Adding composite specification (Issue#1093) (#1094)

* Resolution proposition to Issue#1055 (UML diagram left to do)

* Deciding not to modify the UML diagram for now

* Resolution proposition to Issue#1093

* Code reformatting

.github/FUNDING.yml

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

.gitignore

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

.sonarcloud.properties

@@ -1,15 +0,0 @@
-# Path to sources
-#sonar.sources=.
-#sonar.exclusions=
-#sonar.inclusions=
-
-# Path to tests
-#sonar.tests=
-#sonar.test.exclusions=
-#sonar.test.inclusions=
-
-# Source encoding
-#sonar.sourceEncoding=UTF-8
-
-# Exclusions for copy-paste detection
-#sonar.cpd.exclusions=

.travis.yml

@@ -1,31 +1,29 @@
 language: java
-dist: trusty   # Xenial build environment won't allow installation of Java 8
+dist: bionic
 jdk:
-- oraclejdk8
+- openjdk11
+sudo: required
 
 env:
   global:
-  - GH_REF: github.com/iluwatar/java-design-patterns.git
+  - secure: "DCpazS3nkLnter3sguXEAS2fC/1ZWNfM+XLyif9MfNFxlZdpni2vCD/jA0Rdpga8puQWHNVLyAec+RPFH/2qSmJ1c1UTV5MaLv8tPqwUX0VFA+1I6XoSv6oX4ldHTBWHEWqQHkRFOLoil0h0edc0tTOWQwXF8U+DLAB+HkRb4gw="
-  - 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
 
-# default install command is just "mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V"
+services:
-install:
+- xvfb
-- mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V -e
+
+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'
 
 after_success:
-- mvn clean org.jacoco:jacoco-maven-plugin:prepare-agent package sonar:sonar -Dsonar.host.url=https://sonarcloud.io -Dsonar.login=$SONAR_TOKEN
+- bash update-website.sh
-- bash update-ghpages.sh
-
-# use latest java version available instead of travis default
-addons:
-  apt:
-    packages:
-      - oracle-java8-installer
 
 notifications:
   email:
@@ -36,5 +34,3 @@ 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

@@ -1,13 +0,0 @@
-# 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 
-* business-delegate/target/site/jacoco/index.html 
-
-

README.md

@@ -17,14 +17,21 @@ 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 which cause major
+Reusing design patterns help prevent subtle issues that 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
-Programming/Software Design Principles.
+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
@@ -35,12 +42,17 @@ 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 (c) 2014-2016 Ilkka Seppälä
+    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
@@ -29,7 +29,7 @@
     <parent>
         <artifactId>java-design-patterns</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.21.0</version>
+        <version>1.22.0-SNAPSHOT</version>
     </parent>
     <artifactId>abstract-document</artifactId>
     <dependencies>

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,17 +20,18 @@
  * 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 {
 
@@ -54,16 +55,21 @@ public abstract class AbstractDocument implements Document {
 
   @Override
   public <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor) {
-    Optional<List<Map<String, Object>>> any = Stream.of(get(key)).filter(Objects::nonNull)
+    return Stream.ofNullable(get(key))
-        .map(el -> (List<Map<String, Object>>) el).findAny();
+        .filter(Objects::nonNull)
-    return any.map(maps -> maps.stream().map(constructor)).orElseGet(Stream::empty);
+        .map(el -> (List<Map<String, Object>>) el)
+        .findAny()
+        .stream()
+        .flatMap(Collection::stream)
+        .map(constructor);
   }
 
   @Override
   public String toString() {
-    StringBuilder builder = new StringBuilder();
+    var builder = new StringBuilder();
     builder.append(getClass().getName()).append("[");
-    properties.forEach((key, value) -> builder.append("[").append(key).append(" : ").append(value).append("]"));
+    properties.forEach((key, value) -> builder.append("[").append(key).append(" : ").append(value)
+        .append("]"));
     builder.append("]");
     return builder.toString();
   }

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,65 +20,64 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.abstractdocument;
 
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.iluwatar.abstractdocument.domain.Car;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.List;
+import java.util.Map;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
- * The Abstract Document pattern enables handling additional, non-static
+ * The Abstract Document pattern enables handling additional, non-static properties. This pattern
- * properties. This pattern uses concept of traits to enable type safety and
+ * uses concept of traits to enable type safety and separate properties of different classes into
- * separate properties of different classes into set of interfaces.
+ * set of interfaces.
- * <p>
+ *
- * <p>
+ * <p>In Abstract Document pattern,({@link AbstractDocument}) fully implements {@link Document})
- * In Abstract Document pattern,({@link AbstractDocument}) fully implements
+ * interface. Traits are then defined to enable access to properties in usual, static way.
- * {@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");
 
-    Map<String, Object> carProperties = new HashMap<>();
+    var wheelProperties = Map.of(
-    carProperties.put(Property.MODEL.toString(), "300SL");
+        Property.TYPE.toString(), "wheel",
-    carProperties.put(Property.PRICE.toString(), 10000L);
+        Property.MODEL.toString(), "15C",
+        Property.PRICE.toString(), 100L);
 
-    Map<String, Object> wheelProperties = new HashMap<>();
+    var doorProperties = Map.of(
-    wheelProperties.put(Property.TYPE.toString(), "wheel");
+        Property.TYPE.toString(), "door",
-    wheelProperties.put(Property.MODEL.toString(), "15C");
+        Property.MODEL.toString(), "Lambo",
-    wheelProperties.put(Property.PRICE.toString(), 100L);
+        Property.PRICE.toString(), 300L);
 
-    Map<String, Object> doorProperties = new HashMap<>();
+    var carProperties = Map.of(
-    doorProperties.put(Property.TYPE.toString(), "door");
+        Property.MODEL.toString(), "300SL",
-    doorProperties.put(Property.MODEL.toString(), "Lambo");
+        Property.PRICE.toString(), 10000L,
-    doorProperties.put(Property.PRICE.toString(), 300L);
+        Property.PARTS.toString(), List.of(wheelProperties, doorProperties));
 
-    carProperties.put(Property.PARTS.toString(), Arrays.asList(wheelProperties, doorProperties));
+    var car = new Car(carProperties);
-
-    Car car = new Car(carProperties);
 
     LOGGER.info("Here is our car:");
-    LOGGER.info("-> model: {}", car.getModel().get());
+    LOGGER.info("-> model: {}", car.getModel().orElseThrow());
-    LOGGER.info("-> price: {}", car.getPrice().get());
+    LOGGER.info("-> price: {}", car.getPrice().orElseThrow());
     LOGGER.info("-> parts: ");
-    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}", p.getType().get(), p.getModel().get(), p.getPrice().get()));
+    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}",
+        p.getType().orElse(null),
+        p.getModel().orElse(null),
+        p.getPrice().orElse(null))
+    );
   }
 
   /**
-   * 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * 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;
@@ -27,12 +28,12 @@ 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
@@ -41,7 +42,7 @@ 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
@@ -49,7 +50,7 @@ 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,15 +20,15 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-package com.iluwatar.abstractdocument.domain;
 
-import java.util.Optional;
+package com.iluwatar.abstractdocument.domain;
 
 import com.iluwatar.abstractdocument.Document;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.Optional;
 
 /**
- * HasModel trait for static access to 'model' property
+ * HasModel trait for static access to 'model' property.
  */
 public interface HasModel extends Document {
 

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,15 +20,15 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-package com.iluwatar.abstractdocument.domain;
 
-import java.util.stream.Stream;
+package com.iluwatar.abstractdocument.domain;
 
 import com.iluwatar.abstractdocument.Document;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.stream.Stream;
 
 /**
- * HasParts trait for static access to 'parts' property
+ * HasParts trait for static access to 'parts' property.
  */
 public interface HasParts extends Document {
 

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,15 +20,15 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-package com.iluwatar.abstractdocument.domain;
 
-import java.util.Optional;
+package com.iluwatar.abstractdocument.domain;
 
 import com.iluwatar.abstractdocument.Document;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.Optional;
 
 /**
- * HasPrice trait for static access to 'price' property
+ * HasPrice trait for static access to 'price' property.
  */
 public interface HasPrice extends Document {
 

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,15 +20,15 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-package com.iluwatar.abstractdocument.domain;
 
-import java.util.Optional;
+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 {
 

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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.
- * Enum To Describe Property type
- *
  */
 public enum Property {
 

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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 +20,18 @@
  * 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
  */
@@ -59,29 +57,26 @@ public class AbstractDocumentTest {
 
   @Test
   public void shouldRetrieveChildren() {
-    Map<String, Object> child1 = new HashMap<>();
+    var children = List.of(Map.of(), Map.of());
-    Map<String, Object> child2 = new HashMap<>();
-    List<Map<String, Object>> children = Arrays.asList(child1, child2);
 
     document.put(KEY, children);
 
-    Stream<DocumentImplementation> childrenStream = document.children(KEY, DocumentImplementation::new);
+    var childrenStream = document.children(KEY, DocumentImplementation::new);
     assertNotNull(children);
     assertEquals(2, childrenStream.count());
   }
 
   @Test
   public void shouldRetrieveEmptyStreamForNonExistingChildren() {
-    Stream<DocumentImplementation> children = document.children(KEY, DocumentImplementation::new);
+    var children = document.children(KEY, DocumentImplementation::new);
     assertNotNull(children);
     assertEquals(0, children.count());
   }
 
   @Test
   public void shouldIncludePropsInToString() {
-    Map<String, Object> props = new HashMap<>();
+    var props = Map.of(KEY, (Object) VALUE);
-    props.put(KEY, VALUE);
+    var document = new DocumentImplementation(props);
-    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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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 +20,17 @@
  * 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 java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.junit.jupiter.api.Test;
-
 import com.iluwatar.abstractdocument.domain.Car;
 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;
 
 /**
  * Test for Part and Car
@@ -48,27 +46,27 @@ public class DomainTest {
 
   @Test
   public void shouldConstructPart() {
-    Map<String, Object> partProperties = new HashMap<>();
+    var partProperties = Map.of(
-    partProperties.put(Property.TYPE.toString(), TEST_PART_TYPE);
+        Property.TYPE.toString(), TEST_PART_TYPE,
-    partProperties.put(Property.MODEL.toString(), TEST_PART_MODEL);
+        Property.MODEL.toString(), TEST_PART_MODEL,
-    partProperties.put(Property.PRICE.toString(), TEST_PART_PRICE);
+        Property.PRICE.toString(), (Object) TEST_PART_PRICE
-    Part part = new Part(partProperties);
+    );
-
+    var part = new Part(partProperties);
-    assertEquals(TEST_PART_TYPE, part.getType().get());
+    assertEquals(TEST_PART_TYPE, part.getType().orElseThrow());
-    assertEquals(TEST_PART_MODEL, part.getModel().get());
+    assertEquals(TEST_PART_MODEL, part.getModel().orElseThrow());
-    assertEquals(TEST_PART_PRICE, part.getPrice().get());
+    assertEquals(TEST_PART_PRICE, part.getPrice().orElseThrow());
   }
 
   @Test
   public void shouldConstructCar() {
-    Map<String, Object> carProperties = new HashMap<>();
+    var carProperties = Map.of(
-    carProperties.put(Property.MODEL.toString(), TEST_CAR_MODEL);
+        Property.MODEL.toString(), TEST_CAR_MODEL,
-    carProperties.put(Property.PRICE.toString(), TEST_CAR_PRICE);
+        Property.PRICE.toString(), TEST_CAR_PRICE,
-    carProperties.put(Property.PARTS.toString(), Arrays.asList(new HashMap<>(), new HashMap<>()));
+        Property.PARTS.toString(), List.of(Map.of(), Map.of())
-    Car car = new Car(carProperties);
+    );
-
+    var car = new Car(carProperties);
-    assertEquals(TEST_CAR_MODEL, car.getModel().get());
+    assertEquals(TEST_CAR_MODEL, car.getModel().orElseThrow());
-    assertEquals(TEST_CAR_PRICE, car.getPrice().get());
+    assertEquals(TEST_CAR_PRICE, car.getPrice().orElseThrow());
     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
-KingdomFactory factory = new ElfKingdomFactory();
+var factory = new ElfKingdomFactory();
-Castle castle = factory.createCastle();
+var castle = factory.createCastle();
-King king = factory.createKing();
+var king = factory.createKing();
-Army army = factory.createArmy();
+var 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) {
-  App app = new App();
+  var app = new App();
 
   LOGGER.info("Elf Kingdom");
   app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));
@@ -169,24 +169,25 @@ 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

@@ -1,190 +0,0 @@
-<!--
-
-    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://remarkjs.com/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 (c) 2014-2016 Ilkka Seppälä
+    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
@@ -29,7 +29,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.21.0</version>
+    <version>1.22.0-SNAPSHOT</version>
   </parent>
   <artifactId>abstract-factory</artifactId>
   <dependencies>

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,27 +20,26 @@
  * 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
- * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that have a common theme
+ * have a common theme without specifying their concrete classes. In normal usage, the client
- * without specifying their concrete classes. In normal usage, the client software creates a concrete implementation of
+ * software creates a concrete implementation of the abstract factory and then uses the generic
- * the abstract factory and then uses the generic interface of the factory to create the concrete objects that are part
+ * interface of the factory to create the concrete objects that are part of the theme. The client
- * of the theme. The client does not know (or care) which concrete objects it gets from each of these internal
+ * does not know (or care) which concrete objects it gets from each of these internal factories,
- * factories, since it uses only the generic interfaces of their products. This pattern separates the details of
+ * since it uses only the generic interfaces of their products. This pattern separates the details
- * implementation of a set of objects from their general usage and relies on object composition, as object creation is
+ * of implementation of a set of objects from their general usage and relies on object composition,
- * implemented in methods exposed in the factory interface.
+ * 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 (
+ * <p>The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory})
- * {@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses both concrete implementations to create a
+ * and its implementations ( {@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses
- * king, a castle and an army.
+ * both concrete implementations to create a king, a castle and an army.
- * 
  */
 public class App {
 
@@ -51,14 +50,14 @@ 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();
   }
@@ -70,7 +69,7 @@ public class App {
   private void setKing(final King king) {
     this.king = king;
   }
-  
+
   Castle getCastle(final KingdomFactory factory) {
     return factory.createCastle();
   }
@@ -82,7 +81,7 @@ public class App {
   private void setCastle(final Castle castle) {
     this.castle = castle;
   }
-  
+
   Army getArmy(final KingdomFactory factory) {
     return factory.createArmy();
   }
@@ -124,13 +123,12 @@ public class App {
 
   /**
    * Program entry point.
-   * 
+   *
-   * @param args
+   * @param args command line args
-   *          command line args
    */
   public static void main(String[] args) {
 
-    App app = new App();
+    var 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 {
 

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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 {
 

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * 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;
@@ -27,12 +28,11 @@ 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 King elfKing = app.getKing(elfFactory);
+    final var elfKing = app.getKing(elfFactory);
     assertTrue(elfKing instanceof ElfKing);
     assertEquals(ElfKing.DESCRIPTION, elfKing.getDescription());
-    final King orcKing = app.getKing(orcFactory);
+    final var orcKing = app.getKing(orcFactory);
     assertTrue(orcKing instanceof OrcKing);
     assertEquals(OrcKing.DESCRIPTION, orcKing.getDescription());
   }
 
   @Test
   public void castle() {
-    final Castle elfCastle = app.getCastle(elfFactory);
+    final var elfCastle = app.getCastle(elfFactory);
     assertTrue(elfCastle instanceof ElfCastle);
     assertEquals(ElfCastle.DESCRIPTION, elfCastle.getDescription());
-    final Castle orcCastle = app.getCastle(orcFactory);
+    final var orcCastle = app.getCastle(orcFactory);
     assertTrue(orcCastle instanceof OrcCastle);
     assertEquals(OrcCastle.DESCRIPTION, orcCastle.getDescription());
   }
 
   @Test
   public void army() {
-    final Army elfArmy = app.getArmy(elfFactory);
+    final var elfArmy = app.getArmy(elfFactory);
     assertTrue(elfArmy instanceof ElfArmy);
     assertEquals(ElfArmy.DESCRIPTION, elfArmy.getDescription());
-    final Army orcArmy = app.getArmy(orcFactory);
+    final var 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 King king = app.getKing();
+    final var king = app.getKing();
-    final Castle castle = app.getCastle();
+    final var castle = app.getCastle();
-    final Army army = app.getArmy();
+    final var 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 King king = app.getKing();
+    final var king = app.getKing();
-    final Castle castle = app.getCastle();
+    final var castle = app.getCastle();
-    final Army army = app.getArmy();
+    final var 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,19 +20,17 @@
  * 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() throws IOException {
+  public void test() {
-    String[] args = {};
+    App.main(new String[]{});
-    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/README.md)
+* [Visitor Pattern](../visitor/)
 
 ## 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 (c) 2014 Ilkka Seppälä
+    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
@@ -30,7 +30,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.21.0</version>
+		<version>1.22.0-SNAPSHOT</version>
 	</parent>
 	
 	<artifactId>acyclic-visitor</artifactId>

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,13 @@
  * 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
+ * All ModemVisitor interface extends all visitor interfaces. This interface provides ease of use
- * provides ease of use when a visitor needs to visit all modem types.
+ * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,33 +20,32 @@
  * 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 
+ * The Acyclic Visitor pattern allows new functions to be added to existing class hierarchies
- * hierarchies without affecting those hierarchies, and without creating the dependency 
+ * without affecting those hierarchies, and without creating the dependency cycles that are inherent
- * cycles that are inherent to the GoF Visitor pattern, by making the Visitor base class 
+ * to the GoF Visitor pattern, by making the Visitor base class degenerate
- * degenerate
+ *
- * <p>
+ * <p>In this example the visitor base class is {@link ModemVisitor}. The base class of the visited
- * In this example the visitor base class is {@link ModemVisitor}. The base class of the 
+ * hierarchy is {@link Modem} and has two children {@link Hayes} and {@link Zoom} each one having
- * visited hierarchy is {@link Modem} and has two children {@link Hayes} and {@link Zoom} 
+ * its own visitor interface {@link HayesVisitor} and {@link ZoomVisitor} respectively. {@link
- * each one having its own visitor interface {@link HayesVisitor} and {@link ZoomVisitor} 
+ * ConfigureForUnixVisitor} and {@link ConfigureForDosVisitor} implement each derivative's visit
- * respectively. {@link ConfigureForUnixVisitor} and {@link ConfigureForDosVisitor} 
+ * method only if it is required
- * 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) {
-  public static void main(String[] args) {  
+    var conUnix = new ConfigureForUnixVisitor();
-    ConfigureForUnixVisitor conUnix = new ConfigureForUnixVisitor();
+    var conDos = new ConfigureForDosVisitor();
-    ConfigureForDosVisitor conDos = new ConfigureForDosVisitor();
+
-    
+    var zoom = new Zoom();
-    Zoom zoom = new Zoom();
+    var hayes = new Hayes();
-    Hayes hayes = new Hayes();
+
-    
     hayes.accept(conDos); // Hayes modem with Dos configurator
     zoom.accept(conDos); // Zoom modem with Dos configurator
     hayes.accept(conUnix); // Hayes modem with Unix configurator

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,14 +20,15 @@
  * 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 
+ * ConfigureForDosVisitor class implements both zoom's and  hayes' visit method for Dos
- * for Dos manufacturer
+ * manufacturer.
  */
 public class ConfigureForDosVisitor implements AllModemVisitor {
 

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,15 +20,15 @@
  * 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 
+ * ConfigureForUnixVisitor class implements zoom's visit method for Unix manufacturer, unlike
- * manufacturer, unlike traditional visitor pattern, this class may selectively implement
+ * traditional visitor pattern, this class may selectively implement visit for other modems.
- * visit for other modems.
  */
 public class ConfigureForUnixVisitor implements ZoomVisitor {
 

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,20 +20,21 @@
  * 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) {
@@ -44,10 +45,9 @@ public class Hayes extends Modem {
     }
 
   }
-  
+
   /**
-   * Hayes' modem's toString
+   * Hayes' modem's toString method.
-   * method
    */
   @Override
   public String toString() {

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,10 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,10 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -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
+ * ModemVisitor interface does not contain any visit methods so that it does not depend on the
- * depend on the visited hierarchy. Each derivative's visit method is declared in 
+ * visited hierarchy. Each derivative's visit method is declared in its own visitor interface
- * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -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
+   * Zoom modem's toString method.
-   * method
    */
   @Override
   public String toString() {

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,10 +20,11 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,20 +20,18 @@
  * 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() {
-    String[] args = {};
+    App.main(new String[]{});
-    App.main(args);  
   }
 }

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,22 +20,15 @@
  * 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;
 
@@ -44,28 +37,30 @@ import uk.org.lidalia.slf4jtest.TestLoggerFactory;
  */
 public class ConfigureForDosVisitorTest {
 
-  TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class);
+  private TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class);
   
   @Test
   public void testVisitForZoom() {    
-    ConfigureForDosVisitor conDos = new ConfigureForDosVisitor();
+    var conDos = new ConfigureForDosVisitor();
-    Zoom zoom = new Zoom();
+    var zoom = new Zoom();
     
     conDos.visit(zoom);
     
-    assertThat(logger.getLoggingEvents()).extracting("level", "message").contains(
+    assertThat(logger.getLoggingEvents())
-        tuple(INFO, zoom + " used with Dos configurator."));
+        .extracting("level", "message")
+        .contains(tuple(INFO, zoom + " used with Dos configurator."));
   }
   
   @Test
   public void testVisitForHayes() {
-    ConfigureForDosVisitor conDos = new ConfigureForDosVisitor();
+    var conDos = new ConfigureForDosVisitor();
-    Hayes hayes = new Hayes();
+    var hayes = new Hayes();
     
     conDos.visit(hayes);
     
-    assertThat(logger.getLoggingEvents()).extracting("level", "message").contains(
+    assertThat(logger.getLoggingEvents())
-        tuple(INFO, hayes + " used with Dos configurator."));
+        .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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * 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;
@@ -46,12 +47,13 @@ public class ConfigureForUnixVisitorTest {
   
   @Test
   public void testVisitForZoom() {
-    ConfigureForUnixVisitor conUnix = new ConfigureForUnixVisitor();
+    var conUnix = new ConfigureForUnixVisitor();
-    Zoom zoom = new Zoom();
+    var zoom = new Zoom();
     
     conUnix.visit(zoom);
     
-    assertThat(LOGGER.getLoggingEvents()).extracting("level", "message").contains(
+    assertThat(LOGGER.getLoggingEvents())
-        tuple(INFO, zoom + " used with Unix configurator."));
+        .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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * 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;
@@ -29,11 +30,6 @@ 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
  */
@@ -41,8 +37,8 @@ public class HayesTest {
 
   @Test
   public void testAcceptForDos() {  
-    Hayes hayes = new Hayes();
+    var hayes = new Hayes();
-    ConfigureForDosVisitor mockVisitor = mock(ConfigureForDosVisitor.class);
+    var mockVisitor = mock(ConfigureForDosVisitor.class);
     
     hayes.accept(mockVisitor);
     verify((HayesVisitor)mockVisitor).visit(eq(hayes));
@@ -50,8 +46,8 @@ public class HayesTest {
   
   @Test
   public void testAcceptForUnix() {    
-    Hayes hayes = new Hayes();
+    var hayes = new Hayes();
-    ConfigureForUnixVisitor mockVisitor = mock(ConfigureForUnixVisitor.class);
+    var 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.acyclicvisitor;
 
 
@@ -29,11 +30,6 @@ 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
  */
@@ -41,8 +37,8 @@ public class ZoomTest {
   
   @Test
   public void testAcceptForDos() {  
-    Zoom zoom = new Zoom();
+    var zoom = new Zoom();
-    ConfigureForDosVisitor mockVisitor = mock(ConfigureForDosVisitor.class);
+    var mockVisitor = mock(ConfigureForDosVisitor.class);
     
     zoom.accept(mockVisitor);
     verify((ZoomVisitor)mockVisitor).visit(eq(zoom));
@@ -50,8 +46,8 @@ public class ZoomTest {
   
   @Test
   public void testAcceptForUnix() {
-    Zoom zoom = new Zoom();
+    var zoom = new Zoom();
-    ConfigureForUnixVisitor mockVisitor = mock(ConfigureForUnixVisitor.class);
+    var mockVisitor = mock(ConfigureForUnixVisitor.class);
     
     zoom.accept(mockVisitor);
     verify((ZoomVisitor)mockVisitor).visit(eq(zoom));

adapter/README.md

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

adapter/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright (c) 2014-2016 Ilkka Seppälä
+    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
@@ -29,7 +29,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.21.0</version>
+    <version>1.22.0-SNAPSHOT</version>
   </parent>
   <artifactId>adapter</artifactId>
   <dependencies>

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.adapter;
 
 /**
@@ -28,33 +29,33 @@ 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>
+ * <p>There are two variations of the Adapter pattern: The class adapter implements the adaptee's
- * 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>
+ * <p>The Adapter ({@link FishingBoatAdapter}) converts the interface of the adaptee class ({@link
- * The Adapter ({@link FishingBoatAdapter}) converts the interface of the adaptee class (
+ * FishingBoat}) into a suitable one expected by the client ({@link RowingBoat}).
- * {@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 class App {
+public final class App {
+
+  private App() {
+  }
 
   /**
    * Program entry point.
    *
    * @param args command line args
    */
-  public static void main(String[] 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
+    // The captain can only operate rowing boats but with adapter he is able to
-    Captain captain = new Captain(new FishingBoatAdapter());
+    // use fishing boats as well
+    var captain = new Captain(new FishingBoatAdapter());
     captain.row();
   }
 }

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,27 +20,28 @@
  * 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>
+ * The Captain uses {@link RowingBoat} to sail. <br> This is the client in the pattern.
- * This is the client in the pattern.
  */
-public class Captain {
+public final class Captain {
 
   private RowingBoat rowingBoat;
 
-  public Captain() {}
+  public Captain() {
-
-  public Captain(RowingBoat rowingBoat) {
-    this.rowingBoat = rowingBoat;
   }
 
-  public void setRowingBoat(RowingBoat rowingBoat) {
+  public Captain(final RowingBoat boat) {
-    this.rowingBoat = rowingBoat;
+    this.rowingBoat = boat;
   }
 
-  public void row() {
+  void setRowingBoat(final RowingBoat boat) {
+    this.rowingBoat = boat;
+  }
+
+  void row() {
     rowingBoat.row();
   }
 

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -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
- * Device class (adaptee in the pattern). We want to reuse this class.
+ * sailing.
- * Fishing boat moves by sailing.
- *
  */
-public class FishingBoat {
+final class FishingBoat {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoat.class);
+  private static final Logger LOGGER = getLogger(FishingBoat.class);
 
-  public void sail() {
+  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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,13 +20,12 @@
  * 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 {
 
@@ -36,8 +35,7 @@ public class FishingBoatAdapter implements RowingBoat {
     boat = new FishingBoat();
   }
 
-  @Override
+  public final void row() {
-  public void row() {
     boat.sail();
   }
 }

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,12 +20,11 @@
  * 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>
+ * The interface expected by the client.<br> A rowing boat is rowed to move.
- * A rowing boat is rowed to move.
- *
  */
 public interface RowingBoat {
 

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

@@ -0,0 +1,24 @@
+/*
+ * 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,20 +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.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 {
 
@@ -50,29 +49,29 @@ public class AdapterPatternTest {
   public void setup() {
     beans = new HashMap<>();
 
-    FishingBoatAdapter fishingBoatAdapter = spy(new FishingBoatAdapter());
+    var fishingBoatAdapter = spy(new FishingBoatAdapter());
     beans.put(FISHING_BEAN, fishingBoatAdapter);
 
-    Captain captain = new Captain();
+    var 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
+   * This test asserts that when we use the row() method on a captain bean(client), it is internally
-   * internally calling sail method on the fishing boat object. The Adapter ({@link FishingBoatAdapter}
+   * 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
+   * converts the interface of the target class ( {@link FishingBoat}) into a suitable one expected
-   * expected by the client ({@link Captain} ).
+   * by the client ({@link Captain} ).
    */
   @Test
   public void testAdapter() {
-    Captain captain = (Captain) beans.get(ROWING_BEAN);
+    var captain = (Captain) beans.get(ROWING_BEAN);
 
     // when captain moves
     captain.row();
 
     // the captain internally calls the battleship object to move
-    RowingBoat adapter = (RowingBoat) beans.get(FISHING_BEAN);
+    var 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,19 +20,17 @@
  * 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() throws IOException {
+  public void test() {
-    String[] args = {};
+    App.main(new String[]{});
-    App.main(args);
   }
 }

aggregator-microservices/aggregator-service/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright (c) 2014-2016 Ilkka Seppälä
+    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
@@ -29,21 +29,11 @@
     <parent>
         <artifactId>aggregator-microservices</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.21.0</version>
+        <version>1.22.0-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>
@@ -63,10 +53,6 @@
             <artifactId>mockito-core</artifactId>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>org.apache.httpcomponents</groupId>
-            <artifactId>httpclient</artifactId>
-        </dependency>
     </dependencies>
 
     <build>
@@ -74,7 +60,6 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
-                <version>${spring-boot.version}</version>
                 <executions>
                     <execution>
                         <goals>

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,16 +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.web.bind.annotation.RequestMapping;
+import static java.util.Objects.requireNonNullElse;
-import org.springframework.web.bind.annotation.RestController;
 
 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;
 
 /**
- * The aggregator aggregates calls on various micro-services, collects
+ * The aggregator aggregates calls on various micro-services, collects data and further publishes
- * data and further publishes them under a REST endpoint.
+ * them under a REST endpoint.
  */
 @RestController
 public class Aggregator {
@@ -47,11 +50,19 @@ public class Aggregator {
    *
    * @return a Product.
    */
-  @RequestMapping("/product")
+  @RequestMapping(path = "/product", method = RequestMethod.GET)
   public Product getProduct() {
-    Product product = new Product();
+
-    product.setTitle(informationClient.getProductTitle());
+    var product = new Product();
-    product.setProductInventories(inventoryClient.getProductInventories());
+    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));
+
     return product;
   }
 

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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 +20,20 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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 +20,18 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.aggregator.microservices;
 
-import org.apache.http.client.methods.CloseableHttpResponse;
+import java.io.IOException;
-import org.apache.http.client.methods.HttpGet;
+import java.net.URI;
-import org.apache.http.impl.client.CloseableHttpClient;
+import java.net.http.HttpClient;
-import org.apache.http.impl.client.HttpClients;
+import java.net.http.HttpRequest;
-import org.apache.http.util.EntityUtils;
+import java.net.http.HttpResponse;
 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.
  */
@@ -43,15 +42,19 @@ public class ProductInformationClientImpl implements ProductInformationClient {
 
   @Override
   public String getProductTitle() {
-    String response = null;
+    var request = HttpRequest.newBuilder()
-    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+        .GET()
-      HttpGet httpGet = new HttpGet("http://localhost:51515/information");
+        .uri(URI.create("http://localhost:51515/information"))
-      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
+        .build();
-        response = EntityUtils.toString(httpResponse.getEntity());
+    var client = HttpClient.newHttpClient();
-      }
+    try {
-    } catch (IOException e) {
+      var httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString());
-      LOGGER.error("Exception caught.", e);
+      return httpResponse.body();
+    } catch (IOException ioe) {
+      LOGGER.error("IOException Occurred", ioe);
+    } catch (InterruptedException ie) {
+      LOGGER.error("InterruptedException Occurred", ie);
     }
-    return response;
+    return null;
   }
 }

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.aggregator.microservices;
 
 /**
@@ -27,5 +28,5 @@ package com.iluwatar.aggregator.microservices;
  */
 public interface ProductInventoryClient {
 
-  int getProductInventories();
+  Integer getProductInventories();
 }

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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 +20,18 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.aggregator.microservices;
 
-import org.apache.http.client.methods.CloseableHttpResponse;
+import java.io.IOException;
-import org.apache.http.client.methods.HttpGet;
+import java.net.URI;
-import org.apache.http.impl.client.CloseableHttpClient;
+import java.net.http.HttpClient;
-import org.apache.http.impl.client.HttpClients;
+import java.net.http.HttpRequest;
-import org.apache.http.util.EntityUtils;
+import java.net.http.HttpResponse;
 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.
  */
@@ -42,16 +41,26 @@ public class ProductInventoryClientImpl implements ProductInventoryClient {
   private static final Logger LOGGER = LoggerFactory.getLogger(ProductInventoryClientImpl.class);
 
   @Override
-  public int getProductInventories() {
+  public Integer getProductInventories() {
-    String response = "0";
+    var response = "";
-    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+
-      HttpGet httpGet = new HttpGet("http://localhost:51516/inventories");
+    var request = HttpRequest.newBuilder()
-      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
+        .GET()
-        response = EntityUtils.toString(httpResponse.getEntity());
+        .uri(URI.create("http://localhost:51516/inventories"))
-      }
+        .build();
-    } catch (IOException e) {
+    var client = HttpClient.newHttpClient();
-      LOGGER.error("Exception caught.", e);
+    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);
     }
-    return Integer.parseInt(response);
   }
 }

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

@@ -1,6 +1,6 @@
 #
 # The MIT License
-# Copyright (c) 2014-2016 Ilkka Seppälä
+# 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
@@ -20,5 +20,4 @@
 # 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,17 +20,18 @@
  * 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
  */
@@ -55,13 +56,13 @@ public class AggregatorTest {
    */
   @Test
   public void testGetProduct() {
-    String title = "The Product Title.";
+    var title = "The Product Title.";
-    int inventories = 5;
+    var inventories = 5;
 
     when(informationClient.getProductTitle()).thenReturn(title);
     when(inventoryClient.getProductInventories()).thenReturn(inventories);
 
-    Product testProduct = aggregator.getProduct();
+    var 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 (c) 2014-2016 Ilkka Seppälä
+    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
@@ -29,21 +29,13 @@
     <parent>
         <artifactId>aggregator-microservices</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.21.0</version>
+        <version>1.22.0-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>
@@ -65,7 +57,6 @@
             <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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * 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;
@@ -27,7 +28,7 @@ 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 (c) 2014-2016 Ilkka Seppälä
+# 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
@@ -20,5 +20,4 @@
 # 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,12 +20,13 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.information.microservice;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Test for Information Rest Controller
  */
@@ -33,10 +34,8 @@ public class InformationControllerTest {
 
   @Test
   public void shouldGetProductTitle() {
-    InformationController infoController = new InformationController();
+    var infoController = new InformationController();
-
+    var title = infoController.getProductTitle();
-    String title = infoController.getProductTitle();
-
     assertEquals("The Product Title.", title);
   }
 

aggregator-microservices/inventory-microservice/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright (c) 2014-2016 Ilkka Seppälä
+    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
@@ -29,21 +29,12 @@
     <parent>
         <artifactId>aggregator-microservices</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.21.0</version>
+        <version>1.22.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
-
     <artifactId>inventory-microservice</artifactId>
-    <packaging>jar</packaging>
 
-    <dependencyManagement>
+    <packaging>jar</packaging>
-        <dependencies>
-            <dependency>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-dependencies</artifactId>
-            </dependency>
-        </dependencies>
-    </dependencyManagement>
     <dependencies>
         <dependency>
             <groupId>org.springframework</groupId>
@@ -65,7 +56,6 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
-                <version>${spring-boot.version}</version>
                 <executions>
                     <execution>
                         <goals>

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

@@ -1,17 +1,17 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,6 +20,7 @@
  * 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;
@@ -27,7 +28,7 @@ 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 (c) 2014-2016 Ilkka Seppälä
+# 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
@@ -20,5 +20,4 @@
 # 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 (c) 2014-2016 Ilkka Seppälä
+ * Copyright © 2014-2019 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
@@ -20,22 +20,21 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.inventory.microservice;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Test Inventory Rest Controller
  */
 public class InventoryControllerTest {
   @Test
   public void testGetProductInventories() {
-    InventoryController inventoryController = new InventoryController();
+    var inventoryController = new InventoryController();
-
+    var numberOfInventories = inventoryController.getProductInventories();
-    int numberOfInventories = inventoryController.getProductInventories();
-
     assertEquals(5, numberOfInventories);
   }
 }

aggregator-microservices/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright (c) 2014-2016 Ilkka Seppälä
+    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
@@ -29,7 +29,7 @@
     <parent>
         <artifactId>java-design-patterns</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.21.0</version>
+        <version>1.22.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
     <artifactId>aggregator-microservices</artifactId>

ambassador/README.md

@@ -42,7 +42,7 @@ A remote services represented as a singleton.
 ```java
 public class RemoteService implements RemoteServiceInterface {
 
-		private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
     private static RemoteService service = null;
 
     static synchronized RemoteService getRemoteService() {
@@ -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;
     }
 }
@@ -74,53 +74,50 @@ 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 Logger LOGGER = LoggerFactory.getLogger(ServiceAmbassador.class);
-    private static final int RETRIES = 3;
+  private static final int RETRIES = 3;
-    private static final int DELAY_MS = 3000;
+  private static final int DELAY_MS = 3000;
 
-    ServiceAmbassador() {}
+  ServiceAmbassador() {
+  }
 
-    @Override
+  @Override
-    public long doRemoteFunction(int value) {
+  public long doRemoteFunction(int value) {
+    return safeCall(value);
+  }
 
-        return safeCall(value);
+  private long checkLatency(int value) {
-    }
+    var startTime = System.currentTimeMillis();
+    var result = RemoteService.getRemoteService().doRemoteFunction(value);
+    var timeTaken = System.currentTimeMillis() - startTime;
 
-    private long checkLatency(int value) {
+    LOGGER.info("Time taken (ms): " + timeTaken);
-        RemoteService service = RemoteService.getRemoteService();
+    return result;
-        long startTime = System.currentTimeMillis();
+  }
-        long result = service.doRemoteFunction(value);
-        long timeTaken = System.currentTimeMillis() - startTime;
 
-        LOGGER.info("Time taken (ms): " + timeTaken);
+  private long safeCall(int value) {
-        return result;
+    var retries = 0;
-    }
+    var result = (long) FAILURE;
 
-    private long safeCall(int value) {
+    for (int i = 0; i < RETRIES; i++) {
+      if (retries >= RETRIES) {
+        return FAILURE;
+      }
 
-        int retries = 0;
+      if ((result = checkLatency(value)) == FAILURE) {
-        long result = -1;
+        LOGGER.info("Failed to reach remote: (" + (i + 1) + ")");
-
+        retries++;
-        for (int i = 0; i < RETRIES; i++) {
+        try {
-
+          sleep(DELAY_MS);
-            if (retries >= RETRIES) {
+        } catch (InterruptedException e) {
-                return -1;
+          LOGGER.error("Thread sleep state interrupted", e);
-            }
-
-            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;
+      } else {
+        break;
+      }
     }
+    return result;
+  }
 }
 ```
 
@@ -129,27 +126,28 @@ A client has a local service ambassador used to interact with the remote service
 ```java
 public class Client {
 
-    private ServiceAmbassador serviceAmbassador;
+  private static final Logger LOGGER = LoggerFactory.getLogger(Client.class);
+  private final ServiceAmbassador serviceAmbassador = new ServiceAmbassador();
 
-    Client() {
+  long useService(int value) {
-        serviceAmbassador = new ServiceAmbassador();
+    var result = serviceAmbassador.doRemoteFunction(value);
-    }
+    LOGGER.info("Service result: " + result);
-
+    return result;
-    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
-Client host1 = new Client();
+public class App {
-Client host2 = new Client();
+  public static void main(String[] args) {
-host1.useService(12);
+    var host1 = new Client();
-host2.useService(73);
+    var host2 = new Client();
+    host1.useService(12);
+    host2.useService(73);
+  }
+}
 ```
 
 ## Applicability

ambassador/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright (c) 2014-2016 Ilkka Seppälä
+    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
@@ -29,7 +29,7 @@
   <parent>
     <artifactId>java-design-patterns</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.21.0</version>
+    <version>1.22.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>ambassador</artifactId>

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -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.
  *
- * An ambassador service can be thought of as an out-of-process proxy that is co-located with
+ * <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
+ * the client. Similar to the proxy design pattern, the ambassador service provides an interface for
- * for another remote service. In addition to the interface, the ambassador provides extra
+ * another remote service. In addition to the interface, the ambassador provides extra functionality
- * functionality and features, specifically offloaded common connectivity tasks. This usually
+ * and features, specifically offloaded common connectivity tasks. This usually consists of
- * consists of monitoring, logging, routing, security etc. This is extremely useful in
+ * monitoring, logging, routing, security etc. This is extremely useful in legacy applications where
- * legacy applications where the codebase is difficult to modify and allows for improvements
+ * the codebase is difficult to modify and allows for improvements in the application's networking
- * in the application's networking capabilities.
+ * capabilities.
  *
- * In this example, we will the ({@link ServiceAmbassador}) class represents the ambassador while the
+ * <p>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) {
-    Client host1 = new Client();
+    var host1 = new Client();
-    Client host2 = new Client();
+    var 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -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) {
-    long result = serviceAmbassador.doRemoteFunction(value);
+    var 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 (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,19 +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 {
-  static final int THRESHOLD = 200;
+  private static final int THRESHOLD = 200;
   private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
   private static RemoteService service = null;
   private final RandomProvider randomProvider;
@@ -49,14 +50,16 @@ public class RemoteService implements RemoteServiceInterface {
   }
 
   /**
-   * This constuctor is used for testing purposes only.
+   * 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.
+   * Remote function takes a value and multiplies it by 10 taking a random amount of time. Will
-   * Will sometimes return -1. This imitates connectivity issues a client might have to account for.
+   * 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}.

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.ambassador;
 
 /**

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,19 +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 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 {
 
@@ -40,7 +39,8 @@ 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) {
@@ -48,21 +48,19 @@ public class ServiceAmbassador implements RemoteServiceInterface {
   }
 
   private long checkLatency(int value) {
-    long startTime = System.currentTimeMillis();
+    var startTime = System.currentTimeMillis();
-    long result = RemoteService.getRemoteService().doRemoteFunction(value);
+    var result = RemoteService.getRemoteService().doRemoteFunction(value);
-    long timeTaken = System.currentTimeMillis() - startTime;
+    var timeTaken = System.currentTimeMillis() - startTime;
 
     LOGGER.info("Time taken (ms): " + timeTaken);
     return result;
   }
 
   private long safeCall(int value) {
-
+    var retries = 0;
-    int retries = 0;
+    var result = (long) FAILURE;
-    long result = FAILURE;
 
     for (int i = 0; i < RETRIES; i++) {
-
       if (retries >= RETRIES) {
         return FAILURE;
       }

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+
 package com.iluwatar.ambassador.util;
 
 /**

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * 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;
@@ -27,10 +28,10 @@ import org.junit.jupiter.api.Test;
 /**
  * Application test
  */
-public class AppTest {
+class AppTest {
 
   @Test
-  public void test() {
+  void test() {
     App.main(new String[]{});
   }
 }

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * 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;
@@ -29,13 +30,12 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 /**
  * Test for {@link Client}
  */
-public class ClientTest {
+class ClientTest {
 
   @Test
-  public void test() {
+  void test() {
-
     Client client = new Client();
-    long result = client.useService(10);
+    var result = client.useService(10);
 
     assertTrue(result == 100 || result == RemoteService.FAILURE);
   }

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,36 +20,34 @@
  * 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;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 /**
  * Test for {@link RemoteService}
  */
-public class RemoteServiceTest {
+class RemoteServiceTest {
 
   @Test
-  public void testFailedCall() {
+  void testFailedCall() {
-    RemoteService remoteService = new RemoteService(
+    var remoteService = new RemoteService(new StaticRandomProvider(0.21));
-        new StaticRandomProvider(0.21));
+    var result = remoteService.doRemoteFunction(10);
-    long result = remoteService.doRemoteFunction(10);
     assertEquals(RemoteServiceInterface.FAILURE, result);
   }
 
   @Test
-  public void testSuccessfulCall() {
+  void testSuccessfulCall() {
-    RemoteService remoteService = new RemoteService(
+    var remoteService = new RemoteService(new StaticRandomProvider(0.2));
-        new StaticRandomProvider(0.2));
+    var result = remoteService.doRemoteFunction(10);
-    long result = remoteService.doRemoteFunction(10);
     assertEquals(100, result);
   }
 
-  private class StaticRandomProvider implements RandomProvider {
+  private static class StaticRandomProvider implements RandomProvider {
     private double value;
 
     StaticRandomProvider(double value) {

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

@@ -1,6 +1,6 @@
-/**
+/*
  * The MIT License
- * Copyright (c) 2014-2016 Ilkka Seppälä
+ * 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
@@ -20,6 +20,7 @@
  * 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;
@@ -29,10 +30,10 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 /**
  * Test for {@link ServiceAmbassador}
  */
-public class ServiceAmbassadorTest {
+class ServiceAmbassadorTest {
 
   @Test
-  public void test() {
+  void test() {
     long result = new ServiceAmbassador().doRemoteFunction(10);
     assertTrue(result == 100 || result == RemoteServiceInterface.FAILURE);
   }