImplementation> childrenStream = document.children(KEY, DocumentImplementation::new);
     assertNotNull(children);
     assertEquals(2, childrenStream.count());
   }
 
   @Test
   public void shouldRetrieveEmptyStreamForNonExistingChildren() {
-    var children = document.children(KEY, DocumentImplementation::new);
+    Stream<DocumentImplementation> children = document.children(KEY, DocumentImplementation::new);
     assertNotNull(children);
     assertEquals(0, children.count());
   }
 
   @Test
   public void shouldIncludePropsInToString() {
-    var props = Map.of(KEY, (Object) VALUE);
-    var document = new DocumentImplementation(props);
+    Map<String, Object> props = new HashMap<>();
+    props.put(KEY, VALUE);
+    DocumentImplementation document = new DocumentImplementation(props);
     assertTrue(document.toString().contains(KEY));
     assertTrue(document.toString().contains(VALUE));
   }

abstract-document/src/test/java/com/iluwatar/abstractdocument/AppTest.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument;
 
 import org.junit.jupiter.api.Test;

abstract-document/src/test/java/com/iluwatar/abstractdocument/DomainTest.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,18 +20,22 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractdocument;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import com.iluwatar.abstractdocument.domain.Car;
+import com.iluwatar.abstractdocument.domain.HasModel;
+import com.iluwatar.abstractdocument.domain.HasParts;
+import com.iluwatar.abstractdocument.domain.HasPrice;
+import com.iluwatar.abstractdocument.domain.HasType;
 import com.iluwatar.abstractdocument.domain.Part;
-import com.iluwatar.abstractdocument.domain.enums.Property;
-import java.util.List;
-import java.util.Map;
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  * Test for Part and Car
  */
@@ -46,27 +50,27 @@ public class DomainTest {
 
   @Test
   public void shouldConstructPart() {
-    var partProperties = Map.of(
-        Property.TYPE.toString(), TEST_PART_TYPE,
-        Property.MODEL.toString(), TEST_PART_MODEL,
-        Property.PRICE.toString(), (Object) TEST_PART_PRICE
-    );
-    var part = new Part(partProperties);
-    assertEquals(TEST_PART_TYPE, part.getType().orElseThrow());
-    assertEquals(TEST_PART_MODEL, part.getModel().orElseThrow());
-    assertEquals(TEST_PART_PRICE, part.getPrice().orElseThrow());
+    Map<String, Object> partProperties = new HashMap<>();
+    partProperties.put(HasType.PROPERTY, TEST_PART_TYPE);
+    partProperties.put(HasModel.PROPERTY, TEST_PART_MODEL);
+    partProperties.put(HasPrice.PROPERTY, TEST_PART_PRICE);
+    Part part = new Part(partProperties);
+
+    assertEquals(TEST_PART_TYPE, part.getType().get());
+    assertEquals(TEST_PART_MODEL, part.getModel().get());
+    assertEquals(TEST_PART_PRICE, part.getPrice().get());
   }
 
   @Test
   public void shouldConstructCar() {
-    var carProperties = Map.of(
-        Property.MODEL.toString(), TEST_CAR_MODEL,
-        Property.PRICE.toString(), TEST_CAR_PRICE,
-        Property.PARTS.toString(), List.of(Map.of(), Map.of())
-    );
-    var car = new Car(carProperties);
-    assertEquals(TEST_CAR_MODEL, car.getModel().orElseThrow());
-    assertEquals(TEST_CAR_PRICE, car.getPrice().orElseThrow());
+    Map<String, Object> carProperties = new HashMap<>();
+    carProperties.put(HasModel.PROPERTY, TEST_CAR_MODEL);
+    carProperties.put(HasPrice.PROPERTY, TEST_CAR_PRICE);
+    carProperties.put(HasParts.PROPERTY, Arrays.asList(new HashMap<>(), new HashMap<>()));
+    Car car = new Car(carProperties);
+
+    assertEquals(TEST_CAR_MODEL, car.getModel().get());
+    assertEquals(TEST_CAR_PRICE, car.getPrice().get());
     assertEquals(2, car.getParts().count());
   }
 

abstract-factory/README.md

@@ -109,10 +109,10 @@ public class OrcKingdomFactory implements KingdomFactory {
 Now we have our abstract factory that lets us make family of related objects i.e. Elven kingdom factory creates Elven castle, king and army etc.
 
 ```java
-var factory = new ElfKingdomFactory();
-var castle = factory.createCastle();
-var king = factory.createKing();
-var army = factory.createArmy();
+KingdomFactory factory = new ElfKingdomFactory();
+Castle castle = factory.createCastle();
+King king = factory.createKing();
+Army army = factory.createArmy();
 
 castle.getDescription();  // Output: This is the Elven castle!
 king.getDescription(); // Output: This is the Elven king!
@@ -143,7 +143,7 @@ public static class FactoryMaker {
 }
 
 public static void main(String[] args) {
-  var app = new App();
+  App app = new App();
 
   LOGGER.info("Elf Kingdom");
   app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));
@@ -169,25 +169,24 @@ Use the Abstract Factory pattern when
 *	you need a run-time value to construct a particular dependency
 *	you want to decide which product to call from a family at runtime.
 *	you need to supply one or more parameters only known at run-time before you can resolve a dependency.
-* when you need consistency among products
-* you don’t want to change existing code when adding new products or families of products to the program.
 
 ## Use Cases:	
 
 *	Selecting to call the appropriate implementation of FileSystemAcmeService or DatabaseAcmeService or NetworkAcmeService at runtime.
 *	Unit test case writing becomes much easier
-* UI tools for different OS
 
 ## Consequences:
 
 *	Dependency injection in java hides the service class dependencies that can lead to runtime errors that would have been caught at compile time.
-* While the pattern is great when creating predefined objects, adding the new ones might be challenging.
-* The code may become more complicated than it should be, since a lot of new interfaces and classes are introduced along with the pattern.
 
 
 ## Tutorial
 * [Abstract Factory Pattern Tutorial](https://www.journaldev.com/1418/abstract-factory-design-pattern-in-java) 
 
+## Presentations
+
+* [Abstract Factory Pattern](etc/presentation.html) 
+
 
 ## Real world examples
 

abstract-factory/etc/presentation.html

@@ -0,0 +1,190 @@
+<!--
+
+    The MIT License
+    Copyright (c) 2017 Rodolfo Forte
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Design Patterns - Abstract Factory Presentation</title>
+    <meta charset="utf-8">
+    <style>
+      @import url(https://fonts.googleapis.com/css?family=Yanone+Kaffeesatz);
+      @import url(https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic);
+      @import url(https://fonts.googleapis.com/css?family=Ubuntu+Mono:400,700,400italic);
+
+      body { font-family: 'Droid Serif'; }
+      h1, h2, h3 {
+        font-family: 'Yanone Kaffeesatz';
+        font-weight: normal;
+      }
+      .remark-code, .remark-inline-code { font-family: 'Ubuntu Mono'; }
+	  
+	  blockquote {
+		border-left: 0.3em solid rgba(0,0,0,0.5);
+		padding: 0 15px;
+		font-style: italic;
+	  }
+	  
+	  img {
+		max-width:100%;
+	  }
+    </style>
+  </head>
+  <body>
+    <textarea id="source">
+
+class: center, middle
+
+# Abstract Factory
+
+---
+
+# Also known as
+
+* Kit
+
+---
+
+# Intent
+
+* Provide an interface for creating families of related or dependent objects without specifying their concrete classes
+
+---
+
+# Explanation
+
+* [Wikipedia](https://en.wikipedia.org/wiki/Abstract_factory_pattern) says:
+  > "The abstract factory pattern provides a way to encapsulate a group of individual factories that have a common theme without specifying their concrete classes"
+
+<br />
+
+* In plain words:
+  * A factory that groups individual but related/dependent factories together without specifying their concrete classes;
+  * A factory of factories; 
+
+---
+
+# Example
+
+* In a factory that creates kingdoms, we need objects with common theme:
+
+  * Elven kingdom needs an Elven king, Elven castle and Elven army;
+  
+  * Orcish kingdom needs an Orcish king, Orcish castle and Orcish army;
+
+<br />
+  
+* There is a dependency between the objects in the kingdom;
+
+---
+
+# Diagram
+
+* Based on the kingdom example, the diagram below showcases the different concrete factories and their concrete products:
+
+.center[![Diagram](diagram1.png)]
+
+
+---
+
+# Diagram
+
+* The class diagram below showcases the factory of factories;
+
+* At runtime, we can define which Kingdom type is needed and pass it as a parameter to define which concrete KingdomFactory to instantiate;
+
+* The concrete factory returned will then be able to produce the related objects of the specified type;
+  
+.center[![Diagram](diagram2.png)]
+
+---
+
+# Applicability
+
+Use the Abstract Factory pattern when:
+
+* A system should be independent of how its products are created, composed and represented;
+
+* A system should be configured with one of multiple families of products;
+
+* A family of related product objects is designed to be used together, and you need to enforce this constraint;
+
+* You want to provide a class library of products, and you want to reveal just their interfaces, not their implementations;
+
+---
+
+# Applicability
+
+Use the Abstract Factory pattern when:
+
+* The lifetime of the dependency is conceptually shorter than the lifetime of the consumer;
+
+* You need a run-time value to construct a particular dependency;
+
+* You want to decide which product to call from a family at runtime;
+
+* You need to supply one or more parameters only known at run-time before you can resolve a dependency;
+
+---
+
+#Use Cases
+
+* Selecting to call the appropriate implementation of FileSystemAcmeService or DatabaseAcmeService or NetworkAcmeService at runtime;
+* Unit test case writing becomes much easier;
+
+---
+
+# Consequences
+
+* Dependency injection in java hides the service class dependencies that can lead to runtime errors that would have been caught at compile time
+
+---
+
+# Real world examples
+
+[javax.xml.parsers.DocumentBuilderFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/DocumentBuilderFactory.html)
+
+[javax.xml.transform.TransformerFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/transform/TransformerFactory.html#newInstance--)
+
+[javax.xml.xpath.XPathFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/xpath/XPathFactory.html#newInstance--)
+
+---
+
+# Credits
+
+* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)
+
+---
+
+# Tutorials
+
+* Source code http://java-design-patterns.com/patterns/abstract-factory/
+
+    </textarea>
+    <script src="https://gnab.github.io/remark/downloads/remark-latest.min.js">
+    </script>
+    <script>
+      var slideshow = remark.create();
+    </script>
+  </body>
+</html>

abstract-factory/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,10 +29,15 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.21.0-SNAPSHOT</version>
   </parent>
   <artifactId>abstract-factory</artifactId>
   <dependencies>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-engine</artifactId>

abstract-factory/src/main/java/com/iluwatar/abstractfactory/App.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,26 +20,27 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
-import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
+
 /**
- * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that
- * have a common theme without specifying their concrete classes. In normal usage, the client
- * software creates a concrete implementation of the abstract factory and then uses the generic
- * interface of the factory to create the concrete objects that are part of the theme. The client
- * does not know (or care) which concrete objects it gets from each of these internal factories,
- * since it uses only the generic interfaces of their products. This pattern separates the details
- * of implementation of a set of objects from their general usage and relies on object composition,
- * as object creation is implemented in methods exposed in the factory interface.
- *
- * <p>The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory})
- * and its implementations ( {@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses
- * both concrete implementations to create a king, a castle and an army.
+ * 
+ * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that have a common theme
+ * without specifying their concrete classes. In normal usage, the client software creates a concrete implementation of
+ * the abstract factory and then uses the generic interface of the factory to create the concrete objects that are part
+ * of the theme. The client does not know (or care) which concrete objects it gets from each of these internal
+ * factories, since it uses only the generic interfaces of their products. This pattern separates the details of
+ * implementation of a set of objects from their general usage and relies on object composition, as object creation is
+ * implemented in methods exposed in the factory interface.
+ * <p>
+ * The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory}) and its implementations (
+ * {@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses both concrete implementations to create a
+ * king, a castle and an army.
+ * 
  */
 public class App {
 
@@ -50,14 +51,14 @@ public class App {
   private Army army;
 
   /**
-   * Creates kingdom.
+   * Creates kingdom
    */
   public void createKingdom(final KingdomFactory factory) {
     setKing(factory.createKing());
     setCastle(factory.createCastle());
     setArmy(factory.createArmy());
   }
-
+  
   King getKing(final KingdomFactory factory) {
     return factory.createKing();
   }
@@ -69,7 +70,7 @@ public class App {
   private void setKing(final King king) {
     this.king = king;
   }
-
+  
   Castle getCastle(final KingdomFactory factory) {
     return factory.createCastle();
   }
@@ -81,7 +82,7 @@ public class App {
   private void setCastle(final Castle castle) {
     this.castle = castle;
   }
-
+  
   Army getArmy(final KingdomFactory factory) {
     return factory.createArmy();
   }
@@ -123,12 +124,13 @@ public class App {
 
   /**
    * Program entry point.
-   *
-   * @param args command line args
+   * 
+   * @param args
+   *          command line args
    */
   public static void main(String[] args) {
 
-    var app = new App();
+    App app = new App();
 
     LOGGER.info("Elf Kingdom");
     app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));

abstract-factory/src/main/java/com/iluwatar/abstractfactory/Army.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * Army interface.
+ * 
+ * Army interface
+ *
  */
 public interface Army {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/Castle.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * Castle interface.
+ * 
+ * Castle interface
+ *
  */
 public interface Castle {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfArmy.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * ElfArmy.
+ * 
+ * ElfArmy
+ *
  */
 public class ElfArmy implements Army {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfCastle.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * ElfCastle.
+ * 
+ * ElfCastle
+ *
  */
 public class ElfCastle implements Castle {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKing.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * ElfKing.
+ * 
+ * ElfKing
+ *
  */
 public class ElfKing implements King {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKingdomFactory.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,25 +20,23 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
+ * 
  * ElfKingdomFactory concrete factory.
+ * 
  */
 public class ElfKingdomFactory implements KingdomFactory {
 
-  @Override
   public Castle createCastle() {
     return new ElfCastle();
   }
 
-  @Override
   public King createKing() {
     return new ElfKing();
   }
 
-  @Override
   public Army createArmy() {
     return new ElfArmy();
   }

abstract-factory/src/main/java/com/iluwatar/abstractfactory/King.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * King interface.
+ * 
+ * King interface
+ *
  */
 public interface King {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/KingdomFactory.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
+ * 
  * KingdomFactory factory interface.
+ * 
  */
 public interface KingdomFactory {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcArmy.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * OrcArmy.
+ * 
+ * OrcArmy
+ *
  */
 public class OrcArmy implements Army {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcCastle.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * OrcCastle.
+ * 
+ * OrcCastle
+ *
  */
 public class OrcCastle implements Castle {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKing.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
- * OrcKing.
+ * 
+ * OrcKing
+ *
  */
 public class OrcKing implements King {
 

abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKingdomFactory.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,25 +20,23 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 /**
+ * 
  * OrcKingdomFactory concrete factory.
+ * 
  */
 public class OrcKingdomFactory implements KingdomFactory {
 
-  @Override
   public Castle createCastle() {
     return new OrcCastle();
   }
 
-  @Override
   public King createKing() {
     return new OrcKing();
   }
 
-  @Override
   public Army createArmy() {
     return new OrcArmy();
   }

abstract-factory/src/test/java/com/iluwatar/abstractfactory/AbstractFactoryTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -28,11 +27,12 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import com.iluwatar.abstractfactory.App.FactoryMaker;
 import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
+
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 /**
- * Test for abstract factory.
+ * Test for abstract factory
  */
 public class AbstractFactoryTest {
 
@@ -48,30 +48,30 @@ public class AbstractFactoryTest {
 
   @Test
   public void king() {
-    final var elfKing = app.getKing(elfFactory);
+    final King elfKing = app.getKing(elfFactory);
     assertTrue(elfKing instanceof ElfKing);
     assertEquals(ElfKing.DESCRIPTION, elfKing.getDescription());
-    final var orcKing = app.getKing(orcFactory);
+    final King orcKing = app.getKing(orcFactory);
     assertTrue(orcKing instanceof OrcKing);
     assertEquals(OrcKing.DESCRIPTION, orcKing.getDescription());
   }
 
   @Test
   public void castle() {
-    final var elfCastle = app.getCastle(elfFactory);
+    final Castle elfCastle = app.getCastle(elfFactory);
     assertTrue(elfCastle instanceof ElfCastle);
     assertEquals(ElfCastle.DESCRIPTION, elfCastle.getDescription());
-    final var orcCastle = app.getCastle(orcFactory);
+    final Castle orcCastle = app.getCastle(orcFactory);
     assertTrue(orcCastle instanceof OrcCastle);
     assertEquals(OrcCastle.DESCRIPTION, orcCastle.getDescription());
   }
 
   @Test
   public void army() {
-    final var elfArmy = app.getArmy(elfFactory);
+    final Army elfArmy = app.getArmy(elfFactory);
     assertTrue(elfArmy instanceof ElfArmy);
     assertEquals(ElfArmy.DESCRIPTION, elfArmy.getDescription());
-    final var orcArmy = app.getArmy(orcFactory);
+    final Army orcArmy = app.getArmy(orcFactory);
     assertTrue(orcArmy instanceof OrcArmy);
     assertEquals(OrcArmy.DESCRIPTION, orcArmy.getDescription());
   }
@@ -79,9 +79,9 @@ public class AbstractFactoryTest {
   @Test
   public void createElfKingdom() {
     app.createKingdom(elfFactory);
-    final var king = app.getKing();
-    final var castle = app.getCastle();
-    final var army = app.getArmy();
+    final King king = app.getKing();
+    final Castle castle = app.getCastle();
+    final Army army = app.getArmy();
     assertTrue(king instanceof ElfKing);
     assertEquals(ElfKing.DESCRIPTION, king.getDescription());
     assertTrue(castle instanceof ElfCastle);
@@ -93,9 +93,9 @@ public class AbstractFactoryTest {
   @Test
   public void createOrcKingdom() {
     app.createKingdom(orcFactory);
-    final var king = app.getKing();
-    final var castle = app.getCastle();
-    final var army = app.getArmy();
+    final King king = app.getKing();
+    final Castle castle = app.getCastle();
+    final Army army = app.getArmy();
     assertTrue(king instanceof OrcKing);
     assertEquals(OrcKing.DESCRIPTION, king.getDescription());
     assertTrue(castle instanceof OrcCastle);

abstract-factory/src/test/java/com/iluwatar/abstractfactory/AppTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,17 +20,19 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.abstractfactory;
 
 import org.junit.jupiter.api.Test;
 
+import java.io.IOException;
+
 /**
  * Tests that Abstract Factory example runs without errors.
  */
 public class AppTest {
   @Test
-  public void test() {
-    App.main(new String[]{});
+  public void test() throws IOException {
+    String[] args = {};
+    App.main(args);
   }
 }

acyclic-visitor/README.md

@@ -33,7 +33,7 @@ The bad:
 * Parallel hierarchy of visitors has to be created for all members in visitable class hierarchy.
 
 ## Related patterns
-* [Visitor Pattern](../visitor/)
+* [Visitor Pattern](../visitor/README.md)
 
 ## Credits
-* [Acyclic Visitor](http://condor.depaul.edu/dmumaugh/OOT/Design-Principles/acv.pdf)
+* [Acyclic Visitor](http://condor.depaul.edu/dmumaugh/OOT/Design-Principles/acv.pdf)

acyclic-visitor/pom.xml

@@ -1,7 +1,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -30,7 +30,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.22.0-SNAPSHOT</version>
+		<version>1.21.0-SNAPSHOT</version>
 	</parent>
 	
 	<artifactId>acyclic-visitor</artifactId>
@@ -56,6 +56,11 @@
 			<version>1.0.0</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+      		<groupId>org.junit.jupiter</groupId>
+      		<artifactId>junit-jupiter-api</artifactId>
+      		<scope>test</scope>
+    	</dependency>
     	<dependency>
       		<groupId>org.junit.jupiter</groupId>
       		<artifactId>junit-jupiter-engine</artifactId>

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/AllModemVisitor.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,13 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 /**
- * All ModemVisitor interface extends all visitor interfaces. This interface provides ease of use
- * when a visitor needs to visit all modem types.
+ * All ModemVisitor interface extends all visitor interfaces. This interface
+ * provides ease of use when a visitor needs to visit all modem types.
  */
-public interface AllModemVisitor extends ZoomVisitor, HayesVisitor {
+public interface AllModemVisitor extends ZoomVisitor, HayesVisitor{
 
 }

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/App.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,33 +20,34 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 /**
- * The Acyclic Visitor pattern allows new functions to be added to existing class hierarchies
- * without affecting those hierarchies, and without creating the dependency cycles that are inherent
- * to the GoF Visitor pattern, by making the Visitor base class degenerate
- *
- * <p>In this example the visitor base class is {@link ModemVisitor}. The base class of the visited
- * hierarchy is {@link Modem} and has two children {@link Hayes} and {@link Zoom} each one having
- * its own visitor interface {@link HayesVisitor} and {@link ZoomVisitor} respectively. {@link
- * ConfigureForUnixVisitor} and {@link ConfigureForDosVisitor} implement each derivative's visit
- * method only if it is required
+ * The Acyclic Visitor pattern allows new functions to be added to existing class 
+ * hierarchies without affecting those hierarchies, and without creating the dependency 
+ * cycles that are inherent to the GoF Visitor pattern, by making the Visitor base class 
+ * degenerate
+ * <p>
+ * In this example the visitor base class is {@link ModemVisitor}. The base class of the 
+ * visited hierarchy is {@link Modem} and has two children {@link Hayes} and {@link Zoom} 
+ * each one having its own visitor interface {@link HayesVisitor} and {@link ZoomVisitor} 
+ * respectively. {@link ConfigureForUnixVisitor} and {@link ConfigureForDosVisitor} 
+ * implement each derivative's visit method only if it is required 
  */
 public class App {
-
+  
   /**
-   * Program's entry point.
+   * Program's entry point
    */
-  public static void main(String[] args) {
-    var conUnix = new ConfigureForUnixVisitor();
-    var conDos = new ConfigureForDosVisitor();
-
-    var zoom = new Zoom();
-    var hayes = new Hayes();
-
-    hayes.accept(conDos); // Hayes modem with Dos configurator
+  
+  public static void main(String[] args) {  
+    ConfigureForUnixVisitor conUnix = new ConfigureForUnixVisitor();
+    ConfigureForDosVisitor conDos = new ConfigureForDosVisitor();
+    
+    Zoom zoom = new Zoom();
+    Hayes hayes = new Hayes();
+    
+    hayes.accept(conDos); // Hayes modem with Unix configurator
     zoom.accept(conDos); // Zoom modem with Dos configurator
     hayes.accept(conUnix); // Hayes modem with Unix configurator
     zoom.accept(conUnix); // Zoom modem with Unix configurator   

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitor.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,26 +20,23 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * ConfigureForDosVisitor class implements both zoom's and  hayes' visit method for Dos
- * manufacturer.
+ * ConfigureForDosVisitor class implements both zoom's and  hayes' visit method 
+ * for Dos manufacturer
  */
 public class ConfigureForDosVisitor implements AllModemVisitor {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForDosVisitor.class);
 
-  @Override
   public void visit(Hayes hayes) {
     LOGGER.info(hayes + " used with Dos configurator.");
   }
 
-  @Override
   public void visit(Zoom zoom) {
     LOGGER.info(zoom + " used with Dos configurator.");
   }

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitor.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,21 +20,20 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * ConfigureForUnixVisitor class implements zoom's visit method for Unix manufacturer, unlike
- * traditional visitor pattern, this class may selectively implement visit for other modems.
+ * ConfigureForUnixVisitor class implements zoom's visit method for Unix 
+ * manufacturer, unlike traditional visitor pattern, this class may selectively implement
+ * visit for other modems.
  */
 public class ConfigureForUnixVisitor implements ZoomVisitor {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForUnixVisitor.class);
 
-  @Override
   public void visit(Zoom zoom) {
     LOGGER.info(zoom + " used with Unix configurator.");
   }

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Hayes.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,21 +20,20 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Hayes class implements its accept method.
+ * Hayes class implements its accept method
  */
 public class Hayes extends Modem {
-
+  
   private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForDosVisitor.class);
 
   /**
-   * Accepts all visitors but honors only HayesVisitor.
+   * Accepts all visitors but honors only HayesVisitor
    */
   @Override
   public void accept(ModemVisitor modemVisitor) {
@@ -45,9 +44,10 @@ public class Hayes extends Modem {
     }
 
   }
-
+  
   /**
-   * Hayes' modem's toString method.
+   * Hayes' modem's toString
+   * method
    */
   @Override
   public String toString() {

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/HayesVisitor.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,10 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 /**
- * HayesVisitor interface.
+ * HayesVisitor interface
  */
 public interface HayesVisitor extends ModemVisitor {
   void visit(Hayes hayes);

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Modem.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,10 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 /**
- * Modem abstract class.
+ * Modem abstract class
  */
 public abstract class Modem {
   public abstract void accept(ModemVisitor modemVisitor);

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ModemVisitor.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,12 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 /**
- * ModemVisitor interface does not contain any visit methods so that it does not depend on the
- * visited hierarchy. Each derivative's visit method is declared in its own visitor interface
+ * ModemVisitor interface does not contain any visit methods so that it does not
+ * depend on the visited hierarchy. Each derivative's visit method is declared in 
+ * its own visitor interface
  */
 public interface ModemVisitor {
   // Visitor is a degenerate base class for all visitors.

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Zoom.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,33 +20,33 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * Zoom class implements its accept method.
+ * Zoom class implements its accept method
  */
 public class Zoom extends Modem {
-
+  
   private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForDosVisitor.class);
 
   /**
-   * Accepts all visitors but honors only ZoomVisitor.
+   * Accepts all visitors but honors only ZoomVisitor
    */
   @Override
   public void accept(ModemVisitor modemVisitor) {
-    if (modemVisitor instanceof ZoomVisitor) {
+    if (modemVisitor instanceof  ZoomVisitor) {
       ((ZoomVisitor) modemVisitor).visit(this);
     } else {
       LOGGER.info("Only ZoomVisitor is allowed to visit Zoom modem");
     }
   }
-
+  
   /**
-   * Zoom modem's toString method.
+   * Zoom modem's toString
+   * method
    */
   @Override
   public String toString() {

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ZoomVisitor.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,10 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 /**
- * ZoomVisitor interface.
+ * ZoomVisitor interface
  */
 public interface ZoomVisitor extends ModemVisitor {
   void visit(Zoom zoom);

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/AppTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,18 +20,20 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 import org.junit.jupiter.api.Test;
 
+import com.iluwatar.acyclicvisitor.App;
+
 /**
  * Tests that the Acyclic Visitor example runs without errors.
  */
 public class AppTest {
-
+  
   @Test
   public void test() {
-    App.main(new String[]{});
+    String[] args = {};
+    App.main(args);  
   }
 }

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,15 +20,22 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.groups.Tuple.tuple;
+import static org.mockito.Mockito.mock;
 import static uk.org.lidalia.slf4jext.Level.INFO;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
+
+import com.iluwatar.acyclicvisitor.ConfigureForDosVisitor;
+import com.iluwatar.acyclicvisitor.Hayes;
+import com.iluwatar.acyclicvisitor.HayesVisitor;
+import com.iluwatar.acyclicvisitor.Zoom;
+import com.iluwatar.acyclicvisitor.ZoomVisitor;
+
 import uk.org.lidalia.slf4jtest.TestLogger;
 import uk.org.lidalia.slf4jtest.TestLoggerFactory;
 
@@ -37,30 +44,28 @@ import uk.org.lidalia.slf4jtest.TestLoggerFactory;
  */
 public class ConfigureForDosVisitorTest {
 
-  private TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class);
+  TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class);
   
   @Test
   public void testVisitForZoom() {    
-    var conDos = new ConfigureForDosVisitor();
-    var zoom = new Zoom();
+    ConfigureForDosVisitor conDos = new ConfigureForDosVisitor();
+    Zoom zoom = new Zoom();
     
     conDos.visit(zoom);
     
-    assertThat(logger.getLoggingEvents())
-        .extracting("level", "message")
-        .contains(tuple(INFO, zoom + " used with Dos configurator."));
+    assertThat(logger.getLoggingEvents()).extracting("level", "message").contains(
+        tuple(INFO, zoom + " used with Dos configurator."));
   }
   
   @Test
   public void testVisitForHayes() {
-    var conDos = new ConfigureForDosVisitor();
-    var hayes = new Hayes();
+    ConfigureForDosVisitor conDos = new ConfigureForDosVisitor();
+    Hayes hayes = new Hayes();
     
     conDos.visit(hayes);
     
-    assertThat(logger.getLoggingEvents())
-        .extracting("level", "message")
-        .contains(tuple(INFO, hayes + " used with Dos configurator."));
+    assertThat(logger.getLoggingEvents()).extracting("level", "message").contains(
+        tuple(INFO, hayes + " used with Dos configurator."));
   }
   
   @AfterEach

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -47,13 +46,12 @@ public class ConfigureForUnixVisitorTest {
   
   @Test
   public void testVisitForZoom() {
-    var conUnix = new ConfigureForUnixVisitor();
-    var zoom = new Zoom();
+    ConfigureForUnixVisitor conUnix = new ConfigureForUnixVisitor();
+    Zoom zoom = new Zoom();
     
     conUnix.visit(zoom);
     
-    assertThat(LOGGER.getLoggingEvents())
-        .extracting("level", "message")
-        .contains(tuple(INFO, zoom + " used with Unix configurator."));
+    assertThat(LOGGER.getLoggingEvents()).extracting("level", "message").contains(
+        tuple(INFO, zoom + " used with Unix configurator."));
   }
 }

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/HayesTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 import static org.mockito.Matchers.eq;
@@ -30,6 +29,11 @@ import static org.mockito.Mockito.verifyZeroInteractions;
 
 import org.junit.jupiter.api.Test;
 
+import com.iluwatar.acyclicvisitor.ConfigureForDosVisitor;
+import com.iluwatar.acyclicvisitor.ConfigureForUnixVisitor;
+import com.iluwatar.acyclicvisitor.Hayes;
+import com.iluwatar.acyclicvisitor.HayesVisitor;
+
 /**
  * Hayes test class
  */
@@ -37,8 +41,8 @@ public class HayesTest {
 
   @Test
   public void testAcceptForDos() {  
-    var hayes = new Hayes();
-    var mockVisitor = mock(ConfigureForDosVisitor.class);
+    Hayes hayes = new Hayes();
+    ConfigureForDosVisitor mockVisitor = mock(ConfigureForDosVisitor.class);
     
     hayes.accept(mockVisitor);
     verify((HayesVisitor)mockVisitor).visit(eq(hayes));
@@ -46,8 +50,8 @@ public class HayesTest {
   
   @Test
   public void testAcceptForUnix() {    
-    var hayes = new Hayes();
-    var mockVisitor = mock(ConfigureForUnixVisitor.class);
+    Hayes hayes = new Hayes();
+    ConfigureForUnixVisitor mockVisitor = mock(ConfigureForUnixVisitor.class);
     
     hayes.accept(mockVisitor);
     

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ZoomTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.acyclicvisitor;
 
 
@@ -30,6 +29,11 @@ import static org.mockito.Mockito.mock;
 
 import org.junit.jupiter.api.Test;
 
+import com.iluwatar.acyclicvisitor.ConfigureForDosVisitor;
+import com.iluwatar.acyclicvisitor.ConfigureForUnixVisitor;
+import com.iluwatar.acyclicvisitor.Zoom;
+import com.iluwatar.acyclicvisitor.ZoomVisitor;
+
 /**
  * Zoom test class
  */
@@ -37,8 +41,8 @@ public class ZoomTest {
   
   @Test
   public void testAcceptForDos() {  
-    var zoom = new Zoom();
-    var mockVisitor = mock(ConfigureForDosVisitor.class);
+    Zoom zoom = new Zoom();
+    ConfigureForDosVisitor mockVisitor = mock(ConfigureForDosVisitor.class);
     
     zoom.accept(mockVisitor);
     verify((ZoomVisitor)mockVisitor).visit(eq(zoom));
@@ -46,8 +50,8 @@ public class ZoomTest {
   
   @Test
   public void testAcceptForUnix() {
-    var zoom = new Zoom();
-    var mockVisitor = mock(ConfigureForUnixVisitor.class);
+    Zoom zoom = new Zoom();
+    ConfigureForUnixVisitor mockVisitor = mock(ConfigureForUnixVisitor.class);
     
     zoom.accept(mockVisitor);
     verify((ZoomVisitor)mockVisitor).visit(eq(zoom));

adapter/README.md

@@ -56,14 +56,15 @@ public class FishingBoat {
 And captain expects an implementation of `RowingBoat` interface to be able to move
 
 ```java
-public class Captain {
+public class Captain implements RowingBoat {
 
   private RowingBoat rowingBoat;
-  // default constructor and setter for rowingBoat
+
   public Captain(RowingBoat rowingBoat) {
     this.rowingBoat = rowingBoat;
   }
 
+  @Override
   public void row() {
     rowingBoat.row();
   }
@@ -93,7 +94,7 @@ public class FishingBoatAdapter implements RowingBoat {
 And now the `Captain` can use the `FishingBoat` to escape the pirates.
 
 ```java
-var captain = new Captain(new FishingBoatAdapter());
+Captain captain = new Captain(new FishingBoatAdapter());
 captain.row();
 ```
 

adapter/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,10 +29,15 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.21.0-SNAPSHOT</version>
   </parent>
   <artifactId>adapter</artifactId>
   <dependencies>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-engine</artifactId>

adapter/src/main/java/com/iluwatar/adapter/App.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.adapter;
 
 /**
@@ -29,33 +28,33 @@ package com.iluwatar.adapter;
  * The Adapter design pattern allows otherwise incompatible classes to work together by converting
  * the interface of one class into an interface expected by the clients.
  *
- * <p>There are two variations of the Adapter pattern: The class adapter implements the adaptee's
+ * <p>
+ * There are two variations of the Adapter pattern: The class adapter implements the adaptee's
  * interface whereas the object adapter uses composition to contain the adaptee in the adapter
  * object. This example uses the object adapter approach.
  *
- * <p>The Adapter ({@link FishingBoatAdapter}) converts the interface of the adaptee class ({@link
- * FishingBoat}) into a suitable one expected by the client ({@link RowingBoat}).
+ * <p>
+ * The Adapter ({@link FishingBoatAdapter}) converts the interface of the adaptee class (
+ * {@link FishingBoat}) into a suitable one expected by the client ( {@link RowingBoat} ).
+ *
+ * <p>
+ * The story of this implementation is this. <br>
+ * Pirates are coming! we need a {@link RowingBoat} to flee! We have a {@link FishingBoat} and our
+ * captain. We have no time to make up a new ship! we need to reuse this {@link FishingBoat}. The
+ * captain needs a rowing boat which he can operate. The spec is in {@link RowingBoat}. We will
+ * use the Adapter pattern to reuse {@link FishingBoat}.
  *
- * <p>The story of this implementation is this. <br> Pirates are coming! we need a {@link
- * RowingBoat} to flee! We have a {@link FishingBoat} and our captain. We have no time to make up a
- * new ship! we need to reuse this {@link FishingBoat}. The captain needs a rowing boat which he can
- * operate. The spec is in {@link RowingBoat}. We will use the Adapter pattern to reuse {@link
- * FishingBoat}.
  */
-public final class App {
-
-  private App() {
-  }
+public class App {
 
   /**
    * Program entry point.
    *
    * @param args command line args
    */
-  public static void main(final String[] args) {
-    // The captain can only operate rowing boats but with adapter he is able to
-    // use fishing boats as well
-    var captain = new Captain(new FishingBoatAdapter());
+  public static void main(String[] args) {
+    // The captain can only operate rowing boats but with adapter he is able to use fishing boats as well
+    Captain captain = new Captain(new FishingBoatAdapter());
     captain.row();
   }
 }

adapter/src/main/java/com/iluwatar/adapter/Captain.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,28 +20,27 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.adapter;
 
 /**
- * The Captain uses {@link RowingBoat} to sail. <br> This is the client in the pattern.
+ * The Captain uses {@link RowingBoat} to sail. <br>
+ * This is the client in the pattern.
  */
-public final class Captain {
+public class Captain {
 
   private RowingBoat rowingBoat;
 
-  public Captain() {
+  public Captain() {}
+
+  public Captain(RowingBoat rowingBoat) {
+    this.rowingBoat = rowingBoat;
   }
 
-  public Captain(final RowingBoat boat) {
-    this.rowingBoat = boat;
+  public void setRowingBoat(RowingBoat rowingBoat) {
+    this.rowingBoat = rowingBoat;
   }
 
-  void setRowingBoat(final RowingBoat boat) {
-    this.rowingBoat = boat;
-  }
-
-  void row() {
+  public void row() {
     rowingBoat.row();
   }
 

adapter/src/main/java/com/iluwatar/adapter/FishingBoat.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,22 +20,22 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.adapter;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
 import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * Device class (adaptee in the pattern). We want to reuse this class. Fishing boat moves by
- * sailing.
+ *
+ * Device class (adaptee in the pattern). We want to reuse this class.
+ * Fishing boat moves by sailing.
+ *
  */
-final class FishingBoat {
+public class FishingBoat {
 
-  private static final Logger LOGGER = getLogger(FishingBoat.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoat.class);
 
-  void sail() {
+  public void sail() {
     LOGGER.info("The fishing boat is sailing");
   }
 

adapter/src/main/java/com/iluwatar/adapter/FishingBoatAdapter.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,12 +20,13 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.adapter;
 
 /**
+ *
  * Adapter class. Adapts the interface of the device ({@link FishingBoat}) into {@link RowingBoat}
  * interface expected by the client ({@link Captain}).
+ *
  */
 public class FishingBoatAdapter implements RowingBoat {
 
@@ -35,7 +36,8 @@ public class FishingBoatAdapter implements RowingBoat {
     boat = new FishingBoat();
   }
 
-  public final void row() {
+  @Override
+  public void row() {
     boat.sail();
   }
 }

adapter/src/main/java/com/iluwatar/adapter/RowingBoat.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,11 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.adapter;
 
 /**
- * The interface expected by the client.<br> A rowing boat is rowed to move.
+ * The interface expected by the client.<br>
+ * A rowing boat is rowed to move.
+ *
  */
 public interface RowingBoat {
 

adapter/src/main/java/com/iluwatar/adapter/package-info.java

@@ -1,24 +0,0 @@
-/*
- * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-package com.iluwatar.adapter;

adapter/src/test/java/com/iluwatar/adapter/AdapterPatternTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,19 +20,20 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.adapter;
 
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 
-import java.util.HashMap;
-import java.util.Map;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
 /**
  * Test class
+ * 
  */
 public class AdapterPatternTest {
 
@@ -49,29 +50,29 @@ public class AdapterPatternTest {
   public void setup() {
     beans = new HashMap<>();
 
-    var fishingBoatAdapter = spy(new FishingBoatAdapter());
+    FishingBoatAdapter fishingBoatAdapter = spy(new FishingBoatAdapter());
     beans.put(FISHING_BEAN, fishingBoatAdapter);
 
-    var captain = new Captain();
+    Captain captain = new Captain();
     captain.setRowingBoat((FishingBoatAdapter) beans.get(FISHING_BEAN));
     beans.put(ROWING_BEAN, captain);
   }
 
   /**
-   * This test asserts that when we use the row() method on a captain bean(client), it is internally
-   * calling sail method on the fishing boat object. The Adapter ({@link FishingBoatAdapter} )
-   * converts the interface of the target class ( {@link FishingBoat}) into a suitable one expected
-   * by the client ({@link Captain} ).
+   * This test asserts that when we use the row() method on a captain bean(client), it is
+   * internally calling sail method on the fishing boat object. The Adapter ({@link FishingBoatAdapter}
+   * ) converts the interface of the target class ( {@link FishingBoat}) into a suitable one
+   * expected by the client ({@link Captain} ).
    */
   @Test
   public void testAdapter() {
-    var captain = (Captain) beans.get(ROWING_BEAN);
+    Captain captain = (Captain) beans.get(ROWING_BEAN);
 
     // when captain moves
     captain.row();
 
     // the captain internally calls the battleship object to move
-    var adapter = (RowingBoat) beans.get(FISHING_BEAN);
+    RowingBoat adapter = (RowingBoat) beans.get(FISHING_BEAN);
     verify(adapter).row();
   }
 }

adapter/src/test/java/com/iluwatar/adapter/AppTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,17 +20,19 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.adapter;
 
 import org.junit.jupiter.api.Test;
 
+import java.io.IOException;
+
 /**
  * Tests that Adapter example runs without errors.
  */
 public class AppTest {
   @Test
-  public void test() {
-    App.main(new String[]{});
+  public void test() throws IOException {
+    String[] args = {};
+    App.main(args);
   }
 }

aggregator-microservices/aggregator-service/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,11 +29,21 @@
     <parent>
         <artifactId>aggregator-microservices</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
+        <version>1.21.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
+
     <artifactId>aggregator-service</artifactId>
     <packaging>jar</packaging>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
     <dependencies>
         <dependency>
             <groupId>org.springframework</groupId>
@@ -43,6 +53,11 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
@@ -53,6 +68,10 @@
             <artifactId>mockito-core</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+        </dependency>
     </dependencies>
 
     <build>
@@ -60,6 +79,7 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot.version}</version>
                 <executions>
                     <execution>
                         <goals>
@@ -70,4 +90,4 @@
             </plugin>
         </plugins>
     </build>
-</project>
+</project>

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,19 +20,16 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.aggregator.microservices;
 
-import static java.util.Objects.requireNonNullElse;
-
-import javax.annotation.Resource;
 import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 
+import javax.annotation.Resource;
+
 /**
- * The aggregator aggregates calls on various micro-services, collects data and further publishes
- * them under a REST endpoint.
+ * The aggregator aggregates calls on various micro-services, collects
+ * data and further publishes them under a REST endpoint.
  */
 @RestController
 public class Aggregator {
@@ -50,19 +47,11 @@ public class Aggregator {
    *
    * @return a Product.
    */
-  @RequestMapping(path = "/product", method = RequestMethod.GET)
+  @RequestMapping("/product")
   public Product getProduct() {
-
-    var product = new Product();
-    var productTitle = informationClient.getProductTitle();
-    var productInventory = inventoryClient.getProductInventories();
-
-    //Fallback to error message
-    product.setTitle(requireNonNullElse(productTitle, "Error: Fetching Product Title Failed"));
-
-    //Fallback to default error inventory
-    product.setProductInventories(requireNonNullElse(productInventory, -1));
-
+    Product product = new Product();
+    product.setTitle(informationClient.getProductTitle());
+    product.setProductInventories(inventoryClient.getProductInventories());
     return product;
   }
 

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/App.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,20 +20,19 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.aggregator.microservices;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
 /**
- * Spring Boot EntryPoint Class.
+ * Spring Boot EntryPoint Class
  */
 @SpringBootApplication
 public class App {
 
   /**
-   * Program entry point.
+   * Program entry point
    *
    * @param args command line args
    */

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Product.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.aggregator.microservices;
 
 /**

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClient.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.aggregator.microservices;
 
 /**

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,18 +20,19 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.aggregator.microservices;
 
-import java.io.IOException;
-import java.net.URI;
-import java.net.http.HttpClient;
-import java.net.http.HttpRequest;
-import java.net.http.HttpResponse;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.util.EntityUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Component;
 
+import java.io.IOException;
+
 /**
  * An adapter to communicate with information micro-service.
  */
@@ -42,19 +43,15 @@ public class ProductInformationClientImpl implements ProductInformationClient {
 
   @Override
   public String getProductTitle() {
-    var request = HttpRequest.newBuilder()
-        .GET()
-        .uri(URI.create("http://localhost:51515/information"))
-        .build();
-    var client = HttpClient.newHttpClient();
-    try {
-      var httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString());
-      return httpResponse.body();
-    } catch (IOException ioe) {
-      LOGGER.error("IOException Occurred", ioe);
-    } catch (InterruptedException ie) {
-      LOGGER.error("InterruptedException Occurred", ie);
+    String response = null;
+    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+      HttpGet httpGet = new HttpGet("http://localhost:51515/information");
+      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
+        response = EntityUtils.toString(httpResponse.getEntity());
+      }
+    } catch (IOException e) {
+      LOGGER.error("Exception caught.", e);
     }
-    return null;
+    return response;
   }
 }

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClient.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.aggregator.microservices;
 
 /**
@@ -28,5 +27,5 @@ package com.iluwatar.aggregator.microservices;
  */
 public interface ProductInventoryClient {
 
-  Integer getProductInventories();
+  int getProductInventories();
 }

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,18 +20,19 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.aggregator.microservices;
 
-import java.io.IOException;
-import java.net.URI;
-import java.net.http.HttpClient;
-import java.net.http.HttpRequest;
-import java.net.http.HttpResponse;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.util.EntityUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Component;
 
+import java.io.IOException;
+
 /**
  * An adapter to communicate with inventory micro-service.
  */
@@ -41,26 +42,16 @@ public class ProductInventoryClientImpl implements ProductInventoryClient {
   private static final Logger LOGGER = LoggerFactory.getLogger(ProductInventoryClientImpl.class);
 
   @Override
-  public Integer getProductInventories() {
-    var response = "";
-
-    var request = HttpRequest.newBuilder()
-        .GET()
-        .uri(URI.create("http://localhost:51516/inventories"))
-        .build();
-    var client = HttpClient.newHttpClient();
-    try {
-      var httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString());
-      response = httpResponse.body();
-    } catch (IOException ioe) {
-      LOGGER.error("IOException Occurred", ioe);
-    } catch (InterruptedException ie) {
-      LOGGER.error("InterruptedException Occurred", ie);
-    }
-    if ("".equalsIgnoreCase(response)) {
-      return null;
-    } else {
-      return Integer.parseInt(response);
+  public int getProductInventories() {
+    String response = "0";
+    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+      HttpGet httpGet = new HttpGet("http://localhost:51516/inventories");
+      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
+        response = EntityUtils.toString(httpResponse.getEntity());
+      }
+    } catch (IOException e) {
+      LOGGER.error("Exception caught.", e);
     }
+    return Integer.parseInt(response);
   }
 }

aggregator-microservices/aggregator-service/src/main/resources/application.properties

@@ -1,6 +1,6 @@
 #
 # The MIT License
-# Copyright © 2014-2019 Ilkka Seppälä
+# Copyright (c) 2014-2016 Ilkka Seppälä
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -20,4 +20,5 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 #
+
 server.port=50004

aggregator-microservices/aggregator-service/src/test/java/com/iluwatar/aggregator/microservices/AggregatorTest.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,18 +20,17 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.aggregator.microservices;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.mockito.Mockito.when;
-
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
+
 /**
  * Test Aggregation of domain objects
  */
@@ -56,13 +55,13 @@ public class AggregatorTest {
    */
   @Test
   public void testGetProduct() {
-    var title = "The Product Title.";
-    var inventories = 5;
+    String title = "The Product Title.";
+    int inventories = 5;
 
     when(informationClient.getProductTitle()).thenReturn(title);
     when(inventoryClient.getProductInventories()).thenReturn(inventories);
 
-    var testProduct = aggregator.getProduct();
+    Product testProduct = aggregator.getProduct();
 
     assertEquals(title, testProduct.getTitle());
     assertEquals(inventories, testProduct.getProductInventories());

aggregator-microservices/information-microservice/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,13 +29,21 @@
     <parent>
         <artifactId>aggregator-microservices</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
+        <version>1.21.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
     <artifactId>information-microservice</artifactId>
     <packaging>jar</packaging>
 
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
     <dependencies>
         <dependency>
             <groupId>org.springframework</groupId>
@@ -45,6 +53,11 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
@@ -57,6 +70,7 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot.version}</version>
                 <executions>
                     <execution>
                         <goals>

aggregator-microservices/information-microservice/src/main/java/com/iluwatar/information/microservice/InformationApplication.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.information.microservice;
 
 import org.springframework.boot.SpringApplication;

aggregator-microservices/information-microservice/src/main/java/com/iluwatar/information/microservice/InformationController.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.information.microservice;
 
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -28,7 +27,7 @@ import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 
 /**
- * Controller providing endpoints to retrieve information about products.
+ * Controller providing endpoints to retrieve information about products
  */
 @RestController
 public class InformationController {

aggregator-microservices/information-microservice/src/main/resources/application.properties

@@ -1,6 +1,6 @@
 #
 # The MIT License
-# Copyright © 2014-2019 Ilkka Seppälä
+# Copyright (c) 2014-2016 Ilkka Seppälä
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -20,4 +20,5 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 #
+
 server.port=51515

aggregator-microservices/information-microservice/src/test/java/com/iluwatar/information/microservice/InformationControllerTest.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,13 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.information.microservice;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  * Test for Information Rest Controller
  */
@@ -34,8 +33,10 @@ public class InformationControllerTest {
 
   @Test
   public void shouldGetProductTitle() {
-    var infoController = new InformationController();
-    var title = infoController.getProductTitle();
+    InformationController infoController = new InformationController();
+
+    String title = infoController.getProductTitle();
+
     assertEquals("The Product Title.", title);
   }
 

aggregator-microservices/inventory-microservice/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,12 +29,21 @@
     <parent>
         <artifactId>aggregator-microservices</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
+        <version>1.21.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
-    <artifactId>inventory-microservice</artifactId>
 
+    <artifactId>inventory-microservice</artifactId>
     <packaging>jar</packaging>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
     <dependencies>
         <dependency>
             <groupId>org.springframework</groupId>
@@ -44,6 +53,11 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
@@ -56,6 +70,7 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot.version}</version>
                 <executions>
                     <execution>
                         <goals>
@@ -66,4 +81,4 @@
             </plugin>
         </plugins>
     </build>
-</project>
+</project>

aggregator-microservices/inventory-microservice/src/main/java/com/iluwatar/inventory/microservice/InventoryApplication.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.inventory.microservice;
 
 import org.springframework.boot.SpringApplication;

aggregator-microservices/inventory-microservice/src/main/java/com/iluwatar/inventory/microservice/InventoryController.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.inventory.microservice;
 
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -28,7 +27,7 @@ import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 
 /**
- * Controller providing endpoints to retrieve product inventories.
+ * Controller providing endpoints to retrieve product inventories
  */
 @RestController
 public class InventoryController {

aggregator-microservices/inventory-microservice/src/main/resources/application.properties

@@ -1,6 +1,6 @@
 #
 # The MIT License
-# Copyright © 2014-2019 Ilkka Seppälä
+# Copyright (c) 2014-2016 Ilkka Seppälä
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -20,4 +20,5 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 #
+
 server.port=51516

aggregator-microservices/inventory-microservice/src/test/java/com/iluwatar/inventory/microservice/InventoryControllerTest.java

@@ -1,17 +1,17 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- *
+ * <p/>
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- *
+ * <p/>
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -20,21 +20,22 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.inventory.microservice;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  * Test Inventory Rest Controller
  */
 public class InventoryControllerTest {
   @Test
   public void testGetProductInventories() {
-    var inventoryController = new InventoryController();
-    var numberOfInventories = inventoryController.getProductInventories();
+    InventoryController inventoryController = new InventoryController();
+
+    int numberOfInventories = inventoryController.getProductInventories();
+
     assertEquals(5, numberOfInventories);
   }
 }

aggregator-microservices/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,7 +29,7 @@
     <parent>
         <artifactId>java-design-patterns</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
+        <version>1.21.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
     <artifactId>aggregator-microservices</artifactId>

ambassador/README.md

@@ -42,8 +42,8 @@ A remote services represented as a singleton.
 ```java
 public class RemoteService implements RemoteServiceInterface {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
-    private static RemoteService service = null;
+		private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
+    private static RemoteService service = null;2
 
     static synchronized RemoteService getRemoteService() {
         if (service == null) {
@@ -56,14 +56,14 @@ public class RemoteService implements RemoteServiceInterface {
 
     @Override
     public long doRemoteFunction(int value) {
+
         long waitTime = (long) Math.floor(Math.random() * 1000);
 
         try {
             sleep(waitTime);
         } catch (InterruptedException e) {
-            LOGGER.error("Thread sleep interrupted", e);
+            LOGGER.error("Thread sleep interrupted", e)
         }
-
         return waitTime >= 200 ? value * 10 : -1;
     }
 }
@@ -74,50 +74,53 @@ A service ambassador adding additional features such as logging, latency checks
 ```java
 public class ServiceAmbassador implements RemoteServiceInterface {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(ServiceAmbassador.class);
-  private static final int RETRIES = 3;
-  private static final int DELAY_MS = 3000;
+    private static final Logger LOGGER = LoggerFactory.getLogger(ServiceAmbassador.class);
+    private static final int RETRIES = 3;
+    private static final int DELAY_MS = 3000;
 
-  ServiceAmbassador() {
-  }
+    ServiceAmbassador() {}
 
-  @Override
-  public long doRemoteFunction(int value) {
-    return safeCall(value);
-  }
+    @Override
+    public long doRemoteFunction(int value) {
 
-  private long checkLatency(int value) {
-    var startTime = System.currentTimeMillis();
-    var result = RemoteService.getRemoteService().doRemoteFunction(value);
-    var timeTaken = System.currentTimeMillis() - startTime;
-
-    LOGGER.info("Time taken (ms): " + timeTaken);
-    return result;
-  }
-
-  private long safeCall(int value) {
-    var retries = 0;
-    var result = (long) FAILURE;
-
-    for (int i = 0; i < RETRIES; i++) {
-      if (retries >= RETRIES) {
-        return FAILURE;
-      }
-
-      if ((result = checkLatency(value)) == FAILURE) {
-        LOGGER.info("Failed to reach remote: (" + (i + 1) + ")");
-        retries++;
-        try {
-          sleep(DELAY_MS);
-        } catch (InterruptedException e) {
-          LOGGER.error("Thread sleep state interrupted", e);
-        }
-      } else {
-        break;
-      }
+        return safeCall(value);
+    }
+
+    private long checkLatency(int value) {
+        RemoteService service = RemoteService.getRemoteService();
+        long startTime = System.currentTimeMillis();
+        long result = service.doRemoteFunction(value);
+        long timeTaken = System.currentTimeMillis() - startTime;
+
+        LOGGER.info("Time taken (ms): " + timeTaken);
+        return result;
+    }
+
+    private long safeCall(int value) {
+
+        int retries = 0;
+        long result = -1;
+
+        for (int i = 0; i < RETRIES; i++) {
+
+            if (retries >= RETRIES) {
+                return -1;
+            }
+
+            if ((result = checkLatency(value)) == -1) {
+                LOGGER.info("Failed to reach remote: (" + (i + 1) + ")");
+                retries++;
+                try {
+                    sleep(DELAY_MS);
+                } catch (InterruptedException e) {
+                    LOGGER.error("Thread sleep state interrupted", e);
+                }
+            } else {
+                break;
+            }
+        }
+        return result;
     }
-    return result;
-  }
 }
 ```
 
@@ -126,28 +129,27 @@ A client has a local service ambassador used to interact with the remote service
 ```java
 public class Client {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(Client.class);
-  private final ServiceAmbassador serviceAmbassador = new ServiceAmbassador();
+    private ServiceAmbassador serviceAmbassador;
 
-  long useService(int value) {
-    var result = serviceAmbassador.doRemoteFunction(value);
-    LOGGER.info("Service result: " + result);
-    return result;
-  }
+    Client() {
+        serviceAmbassador = new ServiceAmbassador();
+    }
+
+    long useService(int value) {
+        long result = serviceAmbassador.doRemoteFunction(value);
+        LOGGER.info("Service result: " + result)
+        return result;
+    }
 }
 ```
 
 And here are two clients using the service.
 
 ```java
-public class App {
-  public static void main(String[] args) {
-    var host1 = new Client();
-    var host2 = new Client();
-    host1.useService(12);
-    host2.useService(73);
-  }
-}
+Client host1 = new Client();
+Client host2 = new Client();
+host1.useService(12);
+host2.useService(73);
 ```
 
 ## Applicability

ambassador/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,15 +29,20 @@
   <parent>
     <artifactId>java-design-patterns</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.21.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>ambassador</artifactId>
   <dependencies>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-engine</artifactId>
       <scope>test</scope>
     </dependency>
   </dependencies>
-</project>
+</project>

ambassador/src/main/java/com/iluwatar/ambassador/App.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,33 +20,33 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
 /**
+ *
  * The ambassador pattern creates a helper service that sends network requests on behalf of a
  * client. It is often used in cloud-based applications to offload features of a remote service.
  *
- * <p>An ambassador service can be thought of as an out-of-process proxy that is co-located with
- * the client. Similar to the proxy design pattern, the ambassador service provides an interface for
- * another remote service. In addition to the interface, the ambassador provides extra functionality
- * and features, specifically offloaded common connectivity tasks. This usually consists of
- * monitoring, logging, routing, security etc. This is extremely useful in legacy applications where
- * the codebase is difficult to modify and allows for improvements in the application's networking
- * capabilities.
+ * An ambassador service can be thought of as an out-of-process proxy that is co-located with
+ * the client. Similar to the proxy design pattern, the ambassador service provides an interface
+ * for another remote service. In addition to the interface, the ambassador provides extra
+ * functionality and features, specifically offloaded common connectivity tasks. This usually
+ * consists of monitoring, logging, routing, security etc. This is extremely useful in
+ * legacy applications where the codebase is difficult to modify and allows for improvements
+ * in the application's networking capabilities.
  *
- * <p>In this example, we will the ({@link ServiceAmbassador}) class represents the ambassador while
- * the
+ * In this example, we will the ({@link ServiceAmbassador}) class represents the ambassador while the
  * ({@link RemoteService}) class represents a remote application.
+ *
  */
 public class App {
 
   /**
-   * Entry point.
-   */
+  * Entry point
+  */
   public static void main(String[] args) {
-    var host1 = new Client();
-    var host2 = new Client();
+    Client host1 = new Client();
+    Client host2 = new Client();
     host1.useService(12);
     host2.useService(73);
   }

ambassador/src/main/java/com/iluwatar/ambassador/Client.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,14 +20,14 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
-import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import org.slf4j.Logger;
+
 /**
- * A simple Client.
+ * A simple Client
  */
 public class Client {
 
@@ -35,7 +35,7 @@ public class Client {
   private final ServiceAmbassador serviceAmbassador = new ServiceAmbassador();
 
   long useService(int value) {
-    var result = serviceAmbassador.doRemoteFunction(value);
+    long result = serviceAmbassador.doRemoteFunction(value);
     LOGGER.info("Service result: " + result);
     return result;
   }

ambassador/src/main/java/com/iluwatar/ambassador/RemoteService.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,23 +20,20 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
-import static java.lang.Thread.sleep;
-
-import com.iluwatar.ambassador.util.RandomProvider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import static java.lang.Thread.sleep;
+
 /**
  * A remote legacy application represented by a Singleton implementation.
  */
 public class RemoteService implements RemoteServiceInterface {
-  private static final int THRESHOLD = 200;
+
   private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
   private static RemoteService service = null;
-  private final RandomProvider randomProvider;
 
   static synchronized RemoteService getRemoteService() {
     if (service == null) {
@@ -45,35 +42,24 @@ public class RemoteService implements RemoteServiceInterface {
     return service;
   }
 
-  private RemoteService() {
-    this(Math::random);
-  }
+  private RemoteService() {}
 
   /**
-   * This constructor is used for testing purposes only.
-   */
-  RemoteService(RandomProvider randomProvider) {
-    this.randomProvider = randomProvider;
-  }
-
-  /**
-   * Remote function takes a value and multiplies it by 10 taking a random amount of time. Will
-   * sometimes return -1. This imitates connectivity issues a client might have to account for.
-   *
+   * Remote function takes a value and multiplies it by 10 taking a random amount of time.
+   * Will sometimes return -1. This imitates connectivity issues a client might have to account for.
    * @param value integer value to be multiplied.
-   * @return if waitTime is less than {@link RemoteService#THRESHOLD}, it returns value * 10,
-   *     otherwise {@link RemoteServiceInterface#FAILURE}.
+   * @return if waitTime is more than 200ms, it returns value * 10, otherwise -1.
    */
   @Override
   public long doRemoteFunction(int value) {
 
-    long waitTime = (long) Math.floor(randomProvider.random() * 1000);
+    long waitTime = (long) Math.floor(Math.random() * 1000);
 
     try {
       sleep(waitTime);
     } catch (InterruptedException e) {
       LOGGER.error("Thread sleep state interrupted", e);
     }
-    return waitTime <= THRESHOLD ? value * 10 : FAILURE;
+    return waitTime >= 200 ? value * 10 : -1;
   }
 }

ambassador/src/main/java/com/iluwatar/ambassador/RemoteServiceInterface.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,14 +20,12 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
 /**
  * Interface shared by ({@link RemoteService}) and ({@link ServiceAmbassador}).
  */
 interface RemoteServiceInterface {
-  int FAILURE = -1;
-
+    
   long doRemoteFunction(int value) throws Exception;
 }

ambassador/src/main/java/com/iluwatar/ambassador/ServiceAmbassador.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,18 +20,19 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
-import static java.lang.Thread.sleep;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import static java.lang.Thread.sleep;
+
 /**
+ *
  * ServiceAmbassador provides an interface for a ({@link Client}) to access ({@link RemoteService}).
  * The interface adds logging, latency testing and usage of the service in a safe way that will not
  * add stress to the remote service when connectivity issues occur.
+ *
  */
 public class ServiceAmbassador implements RemoteServiceInterface {
 
@@ -39,8 +40,7 @@ public class ServiceAmbassador implements RemoteServiceInterface {
   private static final int RETRIES = 3;
   private static final int DELAY_MS = 3000;
 
-  ServiceAmbassador() {
-  }
+  ServiceAmbassador() {}
 
   @Override
   public long doRemoteFunction(int value) {
@@ -48,24 +48,26 @@ public class ServiceAmbassador implements RemoteServiceInterface {
   }
 
   private long checkLatency(int value) {
-    var startTime = System.currentTimeMillis();
-    var result = RemoteService.getRemoteService().doRemoteFunction(value);
-    var timeTaken = System.currentTimeMillis() - startTime;
+    long startTime = System.currentTimeMillis();
+    long result = RemoteService.getRemoteService().doRemoteFunction(value);
+    long timeTaken = System.currentTimeMillis() - startTime;
 
     LOGGER.info("Time taken (ms): " + timeTaken);
     return result;
   }
 
   private long safeCall(int value) {
-    var retries = 0;
-    var result = (long) FAILURE;
+
+    int retries = 0;
+    long result = -1;
 
     for (int i = 0; i < RETRIES; i++) {
+
       if (retries >= RETRIES) {
-        return FAILURE;
+        return -1;
       }
 
-      if ((result = checkLatency(value)) == FAILURE) {
+      if ((result = checkLatency(value)) == -1) {
         LOGGER.info("Failed to reach remote: (" + (i + 1) + ")");
         retries++;
         try {

ambassador/src/main/java/com/iluwatar/ambassador/util/RandomProvider.java

@@ -1,31 +0,0 @@
-/*
- * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-package com.iluwatar.ambassador.util;
-
-/**
- * An interface for randomness. Useful for testing purposes.
- */
-public interface RandomProvider {
-  double random();
-}

ambassador/src/test/java/com/iluwatar/ambassador/AppTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,7 +20,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
 import org.junit.jupiter.api.Test;
@@ -28,10 +27,10 @@ import org.junit.jupiter.api.Test;
 /**
  * Application test
  */
-class AppTest {
+public class AppTest {
 
   @Test
-  void test() {
+  public void test() {
     App.main(new String[]{});
   }
 }

ambassador/src/test/java/com/iluwatar/ambassador/ClientTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,23 +20,21 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 /**
  * Test for {@link Client}
  */
-class ClientTest {
+public class ClientTest {
 
   @Test
-  void test() {
-    Client client = new Client();
-    var result = client.useService(10);
+  public void test() {
 
-    assertTrue(result == 100 || result == RemoteService.FAILURE);
+    Client client = new Client();
+    long result = client.useService(10);
+
+    assert result == 100 || result == -1;
   }
 }

ambassador/src/test/java/com/iluwatar/ambassador/RemoteServiceTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,43 +20,18 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-import com.iluwatar.ambassador.util.RandomProvider;
 import org.junit.jupiter.api.Test;
 
 /**
  * Test for {@link RemoteService}
  */
-class RemoteServiceTest {
+public class RemoteServiceTest {
 
   @Test
-  void testFailedCall() {
-    var remoteService = new RemoteService(new StaticRandomProvider(0.21));
-    var result = remoteService.doRemoteFunction(10);
-    assertEquals(RemoteServiceInterface.FAILURE, result);
-  }
-
-  @Test
-  void testSuccessfulCall() {
-    var remoteService = new RemoteService(new StaticRandomProvider(0.2));
-    var result = remoteService.doRemoteFunction(10);
-    assertEquals(100, result);
-  }
-
-  private static class StaticRandomProvider implements RandomProvider {
-    private double value;
-
-    StaticRandomProvider(double value) {
-      this.value = value;
-    }
-
-    @Override
-    public double random() {
-      return value;
-    }
+  public void test() {
+    long result = RemoteService.getRemoteService().doRemoteFunction(10);
+    assert result == 100 || result == -1;
   }
 }

ambassador/src/test/java/com/iluwatar/ambassador/ServiceAmbassadorTest.java

@@ -1,6 +1,6 @@
-/*
+/**
  * The MIT License
- * Copyright © 2014-2019 Ilkka Seppälä
+ * Copyright (c) 2014-2016 Ilkka Seppälä
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -20,21 +20,18 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-
 package com.iluwatar.ambassador;
 
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 /**
  * Test for {@link ServiceAmbassador}
  */
-class ServiceAmbassadorTest {
+public class ServiceAmbassadorTest {
 
   @Test
-  void test() {
+  public void test() {
     long result = new ServiceAmbassador().doRemoteFunction(10);
-    assertTrue(result == 100 || result == RemoteServiceInterface.FAILURE);
+    assert result == 100 || result == -1;
   }
 }

api-gateway/api-gateway-service/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
+    Copyright (c) 2014-2016 Ilkka Seppälä
 
     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
@@ -29,11 +29,20 @@
   <parent>
     <artifactId>api-gateway</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.21.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>api-gateway-service</artifactId>
   <packaging>jar</packaging>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-dependencies</artifactId>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
   <dependencies>
     <dependency>
       <groupId>org.springframework</groupId>
@@ -43,6 +52,11 @@
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-web</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-engine</artifactId>
@@ -53,6 +67,10 @@
       <artifactId>mockito-core</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.apache.httpcomponents</groupId>
+      <artifactId>httpclient</artifactId>
+    </dependency>
   </dependencies>
 
   <build>
@@ -60,6 +78,7 @@
       <plugin>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-maven-plugin</artifactId>
+        <version>${spring-boot.version}</version>
         <executions>
           <execution>
             <goals>
@@ -70,4 +89,4 @@
       </plugin>
     </plugins>
   </build>
-</project>
+</project>