test change

Page doesn't exist anymore, so changed to use web archive

LICENSE.md

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2014-2016 Ilkka Seppälä
+Copyright (c) 2014-2020 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

README.md

@@ -4,6 +4,7 @@
 
 # Design patterns implemented in Java
 
+
 [![Build status](https://travis-ci.org/iluwatar/java-design-patterns.svg?branch=master)](https://travis-ci.org/iluwatar/java-design-patterns)
 [![License MIT](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/iluwatar/java-design-patterns/master/LICENSE.md)
 [![Join the chat at https://gitter.im/iluwatar/java-design-patterns](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)

abstract-document/README.md

@@ -5,13 +5,13 @@ folder: abstract-document
 permalink: /patterns/abstract-document/
 categories: Structural
 tags: 
- - Java
- - Difficulty-Intermediate
+ - Extensibility
 ---
 
 ## Intent
 Achieve flexibility of untyped languages and keep the type-safety 
 
+## Class diagram
 ![alt text](./etc/abstract-document.png "Abstract Document Traits and Domain")
 
 
@@ -26,4 +26,4 @@ Use the Abstract Document Pattern when
 ## Credits
 
 * [Wikipedia: Abstract Document Pattern](https://en.wikipedia.org/wiki/Abstract_Document_Pattern)
-* [Martin Fowler: Dealing with properties](http://martinfowler.com/apsupp/properties.pdf)
+* [Martin Fowler: Dealing with properties](http://martinfowler.com/apsupp/properties.pdf)

abstract-document/etc/abstract-document.urm.puml

@@ -0,0 +1,65 @@
+@startuml
+package com.iluwatar.abstractdocument.domain.enums {
+  enum Property {
+    + MODEL {static}
+    + PARTS {static}
+    + PRICE {static}
+    + TYPE {static}
+    + valueOf(name : String) : Property {static}
+    + values() : Property[] {static}
+  }
+}
+package com.iluwatar.abstractdocument.domain {
+  class Car {
+    + Car(properties : Map<String, Object>)
+  }
+  interface HasModel {
+    + getModel() : Optional<String>
+  }
+  interface HasParts {
+    + getParts() : Stream<Part>
+  }
+  interface HasPrice {
+    + getPrice() : Optional<Number>
+  }
+  interface HasType {
+    + getType() : Optional<String>
+  }
+  class Part {
+    + Part(properties : Map<String, Object>)
+  }
+}
+package com.iluwatar.abstractdocument {
+  abstract class AbstractDocument {
+    - properties : Map<String, Object>
+    # AbstractDocument(properties : Map<String, Object>)
+    + children(key : String, constructor : Function<Map<String, Object>, T>) : Stream<T>
+    + get(key : String) : Object
+    + put(key : String, value : Object)
+    + toString() : String
+  }
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+  }
+  interface Document {
+    + children(String, Function<Map<String, Object>, T>) : Stream<T> {abstract}
+    + get(String) : Object {abstract}
+    + put(String, Object) {abstract}
+  }
+}
+AbstractDocument ..|> Document 
+Car ..|> HasModel 
+Car ..|> HasPrice 
+Car ..|> HasParts 
+Car --|> AbstractDocument 
+HasModel --|> Document 
+HasParts --|> Document 
+HasPrice --|> Document 
+HasType --|> Document 
+Part ..|> HasType 
+Part ..|> HasModel 
+Part ..|> HasPrice 
+Part --|> AbstractDocument 
+@enduml

abstract-document/pom.xml

@@ -1,42 +1,55 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    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.
-
--->
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <parent>
-        <artifactId>java-design-patterns</artifactId>
-        <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
-    </parent>
-    <artifactId>abstract-document</artifactId>
-    <dependencies>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+<!-- 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. -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<artifactId>java-design-patterns</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>abstract-document</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<!-- Maven assembly plugin is invoked with default setting which we have 
+				in parent pom and specifying the class having main method -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.abstractdocument.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

abstract-document/src/main/java/com/iluwatar/abstractdocument/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+module com.iluwatar.abstractdocument {
+	requires org.slf4j;
+}

abstract-factory/README.md

@@ -5,9 +5,7 @@ folder: abstract-factory
 permalink: /patterns/abstract-factory/
 categories: Creational
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Also known as
@@ -157,6 +155,9 @@ public static void main(String[] args) {
 }
 ```
 
+## Class diagram
+![alt text](./etc/abstract-factory.urm.png "Abstract Factory class diagram")
+
 
 ## Applicability
 Use the Abstract Factory pattern when

abstract-factory/etc/abstract-factory.urm.puml

@@ -0,0 +1,101 @@
+@startuml
+package com.iluwatar.abstractfactory {
+  class App {
+    - LOGGER : Logger {static}
+    - army : Army
+    - castle : Castle
+    - king : King
+    + App()
+    + createKingdom(factory : KingdomFactory)
+    + getArmy() : Army
+    ~ getArmy(factory : KingdomFactory) : Army
+    + getCastle() : Castle
+    ~ getCastle(factory : KingdomFactory) : Castle
+    + getKing() : King
+    ~ getKing(factory : KingdomFactory) : King
+    + main(args : String[]) {static}
+    - setArmy(army : Army)
+    - setCastle(castle : Castle)
+    - setKing(king : King)
+  }
+  class FactoryMaker {
+    + FactoryMaker()
+    + makeFactory(type : KingdomType) : KingdomFactory {static}
+  }
+  enum KingdomType {
+    + ELF {static}
+    + ORC {static}
+    + valueOf(name : String) : KingdomType {static}
+    + values() : KingdomType[] {static}
+  }
+  interface Army {
+    + getDescription() : String {abstract}
+  }
+  interface Castle {
+    + getDescription() : String {abstract}
+  }
+  class ElfArmy {
+    ~ DESCRIPTION : String {static}
+    + ElfArmy()
+    + getDescription() : String
+  }
+  class ElfCastle {
+    ~ DESCRIPTION : String {static}
+    + ElfCastle()
+    + getDescription() : String
+  }
+  class ElfKing {
+    ~ DESCRIPTION : String {static}
+    + ElfKing()
+    + getDescription() : String
+  }
+  class ElfKingdomFactory {
+    + ElfKingdomFactory()
+    + createArmy() : Army
+    + createCastle() : Castle
+    + createKing() : King
+  }
+  interface King {
+    + getDescription() : String {abstract}
+  }
+  interface KingdomFactory {
+    + createArmy() : Army {abstract}
+    + createCastle() : Castle {abstract}
+    + createKing() : King {abstract}
+  }
+  class OrcArmy {
+    ~ DESCRIPTION : String {static}
+    + OrcArmy()
+    + getDescription() : String
+  }
+  class OrcCastle {
+    ~ DESCRIPTION : String {static}
+    + OrcCastle()
+    + getDescription() : String
+  }
+  class OrcKing {
+    ~ DESCRIPTION : String {static}
+    + OrcKing()
+    + getDescription() : String
+  }
+  class OrcKingdomFactory {
+    + OrcKingdomFactory()
+    + createArmy() : Army
+    + createCastle() : Castle
+    + createKing() : King
+  }
+}
+KingdomType ..+ FactoryMaker
+App -->  "-castle" Castle
+FactoryMaker ..+ App
+App -->  "-king" King
+App -->  "-army" Army
+ElfArmy ..|> Army 
+ElfCastle ..|> Castle 
+ElfKing ..|> King 
+ElfKingdomFactory ..|> KingdomFactory 
+OrcArmy ..|> Army 
+OrcCastle ..|> Castle 
+OrcKing ..|> King 
+OrcKingdomFactory ..|> KingdomFactory 
+@enduml

abstract-factory/pom.xml

@@ -1,42 +1,56 @@
 <?xml version="1.0"?>
-<!--
-
-    The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
--->
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
-  </parent>
-  <artifactId>abstract-factory</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+<!-- 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. -->
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>abstract-factory</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<!-- Maven assembly plugin is invoked with default setting which we have 
+				in parent pom and specifying the class having main method -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.abstractfactory.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

abstract-factory/src/main/java/com/iluwatar/abstractfactory/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+module com.iluwatar.abstractfactory {
+	requires org.slf4j;
+}

acyclic-visitor/README.md

@@ -5,17 +5,18 @@ folder: acyclic-visitor
 permalink: /patterns/acyclic-visitor/
 categories: Behavioral
 tags:
- - Java
- - Difficulty-Intermediate
+ - Extensibility
 ---
 
-![alt text](./etc/acyclic-visitor.png "Acyclic Visitor")
-
 ## Intent
 Allow new functions to be added to existing class hierarchies without affecting those hierarchies, and without creating the troublesome dependency cycles that are inherent to the GOF VISITOR Pattern.
 
+## Class diagram
+![alt text](./etc/acyclic-visitor.png "Acyclic Visitor")
+
 ## Applicability
 This pattern can be used:
+
 * When you need to add a new function to an existing hierarchy without the need to alter or affect that hierarchy.
 * When there are functions that operate upon a hierarchy, but which do not belong in the hierarchy itself. e.g. the ConfigureForDOS / ConfigureForUnix / ConfigureForX issue.
 * When you need to perform very different operations on an object depending upon its type.
@@ -24,11 +25,13 @@ This pattern can be used:
 
 ## Consequences
 The good:
+
 * No dependency cycles between class hierarchies.
 * No need to recompile all the visitors if a new one is added.
 * Does not cause compilation failure in existing visitors if class hierarchy has a new member.
 
 The bad:
+
 * Violates the principle of least surprise or Liskov's Substitution principle by showing that it can accept all visitors but actually only being interested in particular visitors.
 * Parallel hierarchy of visitors has to be created for all members in visitable class hierarchy.
 

acyclic-visitor/etc/acyclic-visitor.urm.puml

@@ -0,0 +1,53 @@
+@startuml
+package com.iluwatar.acyclicvisitor {
+  interface AllModemVisitor {
+  }
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class ConfigureForDosVisitor {
+    - LOGGER : Logger {static}
+    + ConfigureForDosVisitor()
+    + visit(hayes : Hayes)
+    + visit(zoom : Zoom)
+  }
+  class ConfigureForUnixVisitor {
+    - LOGGER : Logger {static}
+    + ConfigureForUnixVisitor()
+    + visit(zoom : Zoom)
+  }
+  class Hayes {
+    - LOGGER : Logger {static}
+    + Hayes()
+    + accept(modemVisitor : ModemVisitor)
+    + toString() : String
+  }
+  interface HayesVisitor {
+    + visit(Hayes) {abstract}
+  }
+  abstract class Modem {
+    + Modem()
+    + accept(ModemVisitor) {abstract}
+  }
+  interface ModemVisitor {
+  }
+  class Zoom {
+    - LOGGER : Logger {static}
+    + Zoom()
+    + accept(modemVisitor : ModemVisitor)
+    + toString() : String
+  }
+  interface ZoomVisitor {
+    + visit(Zoom) {abstract}
+  }
+}
+AllModemVisitor --|> ZoomVisitor 
+AllModemVisitor --|> HayesVisitor 
+ConfigureForDosVisitor ..|> AllModemVisitor 
+ConfigureForUnixVisitor ..|> ZoomVisitor 
+Hayes --|> Modem 
+HayesVisitor --|> ModemVisitor 
+Zoom --|> Modem 
+ZoomVisitor --|> ModemVisitor 
+@enduml

acyclic-visitor/pom.xml

@@ -1,38 +1,29 @@
-<!--
-
-    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.
-
--->
+<!-- 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. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
-	
+
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.22.0-SNAPSHOT</version>
+		<version>1.23.0-SNAPSHOT</version>
 	</parent>
-	
+
 	<artifactId>acyclic-visitor</artifactId>
 
 	<properties>
@@ -53,19 +44,40 @@
 		<dependency>
 			<groupId>uk.org.lidalia</groupId>
 			<artifactId>slf4j-test</artifactId>
-			<version>1.0.0</version>
+			<version>1.2.0</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
 			<scope>test</scope>
 		</dependency>
-    	<dependency>
-      		<groupId>org.junit.jupiter</groupId>
-      		<artifactId>junit-jupiter-engine</artifactId>
-      		<scope>test</scope>
-    	</dependency>
 		<dependency>
 			<groupId>org.mockito</groupId>
 			<artifactId>mockito-all</artifactId>
-			<version>1.9.5</version>
+			<version>1.10.19</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
+	<build>
+    <plugins>
+      <!-- Maven assembly plugin is invoked with default setting which we have 
+        in parent pom and specifying the class having main method -->
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.acyclicvisitor.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
 </project>

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+module com.iluwatar.acyclicvisitor {
+	requires org.slf4j;
+}

adapter/README.md

@@ -5,9 +5,7 @@ folder: adapter
 permalink: /patterns/adapter/
 categories: Structural
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Beginner
+ - Gang of Four
 ---
 
 ## Also known as
@@ -97,6 +95,9 @@ var captain = new Captain(new FishingBoatAdapter());
 captain.row();
 ```
 
+## Class diagram
+![alt text](./etc/adapter.urm.png "Adapter class diagram")
+
 ## Applicability
 Use the Adapter pattern when
 

adapter/etc/adapter.urm.puml

@@ -0,0 +1,31 @@
+@startuml
+package com.iluwatar.adapter {
+  class App {
+    - App()
+    + main(args : String[]) {static}
+  }
+  class Captain {
+    - rowingBoat : RowingBoat
+    + Captain()
+    + Captain(boat : RowingBoat)
+    ~ row()
+    ~ setRowingBoat(boat : RowingBoat)
+  }
+  ~class FishingBoat {
+    - LOGGER : Logger {static}
+    ~ FishingBoat()
+    ~ sail()
+  }
+  class FishingBoatAdapter {
+    - boat : FishingBoat
+    + FishingBoatAdapter()
+    + row()
+  }
+  interface RowingBoat {
+    + row() {abstract}
+  }
+}
+FishingBoatAdapter -->  "-boat" FishingBoat
+Captain -->  "-rowingBoat" RowingBoat
+FishingBoatAdapter ..|> RowingBoat 
+@enduml

adapter/pom.xml

@@ -1,47 +1,61 @@
 <?xml version="1.0"?>
-<!--
-
-    The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
--->
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
-  </parent>
-  <artifactId>adapter</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+<!-- 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. -->
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>adapter</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<!-- Maven assembly plugin is invoked with default setting which we have 
+				in parent pom and specifying the class having main method -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.adapter.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

aggregator-microservices/README.md

@@ -5,8 +5,7 @@ folder: aggregator-microservices
 permalink: /patterns/aggregator-microservices/
 categories: Architectural
 tags:
-- Java
-- Spring
+- Cloud distributed
 ---
 
 ## Intent
@@ -18,6 +17,8 @@ More variations of the aggregator are:
 - Chained Microservice Design Pattern: In this case each microservice is dependent/ chained to a series 
 of other microservices.
 
+## Class diagram
+
 ![alt text](./etc/aggregator-microservice.png "Aggregator Microservice")
 
 ## Applicability
@@ -26,4 +27,4 @@ Use the Aggregator Microservices pattern when you need a unified API for various
 
 ## Credits
 
-* [Microservice Design Patterns](http://blog.arungupta.me/microservice-design-patterns/)
+* [Microservice Design Patterns](http://web.archive.org/web/20190705163602/http://blog.arungupta.me/microservice-design-patterns/)

aggregator-microservices/aggregator-service/etc/aggregator-service.urm.puml

@@ -0,0 +1,43 @@
+@startuml
+package com.iluwatar.aggregator.microservices {
+  class Aggregator {
+    - informationClient : ProductInformationClient
+    - inventoryClient : ProductInventoryClient
+    + Aggregator()
+    + getProduct() : Product
+  }
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class Product {
+    - productInventories : int
+    - title : String
+    + Product()
+    + getProductInventories() : int
+    + getTitle() : String
+    + setProductInventories(productInventories : int)
+    + setTitle(title : String)
+  }
+  interface ProductInformationClient {
+    + getProductTitle() : String {abstract}
+  }
+  class ProductInformationClientImpl {
+    - LOGGER : Logger {static}
+    + ProductInformationClientImpl()
+    + getProductTitle() : String
+  }
+  interface ProductInventoryClient {
+    + getProductInventories() : Integer {abstract}
+  }
+  class ProductInventoryClientImpl {
+    - LOGGER : Logger {static}
+    + ProductInventoryClientImpl()
+    + getProductInventories() : Integer
+  }
+}
+Aggregator -->  "-informationClient" ProductInformationClient
+Aggregator -->  "-inventoryClient" ProductInventoryClient
+ProductInformationClientImpl ..|> ProductInformationClient 
+ProductInventoryClientImpl ..|> ProductInventoryClient 
+@enduml

aggregator-microservices/aggregator-service/pom.xml

@@ -1,73 +1,81 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    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.
-
--->
+<!-- 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. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <parent>
-        <artifactId>aggregator-microservices</artifactId>
-        <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
-    </parent>
-    <modelVersion>4.0.0</modelVersion>
-    <artifactId>aggregator-service</artifactId>
-    <packaging>jar</packaging>
-    <dependencies>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-webmvc</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-web</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.mockito</groupId>
-            <artifactId>mockito-core</artifactId>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>aggregator-microservices</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
+	<artifactId>aggregator-service</artifactId>
+	<packaging>jar</packaging>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-webmvc</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-maven-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>repackage</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-    </build>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<!-- Maven assembly plugin is invoked with default setting which we have 
+				in parent pom and specifying the class having main method -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.aggregator.microservices.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

aggregator-microservices/etc/aggregator-microservices.urm.puml

@@ -0,0 +1,2 @@
+@startuml
+@enduml

aggregator-microservices/information-microservice/etc/information-microservice.urm.puml

@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.information.microservice {
+  class InformationApplication {
+    + InformationApplication()
+    + main(args : String[]) {static}
+  }
+  class InformationController {
+    + InformationController()
+    + getProductTitle() : String
+  }
+}
+@enduml

aggregator-microservices/information-microservice/pom.xml

@@ -1,70 +1,76 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    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.
-
--->
+<!-- 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. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <parent>
-        <artifactId>aggregator-microservices</artifactId>
-        <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
-    </parent>
-    <modelVersion>4.0.0</modelVersion>
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>aggregator-microservices</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
 
-    <artifactId>information-microservice</artifactId>
-    <packaging>jar</packaging>
+	<artifactId>information-microservice</artifactId>
+	<packaging>jar</packaging>
 
-    <dependencies>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-webmvc</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-web</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-webmvc</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-maven-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>repackage</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-    </build>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.information.microservices.InformationApplication</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

aggregator-microservices/inventory-microservice/etc/inventory-microservice.urm.puml

@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.inventory.microservice {
+  class InventoryApplication {
+    + InventoryApplication()
+    + main(args : String[]) {static}
+  }
+  class InventoryController {
+    + InventoryController()
+    + getProductInventories() : int
+  }
+}
+@enduml

aggregator-microservices/inventory-microservice/pom.xml

@@ -1,69 +1,75 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    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.
-
--->
+<!-- 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. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <parent>
-        <artifactId>aggregator-microservices</artifactId>
-        <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
-    </parent>
-    <modelVersion>4.0.0</modelVersion>
-    <artifactId>inventory-microservice</artifactId>
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>aggregator-microservices</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
+	<artifactId>inventory-microservice</artifactId>
 
-    <packaging>jar</packaging>
-    <dependencies>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-webmvc</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-web</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+	<packaging>jar</packaging>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-webmvc</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-maven-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>repackage</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-    </build>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.inventory.microservices.InventoryApplication</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

aggregator-microservices/pom.xml

@@ -29,7 +29,7 @@
     <parent>
         <artifactId>java-design-patterns</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
+        <version>1.23.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
     <artifactId>aggregator-microservices</artifactId>

ambassador/README.md

@@ -5,8 +5,7 @@ folder: ambassador
 permalink: /patterns/ambassador/
 categories: Structural
 tags:
- - Java
- - Difficulty-Intermediate
+ - Decoupling
 ---
 
 ## Intent
@@ -150,6 +149,9 @@ public class App {
 }
 ```
 
+## Class diagram
+![alt text](./etc/ambassador.urm.png "Ambassador class diagram")
+
 ## Applicability
 Ambassador is applicable when working with a legacy remote service that cannot
 be modified or would be extremely difficult to modify. Connectivity features can

ambassador/etc/ambassador.urm.puml

@@ -0,0 +1,47 @@
+@startuml
+package com.iluwatar.ambassador.util {
+  interface RandomProvider {
+    + random() : double {abstract}
+  }
+}
+package com.iluwatar.ambassador {
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class Client {
+    - LOGGER : Logger {static}
+    - serviceAmbassador : ServiceAmbassador
+    + Client()
+    ~ useService(value : int) : long
+  }
+  class RemoteService {
+    - LOGGER : Logger {static}
+    - THRESHOLD : int {static}
+    - randomProvider : RandomProvider
+    - service : RemoteService {static}
+    - RemoteService()
+    ~ RemoteService(randomProvider : RandomProvider)
+    + doRemoteFunction(value : int) : long
+    ~ getRemoteService() : RemoteService {static}
+  }
+  ~interface RemoteServiceInterface {
+    + FAILURE : int {static}
+    + doRemoteFunction(int) : long {abstract}
+  }
+  class ServiceAmbassador {
+    - DELAY_MS : int {static}
+    - LOGGER : Logger {static}
+    - RETRIES : int {static}
+    ~ ServiceAmbassador()
+    - checkLatency(value : int) : long
+    + doRemoteFunction(value : int) : long
+    - safeCall(value : int) : long
+  }
+}
+RemoteService -->  "-service" RemoteService
+Client -->  "-serviceAmbassador" ServiceAmbassador
+RemoteService -->  "-randomProvider" RandomProvider
+RemoteService ..|> RemoteServiceInterface 
+ServiceAmbassador ..|> RemoteServiceInterface 
+@enduml

ambassador/pom.xml

@@ -1,43 +1,53 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    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.
-
--->
+<!-- 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. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <parent>
-    <artifactId>java-design-patterns</artifactId>
-    <groupId>com.iluwatar</groupId>
-    <version>1.22.0-SNAPSHOT</version>
-  </parent>
-  <modelVersion>4.0.0</modelVersion>
-  <artifactId>ambassador</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>java-design-patterns</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
+	<artifactId>ambassador</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.ambassador.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

api-gateway/README.md

@@ -5,9 +5,8 @@ folder: api-gateway
 permalink: /patterns/api-gateway/
 categories: Architectural
 tags:
-- Java
-- Difficulty-Intermediate
-- Spring
+- Cloud distributed
+- Decoupling
 ---
 
 ## Intent
@@ -15,6 +14,7 @@ tags:
 Aggregate calls to microservices in a single location: the API Gateway. The user makes a single
 call to the API Gateway, and the API Gateway then calls each relevant microservice.
 
+## Class diagram
 ![alt text](./etc/api-gateway.png "API Gateway")
 
 ## Applicability

api-gateway/api-gateway-service/etc/api-gateway-service.urm.puml

@@ -0,0 +1,48 @@
+@startuml
+package com.iluwatar.api.gateway {
+  class ApiGateway {
+    - imageClient : ImageClient
+    - priceClient : PriceClient
+    + ApiGateway()
+    + getProductDesktop() : DesktopProduct
+    + getProductMobile() : MobileProduct
+  }
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class DesktopProduct {
+    - imagePath : String
+    - price : String
+    + DesktopProduct()
+    + getImagePath() : String
+    + getPrice() : String
+    + setImagePath(imagePath : String)
+    + setPrice(price : String)
+  }
+  interface ImageClient {
+    + getImagePath() : String {abstract}
+  }
+  class ImageClientImpl {
+    + ImageClientImpl()
+    + getImagePath() : String
+  }
+  class MobileProduct {
+    - price : String
+    + MobileProduct()
+    + getPrice() : String
+    + setPrice(price : String)
+  }
+  interface PriceClient {
+    + getPrice() : String {abstract}
+  }
+  class PriceClientImpl {
+    + PriceClientImpl()
+    + getPrice() : String
+  }
+}
+ApiGateway -->  "-imageClient" ImageClient
+ApiGateway -->  "-priceClient" PriceClient
+ImageClientImpl ..|> ImageClient 
+PriceClientImpl ..|> PriceClient 
+@enduml

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

@@ -29,7 +29,7 @@
   <parent>
     <artifactId>api-gateway</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>api-gateway-service</artifactId>
@@ -68,6 +68,21 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.api.gateway.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
     </plugins>
   </build>
 </project>

api-gateway/etc/api-gateway.urm.puml

@@ -0,0 +1,2 @@
+@startuml
+@enduml

api-gateway/image-microservice/etc/image-microservice.urm.puml

@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.image.microservice {
+  class ImageApplication {
+    + ImageApplication()
+    + main(args : String[]) {static}
+  }
+  class ImageController {
+    + ImageController()
+    + getImagePath() : String
+  }
+}
+@enduml

api-gateway/image-microservice/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <artifactId>api-gateway</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>image-microservice</artifactId>
@@ -63,6 +63,21 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.image.microservice.ImageApplication</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
     </plugins>
   </build>
 </project>

api-gateway/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <artifactId>java-design-patterns</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>api-gateway</artifactId>

api-gateway/price-microservice/etc/price-microservice.urm.puml

@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.price.microservice {
+  class PriceApplication {
+    + PriceApplication()
+    + main(args : String[]) {static}
+  }
+  class PriceController {
+    + PriceController()
+    + getPrice() : String
+  }
+}
+@enduml

api-gateway/price-microservice/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <artifactId>api-gateway</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
 
   <modelVersion>4.0.0</modelVersion>
@@ -65,6 +65,21 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.price.microservices.PriceApplication</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
     </plugins>
   </build>
 </project>

async-method-invocation/README.md

@@ -5,9 +5,6 @@ folder: async-method-invocation
 permalink: /patterns/async-method-invocation/
 categories: Concurrency
 tags:
- - Java
- - Difficulty-Intermediate
- - Functional
  - Reactive
 ---
 
@@ -17,6 +14,7 @@ is not blocked while waiting results of tasks. The pattern provides parallel
 processing of multiple independent tasks and retrieving the results via
 callbacks or waiting until everything is done. 
 
+# Class diagram
 ![alt text](./etc/async-method-invocation.png "Async Method Invocation")
 
 ## Applicability

async-method-invocation/etc/async-method-invocation.urm.puml

@@ -0,0 +1,51 @@
+@startuml
+package com.iluwatar.async.method.invocation {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    - callback(name : String) : AsyncCallback<T> {static}
+    - lazyval(value : T, delayMillis : long) : Callable<T> {static}
+    - log(msg : String) {static}
+    + main(args : String[]) {static}
+  }
+  interface AsyncCallback<T> {
+    + onComplete(T, Optional<Exception>) {abstract}
+  }
+  interface AsyncExecutor {
+    + endProcess(AsyncResult<T>) : T {abstract}
+    + startProcess(Callable<T>) : AsyncResult<T> {abstract}
+    + startProcess(Callable<T>, AsyncCallback<T>) : AsyncResult<T> {abstract}
+  }
+  interface AsyncResult<T> {
+    + await() {abstract}
+    + getValue() : T {abstract}
+    + isCompleted() : boolean {abstract}
+  }
+  class ThreadAsyncExecutor {
+    - idx : AtomicInteger
+    + ThreadAsyncExecutor()
+    + endProcess(asyncResult : AsyncResult<T>) : T
+    + startProcess(task : Callable<T>) : AsyncResult<T>
+    + startProcess(task : Callable<T>, callback : AsyncCallback<T>) : AsyncResult<T>
+  }
+  -class CompletableResult<T> {
+    ~ COMPLETED : int {static}
+    ~ FAILED : int {static}
+    ~ RUNNING : int {static}
+    ~ callback : Optional<AsyncCallback<T>>
+    ~ exception : Exception
+    ~ lock : Object
+    ~ state : int
+    ~ value : T
+    ~ CompletableResult<T>(callback : AsyncCallback<T>)
+    + await()
+    + getValue() : T
+    + isCompleted() : boolean
+    ~ setException(exception : Exception)
+    ~ setValue(value : T)
+  }
+}
+CompletableResult ..+ ThreadAsyncExecutor
+ThreadAsyncExecutor ..|> AsyncExecutor 
+CompletableResult ..|> AsyncResult 
+@enduml

async-method-invocation/pom.xml

@@ -1,52 +1,64 @@
 <?xml version="1.0"?>
-<!--
-
-    The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
--->
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
-  </parent>
-  <artifactId>async-method-invocation</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+<!-- 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. -->
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>async-method-invocation</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.async.method.invocation.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

balking/README.md

@@ -5,14 +5,14 @@ folder: balking
 permalink: /patterns/balking/
 categories: Concurrency
 tags:
- - Java
- - Difficulty-Beginner
+ - Decoupling
 ---
 
 ## Intent
 Balking Pattern is used to prevent an object from executing certain code if it is an
 incomplete or inappropriate state
 
+## Class diagram
 ![alt text](./etc/balking.png "Balking")
 
 ## Applicability

balking/etc/balking.urm.puml

@@ -0,0 +1,30 @@
+@startuml
+package com.iluwatar.balking {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+  }
+  interface DelayProvider {
+    + executeAfterDelay(long, TimeUnit, Runnable) {abstract}
+  }
+  class WashingMachine {
+    - LOGGER : Logger {static}
+    - delayProvider : DelayProvider
+    - washingMachineState : WashingMachineState
+    + WashingMachine()
+    + WashingMachine(delayProvider : DelayProvider)
+    + endOfWashing()
+    + getWashingMachineState() : WashingMachineState
+    + wash()
+  }
+  enum WashingMachineState {
+    + ENABLED {static}
+    + WASHING {static}
+    + valueOf(name : String) : WashingMachineState {static}
+    + values() : WashingMachineState[] {static}
+  }
+}
+WashingMachine -->  "-washingMachineState" WashingMachineState
+WashingMachine -->  "-delayProvider" DelayProvider
+@enduml

balking/pom.xml

@@ -1,46 +1,54 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    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.
-
--->
+<!-- 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. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <parent>
-    <artifactId>java-design-patterns</artifactId>
-    <groupId>com.iluwatar</groupId>
-    <version>1.22.0-SNAPSHOT</version>
-  </parent>
-  <modelVersion>4.0.0</modelVersion>
-
-  <artifactId>balking</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
-
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>java-design-patterns</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
 
+	<artifactId>balking</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.balking.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

bridge/README.md

@@ -5,9 +5,7 @@ folder: bridge
 permalink: /patterns/bridge/
 categories: Structural
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Also known as
@@ -179,6 +177,9 @@ hammer.unwield();
 // The item's glow fades.
 ```
 
+## Class diagram
+![alt text](./etc/bridge.urm.png "Bridge class diagram")
+
 ## Applicability
 Use the Bridge pattern when
 

bridge/etc/bridge.urm.puml

@@ -0,0 +1,58 @@
+@startuml
+package com.iluwatar.bridge {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+  }
+  interface Enchantment {
+    + apply() {abstract}
+    + onActivate() {abstract}
+    + onDeactivate() {abstract}
+  }
+  class FlyingEnchantment {
+    - LOGGER : Logger {static}
+    + FlyingEnchantment()
+    + apply()
+    + onActivate()
+    + onDeactivate()
+  }
+  class Hammer {
+    - LOGGER : Logger {static}
+    - enchantment : Enchantment
+    + Hammer(enchantment : Enchantment)
+    + getEnchantment() : Enchantment
+    + swing()
+    + unwield()
+    + wield()
+  }
+  class SoulEatingEnchantment {
+    - LOGGER : Logger {static}
+    + SoulEatingEnchantment()
+    + apply()
+    + onActivate()
+    + onDeactivate()
+  }
+  class Sword {
+    - LOGGER : Logger {static}
+    - enchantment : Enchantment
+    + Sword(enchantment : Enchantment)
+    + getEnchantment() : Enchantment
+    + swing()
+    + unwield()
+    + wield()
+  }
+  interface Weapon {
+    + getEnchantment() : Enchantment {abstract}
+    + swing() {abstract}
+    + unwield() {abstract}
+    + wield() {abstract}
+  }
+}
+Sword -->  "-enchantment" Enchantment
+Hammer -->  "-enchantment" Enchantment
+FlyingEnchantment ..|> Enchantment 
+Hammer ..|> Weapon 
+SoulEatingEnchantment ..|> Enchantment 
+Sword ..|> Weapon 
+@enduml

bridge/pom.xml

@@ -1,47 +1,59 @@
 <?xml version="1.0"?>
-<!--
-
-    The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
--->
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
-  </parent>
-  <artifactId>bridge</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+<!-- 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. -->
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>bridge</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.bridge.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
 </project>

builder/README.md

@@ -5,9 +5,7 @@ folder: builder
 permalink: /patterns/builder/
 categories: Creational
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Intent
@@ -113,6 +111,9 @@ And then it can be used as:
 var mage = new Hero.Builder(Profession.MAGE, "Riobard").withHairColor(HairColor.BLACK).withWeapon(Weapon.DAGGER).build();
 ```
 
+## Class diagram
+![alt text](./etc/builder.urm.png "Builder class diagram")
+
 ## Applicability
 Use the Builder pattern when
 

builder/etc/builder.urm.puml

@@ -0,0 +1,100 @@
+@startuml
+package com.iluwatar.builder {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+  }
+  enum Armor {
+    + CHAIN_MAIL {static}
+    + CLOTHES {static}
+    + LEATHER {static}
+    + PLATE_MAIL {static}
+    - title : String
+    + toString() : String
+    + valueOf(name : String) : Armor {static}
+    + values() : Armor[] {static}
+  }
+  enum HairColor {
+    + BLACK {static}
+    + BLOND {static}
+    + BROWN {static}
+    + RED {static}
+    + WHITE {static}
+    + toString() : String
+    + valueOf(name : String) : HairColor {static}
+    + values() : HairColor[] {static}
+  }
+  enum HairType {
+    + BALD {static}
+    + CURLY {static}
+    + LONG_CURLY {static}
+    + LONG_STRAIGHT {static}
+    + SHORT {static}
+    - title : String
+    + toString() : String
+    + valueOf(name : String) : HairType {static}
+    + values() : HairType[] {static}
+  }
+  class Hero {
+    - armor : Armor
+    - hairColor : HairColor
+    - hairType : HairType
+    - name : String
+    - profession : Profession
+    - weapon : Weapon
+    - Hero(builder : Builder)
+    + getArmor() : Armor
+    + getHairColor() : HairColor
+    + getHairType() : HairType
+    + getName() : String
+    + getProfession() : Profession
+    + getWeapon() : Weapon
+    + toString() : String
+  }
+  class Builder {
+    - armor : Armor
+    - hairColor : HairColor
+    - hairType : HairType
+    - name : String
+    - profession : Profession
+    - weapon : Weapon
+    + Builder(profession : Profession, name : String)
+    + build() : Hero
+    + withArmor(armor : Armor) : Builder
+    + withHairColor(hairColor : HairColor) : Builder
+    + withHairType(hairType : HairType) : Builder
+    + withWeapon(weapon : Weapon) : Builder
+  }
+  enum Profession {
+    + MAGE {static}
+    + PRIEST {static}
+    + THIEF {static}
+    + WARRIOR {static}
+    + toString() : String
+    + valueOf(name : String) : Profession {static}
+    + values() : Profession[] {static}
+  }
+  enum Weapon {
+    + AXE {static}
+    + BOW {static}
+    + DAGGER {static}
+    + SWORD {static}
+    + WARHAMMER {static}
+    + toString() : String
+    + valueOf(name : String) : Weapon {static}
+    + values() : Weapon[] {static}
+  }
+}
+Hero -->  "-profession" Profession
+Builder ..+ Hero
+Hero -->  "-armor" Armor
+Builder -->  "-hairColor" HairColor
+Builder -->  "-weapon" Weapon
+Builder -->  "-hairType" HairType
+Hero -->  "-hairColor" HairColor
+Builder -->  "-profession" Profession
+Hero -->  "-weapon" Weapon
+Hero -->  "-hairType" HairType
+Builder -->  "-armor" Armor
+@enduml

builder/pom.xml

@@ -1,42 +1,54 @@
 <?xml version="1.0"?>
-<!--
-
-    The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
--->
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
-  </parent>
-  <artifactId>builder</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+<!-- 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. -->
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>builder</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.builder.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
 </project>

business-delegate/README.md

@@ -3,10 +3,9 @@ layout: pattern
 title: Business Delegate
 folder: business-delegate
 permalink: /patterns/business-delegate/
-categories: Business Tier
+categories: Structural
 tags:
- - Java
- - Difficulty-Intermediate
+ - Decoupling
 ---
 
 ## Intent
@@ -15,6 +14,7 @@ presentation and business tiers. By using the pattern we gain loose coupling
 between the tiers and encapsulate knowledge about how to locate, connect to,
 and interact with the business objects that make up the application.
 
+## Class diagram
 ![alt text](./etc/business-delegate.png "Business Delegate")
 
 ## Applicability

business-delegate/etc/business-delegate.urm.puml

@@ -0,0 +1,57 @@
+@startuml
+package com.iluwatar.business.delegate {
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class BusinessDelegate {
+    - businessService : BusinessService
+    - lookupService : BusinessLookup
+    - serviceType : ServiceType
+    + BusinessDelegate()
+    + doTask()
+    + setLookupService(businessLookup : BusinessLookup)
+    + setServiceType(serviceType : ServiceType)
+  }
+  class BusinessLookup {
+    - ejbService : EjbService
+    - jmsService : JmsService
+    + BusinessLookup()
+    + getBusinessService(serviceType : ServiceType) : BusinessService
+    + setEjbService(ejbService : EjbService)
+    + setJmsService(jmsService : JmsService)
+  }
+  interface BusinessService {
+    + doProcessing() {abstract}
+  }
+  class Client {
+    - businessDelegate : BusinessDelegate
+    + Client(businessDelegate : BusinessDelegate)
+    + doTask()
+  }
+  class EjbService {
+    - LOGGER : Logger {static}
+    + EjbService()
+    + doProcessing()
+  }
+  class JmsService {
+    - LOGGER : Logger {static}
+    + JmsService()
+    + doProcessing()
+  }
+  enum ServiceType {
+    + EJB {static}
+    + JMS {static}
+    + valueOf(name : String) : ServiceType {static}
+    + values() : ServiceType[] {static}
+  }
+}
+BusinessLookup -->  "-ejbService" EjbService
+BusinessDelegate -->  "-serviceType" ServiceType
+Client -->  "-businessDelegate" BusinessDelegate
+BusinessDelegate -->  "-businessService" BusinessService
+BusinessDelegate -->  "-lookupService" BusinessLookup
+BusinessLookup -->  "-jmsService" JmsService
+EjbService ..|> BusinessService 
+JmsService ..|> BusinessService 
+@enduml

business-delegate/pom.xml

@@ -1,36 +1,28 @@
 <?xml version="1.0"?>
-<!--
-
-    The MIT License
-    Copyright © 2014-2019 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
--->
+<!-- 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. -->
 <project
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
-	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.22.0-SNAPSHOT</version>
+		<version>1.23.0-SNAPSHOT</version>
 	</parent>
 	<artifactId>business-delegate</artifactId>
 	<dependencies>
@@ -45,4 +37,23 @@
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.business.delegate.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>

business-delegate/src/main/java/com/iluwatar/business/delegate/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+module com.iluwatar.business.delegate {
+	requires org.slf4j;
+}

bytecode/README.md

@@ -5,13 +5,15 @@ folder: bytecode
 permalink: /patterns/bytecode/
 categories: Behavioral
 tags:
- - Java
- - Difficulty-Beginner
+ - Game programming
 ---
 
 ## Intent
 Allows to encode behaviour as instructions for virtual machine.
 
+## Class diagram
+![alt text](./etc/bytecode.urm.png "Bytecode class diagram")
+
 ## Applicability
 Use the Bytecode pattern when you have a lot of behavior you need to define and your
 game’s implementation language isn’t a good fit because:

bytecode/etc/bytecode.urm.puml

@@ -0,0 +1,69 @@
+@startuml
+package com.iluwatar.bytecode {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    - interpretInstruction(instruction : String, vm : VirtualMachine) {static}
+    + main(args : String[]) {static}
+  }
+  enum Instruction {
+    + ADD {static}
+    + DIVIDE {static}
+    + GET_AGILITY {static}
+    + GET_HEALTH {static}
+    + GET_WISDOM {static}
+    + LITERAL {static}
+    + PLAY_SOUND {static}
+    + SET_AGILITY {static}
+    + SET_HEALTH {static}
+    + SET_WISDOM {static}
+    + SPAWN_PARTICLES {static}
+    - value : int
+    + getInstruction(value : int) : Instruction {static}
+    + getIntValue() : int
+    + valueOf(name : String) : Instruction {static}
+    + values() : Instruction[] {static}
+  }
+  class VirtualMachine {
+    - stack : Stack<Integer>
+    - wizards : Wizard[]
+    + VirtualMachine()
+    + execute(bytecode : int[])
+    + getAgility(wizard : int) : int
+    + getHealth(wizard : int) : int
+    + getStack() : Stack<Integer>
+    + getWisdom(wizard : int) : int
+    + getWizards() : Wizard[]
+    + setAgility(wizard : int, amount : int)
+    + setHealth(wizard : int, amount : int)
+    + setWisdom(wizard : int, amount : int)
+  }
+  class Wizard {
+    - LOGGER : Logger {static}
+    - agility : int
+    - health : int
+    - numberOfPlayedSounds : int
+    - numberOfSpawnedParticles : int
+    - wisdom : int
+    + Wizard()
+    + getAgility() : int
+    + getHealth() : int
+    + getNumberOfPlayedSounds() : int
+    + getNumberOfSpawnedParticles() : int
+    + getWisdom() : int
+    + playSound()
+    + setAgility(agility : int)
+    + setHealth(health : int)
+    + setWisdom(wisdom : int)
+    + spawnParticles()
+  }
+}
+package com.iluwatar.bytecode.util {
+  class InstructionConverterUtil {
+    + InstructionConverterUtil()
+    + convertToByteCode(instructions : String) : int[] {static}
+    - isValidInstruction(instruction : String) : boolean {static}
+    - isValidInt(value : String) : boolean {static}
+  }
+}
+@enduml

bytecode/pom.xml

@@ -1,45 +1,56 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    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.
-
--->
+<!-- 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. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <parent>
-        <artifactId>java-design-patterns</artifactId>
-        <groupId>com.iluwatar</groupId>
-        <version>1.22.0-SNAPSHOT</version>
-    </parent>
-    <modelVersion>4.0.0</modelVersion>
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>java-design-patterns</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
 
-    <artifactId>bytecode</artifactId>
-    <dependencies>
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-engine</artifactId>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+	<artifactId>bytecode</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.bytecode.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 
 </project>

caching/README.md

@@ -3,10 +3,8 @@ layout: pattern
 title: Caching
 folder: caching
 permalink: /patterns/caching/
-categories: Other
+categories: Behavioral
 tags:
- - Java
- - Difficulty-Intermediate
  - Performance
 ---
 
@@ -15,6 +13,7 @@ To avoid expensive re-acquisition of resources by not releasing
 the resources immediately after their use. The resources retain their identity, are kept in some
 fast-access storage, and are re-used to avoid having to acquire them again.
 
+## Class diagram
 ![alt text](./etc/caching.png "Caching")
 
 ## Applicability

caching/etc/caching.urm.puml

@@ -0,0 +1,119 @@
+@startuml
+package com.iluwatar.caching.constants {
+  class CachingConstants {
+    + ADD_INFO : String {static}
+    + USER_ACCOUNT : String {static}
+    + USER_ID : String {static}
+    + USER_NAME : String {static}
+    + CachingConstants()
+  }
+}
+package com.iluwatar.caching {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+    + useCacheAsideStategy()
+    + useReadAndWriteThroughStrategy()
+    + useReadThroughAndWriteAroundStrategy()
+    + useReadThroughAndWriteBehindStrategy()
+  }
+  class AppManager {
+    - cachingPolicy : CachingPolicy {static}
+    - AppManager()
+    + find(userId : String) : UserAccount {static}
+    - findAside(userId : String) : UserAccount {static}
+    + initCacheCapacity(capacity : int) {static}
+    + initCachingPolicy(policy : CachingPolicy) {static}
+    + initDb(useMongoDb : boolean) {static}
+    + printCacheContent() : String {static}
+    + save(userAccount : UserAccount) {static}
+    - saveAside(userAccount : UserAccount) {static}
+  }
+  class CacheStore {
+    - LOGGER : Logger {static}
+    - cache : LruCache {static}
+    - CacheStore()
+    + clearCache() {static}
+    + flushCache() {static}
+    + get(userId : String) : UserAccount {static}
+    + initCapacity(capacity : int) {static}
+    + invalidate(userId : String) {static}
+    + print() : String {static}
+    + readThrough(userId : String) : UserAccount {static}
+    + readThroughWithWriteBackPolicy(userId : String) : UserAccount {static}
+    + set(userId : String, userAccount : UserAccount) {static}
+    + writeAround(userAccount : UserAccount) {static}
+    + writeBehind(userAccount : UserAccount) {static}
+    + writeThrough(userAccount : UserAccount) {static}
+  }
+  enum CachingPolicy {
+    + AROUND {static}
+    + ASIDE {static}
+    + BEHIND {static}
+    + THROUGH {static}
+    - policy : String
+    + getPolicy() : String
+    + valueOf(name : String) : CachingPolicy {static}
+    + values() : CachingPolicy[] {static}
+  }
+  class DbManager {
+    - db : MongoDatabase {static}
+    - mongoClient : MongoClient {static}
+    - useMongoDB : boolean {static}
+    - virtualDB : Map<String, UserAccount> {static}
+    - DbManager()
+    + connect() {static}
+    + createVirtualDb() {static}
+    + readFromDb(userId : String) : UserAccount {static}
+    + updateDb(userAccount : UserAccount) {static}
+    + upsertDb(userAccount : UserAccount) {static}
+    + writeToDb(userAccount : UserAccount) {static}
+  }
+  class LruCache {
+    - LOGGER : Logger {static}
+    ~ cache : Map<String, Node>
+    ~ capacity : int
+    ~ end : Node
+    ~ head : Node
+    + LruCache(capacity : int)
+    + clear()
+    + contains(userId : String) : boolean
+    + get(userId : String) : UserAccount
+    + getCacheDataInListForm() : List<UserAccount>
+    + getLruData() : UserAccount
+    + invalidate(userId : String)
+    + isFull() : boolean
+    + remove(node : Node)
+    + set(userId : String, userAccount : UserAccount)
+    + setCapacity(newCapacity : int)
+    + setHead(node : Node)
+  }
+  ~class Node {
+    ~ next : Node
+    ~ previous : Node
+    ~ userAccount : UserAccount
+    ~ userId : String
+    + Node(this$0 : String, userId : UserAccount)
+  }
+  class UserAccount {
+    - additionalInfo : String
+    - userId : String
+    - userName : String
+    + UserAccount(userId : String, userName : String, additionalInfo : String)
+    + getAdditionalInfo() : String
+    + getUserId() : String
+    + getUserName() : String
+    + setAdditionalInfo(additionalInfo : String)
+    + setUserId(userId : String)
+    + setUserName(userName : String)
+    + toString() : String
+  }
+}
+Node --+ LruCache
+LruCache -->  "-head" Node
+Node -->  "-previous" Node
+AppManager -->  "-cachingPolicy" CachingPolicy
+Node -->  "-userAccount" UserAccount
+CacheStore -->  "-cache" LruCache
+@enduml

caching/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
   <artifactId>caching</artifactId>
   <dependencies>
@@ -41,7 +41,7 @@
     <dependency>
       <groupId>org.mongodb</groupId>
       <artifactId>mongodb-driver</artifactId>
-      <version>3.0.4</version>
+      <version>3.12.1</version>
     </dependency>
     <dependency>
       <groupId>org.mongodb</groupId>
@@ -69,6 +69,21 @@
           <skipTests>false</skipTests>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.caching.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
     </plugins>
   </build>
 </project>

callback/README.md

@@ -3,12 +3,9 @@ layout: pattern
 title: Callback
 folder: callback
 permalink: /patterns/callback/
-categories: Other
+categories: Idiom
 tags:
- - Java
- - Difficulty-Beginner
- - Functional
- - Idiom
+ - Reactive
 ---
 
 ## Intent
@@ -16,6 +13,7 @@ Callback is a piece of executable code that is passed as an
 argument to other code, which is expected to call back (execute) the argument
 at some convenient time.
 
+## Class diagram
 ![alt text](./etc/callback.png "Callback")
 
 ## Applicability

callback/etc/callback.urm.puml

@@ -0,0 +1,28 @@
+@startuml
+package com.iluwatar.callback {
+  class App {
+    - LOGGER : Logger {static}
+    - App()
+    + main(args : String[]) {static}
+  }
+  interface Callback {
+    + call() {abstract}
+  }
+  class LambdasApp {
+    - LOGGER : Logger {static}
+    - LambdasApp()
+    + main(args : String[]) {static}
+  }
+  class SimpleTask {
+    - LOGGER : Logger {static}
+    + SimpleTask()
+    + execute()
+  }
+  abstract class Task {
+    + Task()
+    + execute() {abstract}
+    ~ executeWith(callback : Callback)
+  }
+}
+SimpleTask --|> Task 
+@enduml

callback/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
   <artifactId>callback</artifactId>
   <dependencies>
@@ -39,4 +39,23 @@
       <scope>test</scope>
     </dependency>
   </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.callback.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
 </project>

callback/src/main/java/com/iluwatar/callback/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+module com.iluwatar.callback {
+	requires org.slf4j;
+}

chain/README.md

@@ -5,9 +5,7 @@ folder: chain
 permalink: /patterns/chain/
 categories: Behavioral
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Intent
@@ -141,6 +139,9 @@ king.makeRequest(new Request(RequestType.TORTURE_PRISONER, "torture prisoner"));
 king.makeRequest(new Request(RequestType.COLLECT_TAX, "collect tax")); // Orc soldier handling request "collect tax"
 ```
 
+## Class diagram
+![alt text](./etc/chain.urm.png "Chain of Responsibility class diagram")
+
 ## Applicability
 Use Chain of Responsibility when
 

chain/etc/chain.urm.puml

@@ -0,0 +1,61 @@
+@startuml
+package com.iluwatar.chain {
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class OrcCommander {
+    + OrcCommander(handler : RequestHandler)
+    + handleRequest(req : Request)
+    + toString() : String
+  }
+  class OrcKing {
+    - chain : RequestHandler
+    + OrcKing()
+    - buildChain()
+    + makeRequest(req : Request)
+  }
+  class OrcOfficer {
+    + OrcOfficer(handler : RequestHandler)
+    + handleRequest(req : Request)
+    + toString() : String
+  }
+  class OrcSoldier {
+    + OrcSoldier(handler : RequestHandler)
+    + handleRequest(req : Request)
+    + toString() : String
+  }
+  class Request {
+    - handled : boolean
+    - requestDescription : String
+    - requestType : RequestType
+    + Request(requestType : RequestType, requestDescription : String)
+    + getRequestDescription() : String
+    + getRequestType() : RequestType
+    + isHandled() : boolean
+    + markHandled()
+    + toString() : String
+  }
+  abstract class RequestHandler {
+    - LOGGER : Logger {static}
+    - next : RequestHandler
+    + RequestHandler(next : RequestHandler)
+    + handleRequest(req : Request)
+    # printHandling(req : Request)
+    + toString() : String {abstract}
+  }
+  enum RequestType {
+    + COLLECT_TAX {static}
+    + DEFEND_CASTLE {static}
+    + TORTURE_PRISONER {static}
+    + valueOf(name : String) : RequestType {static}
+    + values() : RequestType[] {static}
+  }
+}
+OrcKing -->  "-chain" RequestHandler
+RequestHandler -->  "-next" RequestHandler
+Request -->  "-requestType" RequestType
+OrcCommander --|> RequestHandler 
+OrcOfficer --|> RequestHandler 
+OrcSoldier --|> RequestHandler 
+@enduml

chain/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
   <artifactId>chain</artifactId>
   <dependencies>
@@ -39,4 +39,23 @@
       <scope>test</scope>
     </dependency>
   </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.chain.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
 </project>

chain/src/main/java/com/iluwatar/chain/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+module com.iluwatar.chain {
+	requires org.slf4j;
+}

circuit-breaker/README.md

@@ -3,11 +3,10 @@ layout: pattern
 title: Circuit Breaker
 folder: circuit-breaker
 permalink: /patterns/circuit-breaker/
-categories: Other
+categories: Behavioral
 tags:
- - Java
  - Performance
- - Difficulty-Intermediate
+ - Decoupling
 ---
 
 ## Intent
@@ -165,6 +164,8 @@ How does the above pattern prevent failures? Let's understand via this finite st
 - If the number of failures cross a certain threshold, we move to the **open** state, which acts just like an open circuit and prevents remote service calls from being made, thus saving resources. (Here, we return the response called ```stale response from API```)
 - Once we exceed the retry timeout period, we move to the **half-open** state and make another call to the remote service again to check if the service is working so that we can serve fresh content. A *failure* sets it back to **open** state and another attempt is made after retry timeout period, while a *success* sets it to **closed** state so that everything starts working normally again. 
 
+## Class diagram
+![alt text](./etc/circuit-breaker.urm.png "Circuit Breaker class diagram")
 
 ## Applicability
 Use the Circuit Breaker pattern when
@@ -177,6 +178,7 @@ Use the Circuit Breaker pattern when
 - [Retry Pattern](https://github.com/iluwatar/java-design-patterns/tree/master/retry)
 
 ## Real world examples
+
 * [Spring Circuit Breaker module](https://spring.io/guides/gs/circuit-breaker)
 * [Netflix Hystrix API](https://github.com/Netflix/Hystrix)
 

circuit-breaker/etc/circuit-breaker.urm.puml

@@ -0,0 +1,44 @@
+@startuml
+package com.iluwatar.circuitbreaker {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+  }
+  class CircuitBreaker {
+    ~ failureCount : int
+    - failureThreshold : int
+    - futureTime : long
+    ~ lastFailureTime : long
+    - retryTimePeriod : long
+    - state : State
+    - timeout : long
+    ~ CircuitBreaker(timeout : long, failureThreshold : int, retryTimePeriod : long)
+    + call(serviceToCall : String, serverStartTime : long) : String
+    + getState() : String
+    - recordFailure()
+    - reset()
+    # setState()
+    + setStateForBypass(state : State)
+  }
+  class DelayedService {
+    - delay : int
+    + DelayedService()
+    + DelayedService(delay : int)
+    + response(serverStartTime : long) : String
+  }
+  class MonitoringService {
+    + MonitoringService()
+    + localResourceResponse() : String
+    + remoteResourceResponse(circuitBreaker : CircuitBreaker, serverStartTime : long) : String
+  }
+  enum State {
+    + CLOSED {static}
+    + HALF_OPEN {static}
+    + OPEN {static}
+    + valueOf(name : String) : State {static}
+    + values() : State[] {static}
+  }
+}
+CircuitBreaker -->  "-state" State
+@enduml

circuit-breaker/pom.xml

@@ -27,7 +27,7 @@
     <parent>
         <groupId>com.iluwatar</groupId>
         <artifactId>java-design-patterns</artifactId>
-        <version>1.22.0-SNAPSHOT</version>
+        <version>1.23.0-SNAPSHOT</version>
     </parent>
     <artifactId>circuit-breaker</artifactId>
     <dependencies>
@@ -37,4 +37,23 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+    <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.circuitbreaker.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
 </project>

collection-pipeline/README.md

@@ -3,17 +3,16 @@ layout: pattern
 title: Collection Pipeline
 folder: collection-pipeline
 permalink: /patterns/collection-pipeline/
-categories: Other
+categories: Functional
 tags:
- - Java
- - Difficulty-Beginner
- - Functional
+ - Reactive
 ---
 
 ## Intent
 Collection Pipeline introduces Function Composition and Collection Pipeline, two functional-style patterns that you can combine to iterate collections in your code. 
 In functional programming, it's common to sequence complex operations through a series of smaller modular functions or operations. The series is called a composition of functions, or a function composition. When a collection of data flows through a function composition, it becomes a collection pipeline. Function Composition and Collection Pipeline are two design patterns frequently used in functional-style programming.
 
+## Class diagram
 ![alt text](./etc/collection-pipeline.png "Collection Pipeline")
 
 ## Applicability
@@ -27,4 +26,4 @@ Use the Collection Pipeline pattern when
 
 * [Function composition and the Collection Pipeline pattern](https://www.ibm.com/developerworks/library/j-java8idioms2/index.html)
 * [Martin Fowler](https://martinfowler.com/articles/collection-pipeline/)
-* [Java8 Streams](https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html)
+* [Java8 Streams](https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html)

collection-pipeline/etc/collection-pipeline.urm.puml

@@ -0,0 +1,52 @@
+@startuml
+package com.iluwatar.collectionpipeline {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+  }
+  class Car {
+    - category : Category
+    - make : String
+    - model : String
+    - year : int
+    + Car(make : String, model : String, yearOfMake : int, category : Category)
+    + equals(obj : Object) : boolean
+    + getCategory() : Category
+    + getMake() : String
+    + getModel() : String
+    + getYear() : int
+    + hashCode() : int
+  }
+  class CarFactory {
+    - CarFactory()
+    + createCars() : List<Car> {static}
+  }
+  enum Category {
+    + CONVERTIBLE {static}
+    + JEEP {static}
+    + SEDAN {static}
+    + valueOf(name : String) : Category {static}
+    + values() : Category[] {static}
+  }
+  class FunctionalProgramming {
+    - FunctionalProgramming()
+    + getGroupingOfCarsByCategory(cars : List<Car>) : Map<Category, List<Car>> {static}
+    + getModelsAfter2000(cars : List<Car>) : List<String> {static}
+    + getSedanCarsOwnedSortedByDate(persons : List<Person>) : List<Car> {static}
+  }
+  class ImperativeProgramming {
+    - ImperativeProgramming()
+    + getGroupingOfCarsByCategory(cars : List<Car>) : Map<Category, List<Car>> {static}
+    + getModelsAfter2000(cars : List<Car>) : List<String> {static}
+    + getSedanCarsOwnedSortedByDate(persons : List<Person>) : List<Car> {static}
+  }
+  class Person {
+    - cars : List<Car>
+    + Person(cars : List<Car>)
+    + getCars() : List<Car>
+  }
+}
+Person -->  "-cars" Car
+Car -->  "-category" Category
+@enduml

collection-pipeline/pom.xml

@@ -27,7 +27,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
   <artifactId>collection-pipeline</artifactId>
   <dependencies>
@@ -37,4 +37,23 @@
       <scope>test</scope>
     </dependency>
   </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.collectionpipeline.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
 </project>

collection-pipeline/src/main/java/com/iluwatar/collectionpipeline/ImperativeProgramming.java

@@ -23,12 +23,12 @@
 
 package com.iluwatar.collectionpipeline;
 
-import java.util.Collection;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.stream.Collectors;
 
 /**
  * Imperative-style programming to iterate over the list and get the names of cars made later than
@@ -57,11 +57,27 @@ public class ImperativeProgramming {
    * @return {@link List} of {@link String} of car models built after year 2000
    */
   public static List<String> getModelsAfter2000(List<Car> cars) {
-    return cars.stream()
-        .filter(car -> car.getYear() > 2000)
-        .sorted(Comparator.comparingInt(Car::getYear))
-        .map(Car::getModel)
-        .collect(Collectors.toList());
+    List<Car> carsSortedByYear = new ArrayList<>();
+
+    for (Car car : cars) {
+      if (car.getYear() > 2000) {
+        carsSortedByYear.add(car);
+      }
+    }
+
+    Collections.sort(carsSortedByYear, new Comparator<Car>() {
+      @Override
+      public int compare(Car car1, Car car2) {
+        return car1.getYear() - car2.getYear();
+      }
+    });
+
+    List<String> models = new ArrayList<>();
+    for (Car car : carsSortedByYear) {
+      models.add(car.getModel());
+    }
+
+    return models;
   }
 
   /**
@@ -71,7 +87,17 @@ public class ImperativeProgramming {
    * @return {@link Map} with category as key and cars belonging to that category as value
    */
   public static Map<Category, List<Car>> getGroupingOfCarsByCategory(List<Car> cars) {
-    return cars.stream().collect(Collectors.groupingBy(Car::getCategory));
+    Map<Category, List<Car>> groupingByCategory = new HashMap<>();
+    for (Car car : cars) {
+      if (groupingByCategory.containsKey(car.getCategory())) {
+        groupingByCategory.get(car.getCategory()).add(car);
+      } else {
+        List<Car> categoryCars = new ArrayList<>();
+        categoryCars.add(car);
+        groupingByCategory.put(car.getCategory(), categoryCars);
+      }
+    }
+    return groupingByCategory;
   }
 
   /**
@@ -82,11 +108,25 @@ public class ImperativeProgramming {
    * @return {@link List} of {@link Car} to belonging to the group
    */
   public static List<Car> getSedanCarsOwnedSortedByDate(List<Person> persons) {
-    return persons.stream()
-        .map(Person::getCars)
-        .flatMap(Collection::stream)
-        .filter(car -> car.getCategory() == Category.SEDAN)
-        .sorted(Comparator.comparingInt(Car::getYear))
-        .collect(Collectors.toList());
+    List<Car> cars = new ArrayList<>();
+    for (Person person : persons) {
+      cars.addAll(person.getCars());
+    }
+
+    List<Car> sedanCars = new ArrayList<>();
+    for (Car car : cars) {
+      if (Category.SEDAN.equals(car.getCategory())) {
+        sedanCars.add(car);
+      }
+    }
+
+    sedanCars.sort(new Comparator<Car>() {
+      @Override
+      public int compare(Car o1, Car o2) {
+        return o1.getYear() - o2.getYear();
+      }
+    });
+
+    return sedanCars;
   }
 }

collection-pipeline/src/main/java/com/iluwatar/collectionpipeline/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+module com.iluwatar.collectionpipeline {
+	requires org.slf4j;
+}

combinator/README.md

@@ -0,0 +1,36 @@
+---
+layout: pattern
+title: Combinator
+folder: combinator
+permalink: /patterns/combinator/
+categories: Idiom
+tags:
+ - Reactive
+---
+
+## Also known as
+Composition pattern
+
+## Intent
+The functional pattern representing a style of organizing libraries centered around the idea of combining functions.  
+Putting it simply, there is some type T, some functions for constructing "primitive" values of type T, 
+and some "combinators" which can combine values of type T in various ways to build up more complex values of type T.
+
+## Class diagram
+![alt text](./etc/combinator.urm.png "Combinator class diagram")
+
+## Applicability
+Use the combinator pattern when:
+
+- You are able to create a more complex value from more plain values but having the same type(a combination of them)
+
+## Real world examples
+
+- java.util.function.Function#compose
+- java.util.function.Function#andThen
+
+## Credits
+
+- [Example for java](https://gtrefs.github.io/code/combinator-pattern/)
+- [Combinator pattern](https://wiki.haskell.org/Combinator_pattern)
+- [Combinatory logic](https://wiki.haskell.org/Combinatory_logic)

combinator/etc/combinator.urm.puml

@@ -0,0 +1,26 @@
+@startuml
+package com.iluwatar.combinator {
+  class CombinatorApp {
+    - LOGGER : Logger {static}
+    + CombinatorApp()
+    + main(args : String[]) {static}
+    - text() : String {static}
+  }
+  interface Finder {
+    + and(andFinder : Finder) : Finder
+    + contains(word : String) : Finder {static}
+    + find(String) : List<String> {abstract}
+    + not(notFinder : Finder) : Finder
+    + or(orFinder : Finder) : Finder
+  }
+  class Finders {
+    - Finders()
+    + advancedFinder(query : String, orQuery : String, notQuery : String) : Finder {static}
+    + expandedFinder(queries : String[]) : Finder {static}
+    + filteredFinder(query : String, excludeQueries : String[]) : Finder {static}
+    - identMult() : Finder {static}
+    - identSum() : Finder {static}
+    + specializedFinder(queries : String[]) : Finder {static}
+  }
+}
+@enduml

combinator/pom.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0"?>
+<!--
+
+    The MIT License
+    Copyright © 2014-2019 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.iluwatar</groupId>
+    <artifactId>java-design-patterns</artifactId>
+    <version>1.23.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>combinator</artifactId>
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+</project>

combinator/src/main/java/com/iluwatar/combinator/CombinatorApp.java

@@ -0,0 +1,92 @@
+/*
+ * 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.combinator;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * The functional pattern representing a style of organizing libraries
+ * centered around the idea of combining functions.
+ * Putting it simply, there is some type T, some functions
+ * for constructing "primitive" values of type T,
+ * and some "combinators" which can combine values of type T
+ * in various ways to build up more complex values of type T.
+ * The class {@link Finder} defines a simple function {@link Finder#find(String)}
+ * and connected functions
+ * {@link Finder#or(Finder)},
+ * {@link Finder#not(Finder)},
+ * {@link Finder#and(Finder)}
+ * Using them the became possible to get more complex functions {@link Finders}
+ */
+public class CombinatorApp {
+
+  /**
+   * Logger.
+   */
+  private static final Logger LOGGER = LoggerFactory.getLogger(CombinatorApp.class);
+
+  /**
+   * main.
+   * @param args args
+   */
+  public static void main(String[] args) {
+    var queriesOr = new String[]{"many", "Annabel"};
+    var finder = Finders.expandedFinder(queriesOr);
+    var res = finder.find(text());
+    LOGGER.info("the result of expanded(or) query[{}] is {}", queriesOr, res);
+
+    var queriesAnd = new String[]{"Annabel", "my"};
+    finder = Finders.specializedFinder(queriesAnd);
+    res = finder.find(text());
+    LOGGER.info("the result of specialized(and) query[{}] is {}", queriesAnd, res);
+
+    finder = Finders.advancedFinder("it was","kingdom","sea");
+    res = finder.find(text());
+    LOGGER.info("the result of advanced query is {}", res);
+
+    res = Finders.filteredFinder(" was ", "many", "child").find(text());
+    LOGGER.info("the result of filtered query is {}", res);
+
+
+  }
+
+  private static String text() {
+    return
+        "It was many and many a year ago,\n"
+            + "In a kingdom by the sea,\n"
+            + "That a maiden there lived whom you may know\n"
+            + "By the name of ANNABEL LEE;\n"
+            + "And this maiden she lived with no other thought\n"
+            + "Than to love and be loved by me.\n"
+            + "I was a child and she was a child,\n"
+            + "In this kingdom by the sea;\n"
+            + "But we loved with a love that was more than love-\n"
+            + "I and my Annabel Lee;\n"
+            + "With a love that the winged seraphs of heaven\n"
+            + "Coveted her and me.";
+  }
+
+}

combinator/src/main/java/com/iluwatar/combinator/Finder.java

@@ -0,0 +1,93 @@
+/*
+ * 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.combinator;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * Functional interface to find lines in text.
+ */
+public interface Finder {
+
+  /**
+   * The function to find lines in text.
+   * @param text full tet
+   * @return result of searching
+   */
+  List<String> find(String text);
+
+  /**
+   * Simple implementation of function {@link #find(String)}.
+   * @param word for searching
+   * @return this
+   */
+  static Finder contains(String word) {
+    return txt -> Stream.of(txt.split("\n"))
+        .filter(line -> line.toLowerCase().contains(word.toLowerCase()))
+        .collect(Collectors.toList());
+  }
+
+  /**
+   * combinator not.
+   * @param notFinder finder to combine
+   * @return new finder including previous finders
+   */
+  default Finder not(Finder notFinder) {
+    return txt -> {
+      List<String> res = this.find(txt);
+      res.removeAll(notFinder.find(txt));
+      return res;
+    };
+  }
+
+  /**
+   * combinator or.
+   * @param orFinder finder to combine
+   * @return new finder including previous finders
+   */
+  default Finder or(Finder orFinder) {
+    return txt -> {
+      List<String> res = this.find(txt);
+      res.addAll(orFinder.find(txt));
+      return res;
+    };
+  }
+
+  /**
+   * combinator or.
+   * @param andFinder finder to combine
+   * @return new finder including previous finders
+   */
+  default Finder and(Finder andFinder) {
+    return
+        txt -> this
+            .find(txt)
+            .stream()
+            .flatMap(line -> andFinder.find(line).stream())
+            .collect(Collectors.toList());
+  }
+
+}

combinator/src/main/java/com/iluwatar/combinator/Finders.java

@@ -0,0 +1,103 @@
+/*
+ * 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.combinator;
+
+import java.util.ArrayList;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * Complex finders consisting of simple finder.
+ */
+public class Finders {
+  private Finders() {
+  }
+
+
+  /**
+   * Finder to find a complex query.
+   * @param query to find
+   * @param orQuery alternative to find
+   * @param notQuery exclude from search
+   * @return new finder
+   */
+  public static Finder advancedFinder(String query, String orQuery, String notQuery) {
+    return
+        Finder.contains(query)
+            .or(Finder.contains(orQuery))
+            .not(Finder.contains(notQuery));
+  }
+
+  /**
+   * Filtered finder looking a query with excluded queries as well.
+   * @param query to find
+   * @param excludeQueries to exclude
+   * @return new finder
+   */
+  public static Finder filteredFinder(String query, String... excludeQueries) {
+    var finder = Finder.contains(query);
+
+    for (String q : excludeQueries) {
+      finder = finder.not(Finder.contains(q));
+    }
+    return finder;
+
+  }
+
+  /**
+   * Specialized query. Every next query is looked in previous result.
+   * @param queries array with queries
+   * @return new finder
+   */
+  public static Finder specializedFinder(String... queries) {
+    var finder = identMult();
+
+    for (String query : queries) {
+      finder = finder.and(Finder.contains(query));
+    }
+    return finder;
+  }
+
+  /**
+   * Expanded query. Looking for alternatives.
+   * @param queries array with queries.
+   * @return new finder
+   */
+  public static Finder expandedFinder(String... queries) {
+    var finder = identSum();
+
+    for (String query : queries) {
+      finder = finder.or(Finder.contains(query));
+    }
+    return finder;
+  }
+
+  private static Finder identMult() {
+    return txt -> Stream.of(txt.split("\n")).collect(Collectors.toList());
+  }
+
+  private static Finder identSum() {
+    return txt -> new ArrayList<>();
+  }
+}

combinator/src/test/java/com/iluwatar/combinator/CombinatorAppTest.java

@@ -0,0 +1,36 @@
+/*
+ * 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.combinator;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class CombinatorAppTest {
+
+  @Test
+  public void main() {
+    CombinatorApp.main(new String[]{});
+  }
+}

combinator/src/test/java/com/iluwatar/combinator/FinderTest.java

@@ -0,0 +1,44 @@
+/*
+ * 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.combinator;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.*;
+
+public class FinderTest {
+
+  @Test
+  public void contains() {
+    var example = "the first one \nthe second one \n";
+
+    var result = Finder.contains("second").find(example);
+    Assert.assertEquals(result.size(),1);
+    Assert.assertEquals(result.get(0),"the second one ");
+  }
+
+}

combinator/src/test/java/com/iluwatar/combinator/FindersTest.java

@@ -0,0 +1,83 @@
+/*
+ * 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.combinator;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.List;
+
+import static com.iluwatar.combinator.Finders.*;
+import static org.junit.Assert.*;
+
+public class FindersTest {
+
+  @Test
+  public void advancedFinderTest() {
+    var res = advancedFinder("it was","kingdom","sea").find(text());
+    Assert.assertEquals(res.size(),1);
+    Assert.assertEquals(res.get(0),"It was many and many a year ago,");
+  }
+
+  @Test
+  public void filteredFinderTest() {
+    var res = filteredFinder(" was ", "many", "child").find(text());
+    Assert.assertEquals(res.size(),1);
+    Assert.assertEquals(res.get(0),"But we loved with a love that was more than love-");
+  }
+
+  @Test
+  public void specializedFinderTest() {
+    var res = specializedFinder("love","heaven").find(text());
+    Assert.assertEquals(res.size(),1);
+    Assert.assertEquals(res.get(0),"With a love that the winged seraphs of heaven");
+  }
+
+  @Test
+  public void expandedFinderTest() {
+    var res = expandedFinder("It was","kingdom").find(text());
+    Assert.assertEquals(res.size(),3);
+    Assert.assertEquals(res.get(0),"It was many and many a year ago,");
+    Assert.assertEquals(res.get(1),"In a kingdom by the sea,");
+    Assert.assertEquals(res.get(2),"In this kingdom by the sea;");
+  }
+
+
+  private String text(){
+    return
+        "It was many and many a year ago,\n"
+            + "In a kingdom by the sea,\n"
+            + "That a maiden there lived whom you may know\n"
+            + "By the name of ANNABEL LEE;\n"
+            + "And this maiden she lived with no other thought\n"
+            + "Than to love and be loved by me.\n"
+            + "I was a child and she was a child,\n"
+            + "In this kingdom by the sea;\n"
+            + "But we loved with a love that was more than love-\n"
+            + "I and my Annabel Lee;\n"
+            + "With a love that the winged seraphs of heaven\n"
+            + "Coveted her and me.";
+  }
+
+}

command/README.md

@@ -5,10 +5,7 @@ folder: command
 permalink: /patterns/command/
 categories: Behavioral
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
- - Functional
+ - Gang of Four
 ---
 
 ## Also known as
@@ -19,6 +16,7 @@ Encapsulate a request as an object, thereby letting you
 parameterize clients with different requests, queue or log requests, and
 support undoable operations.
 
+## Class diagram
 ![alt text](./etc/command.png "Command")
 
 ## Applicability

command/etc/command.urm.puml

@@ -0,0 +1,83 @@
+@startuml
+package com.iluwatar.command {
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  abstract class Command {
+    + Command()
+    + execute(Target) {abstract}
+    + redo() {abstract}
+    + toString() : String {abstract}
+    + undo() {abstract}
+  }
+  class Goblin {
+    + Goblin()
+    + toString() : String
+  }
+  class InvisibilitySpell {
+    - target : Target
+    + InvisibilitySpell()
+    + execute(target : Target)
+    + redo()
+    + toString() : String
+    + undo()
+  }
+  class ShrinkSpell {
+    - oldSize : Size
+    - target : Target
+    + ShrinkSpell()
+    + execute(target : Target)
+    + redo()
+    + toString() : String
+    + undo()
+  }
+  enum Size {
+    + NORMAL {static}
+    + SMALL {static}
+    - title : String
+    + toString() : String
+    + valueOf(name : String) : Size {static}
+    + values() : Size[] {static}
+  }
+  abstract class Target {
+    - LOGGER : Logger {static}
+    - size : Size
+    - visibility : Visibility
+    + Target()
+    + getSize() : Size
+    + getVisibility() : Visibility
+    + printStatus()
+    + setSize(size : Size)
+    + setVisibility(visibility : Visibility)
+    + toString() : String {abstract}
+  }
+  enum Visibility {
+    + INVISIBLE {static}
+    + VISIBLE {static}
+    - title : String
+    + toString() : String
+    + valueOf(name : String) : Visibility {static}
+    + values() : Visibility[] {static}
+  }
+  class Wizard {
+    - LOGGER : Logger {static}
+    - redoStack : Deque<Command>
+    - undoStack : Deque<Command>
+    + Wizard()
+    + castSpell(command : Command, target : Target)
+    + redoLastSpell()
+    + toString() : String
+    + undoLastSpell()
+  }
+}
+Target -->  "-size" Size
+Wizard -->  "-undoStack" Command
+ShrinkSpell -->  "-oldSize" Size
+InvisibilitySpell -->  "-target" Target
+ShrinkSpell -->  "-target" Target
+Target -->  "-visibility" Visibility
+Goblin --|> Target 
+InvisibilitySpell --|> Command 
+ShrinkSpell --|> Command 
+@enduml

command/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.22.0-SNAPSHOT</version>
+    <version>1.23.0-SNAPSHOT</version>
   </parent>
   <artifactId>command</artifactId>
   <dependencies>
@@ -39,4 +39,23 @@
       <scope>test</scope>
     </dependency>
   </dependencies>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.command.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
 </project>

command/src/main/java/com/iluwatar/command/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * 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.
+ */
+
+module com.iluwatar.command {
+	requires org.slf4j;
+}

commander/README.md

@@ -3,16 +3,18 @@ layout: pattern
 title: Commander
 folder: commander
 permalink: /patterns/commander/
-categories: Other
+categories: Concurrency
 tags:
- - Java
- - Difficulty-Intermediate
+ - Cloud distributed
 ---
 
 ## Intent
 
 > Used to handle all problems that can be encountered when doing distributed transactions.
 
+## Class diagram
+![alt text](./etc/commander.urm.png "Commander class diagram")
+
 ## Applicability
 This pattern can be used when we need to make commits into 2 (or more) databases to complete transaction, which cannot be done atomically and can thereby create problems.
 
@@ -21,4 +23,5 @@ Handling distributed transactions can be tricky, but if we choose to not handle
 We need a mechanism in place which can handle these kinds of situations. We have to direct the order to either one of the services (in this example, shipping) and then add the order into the database of the other service (in this example, payment), since two databses cannot be updated atomically. If currently unable to do it, there should be a queue where this request can be queued, and there has to be a mechanism which allows for a failure in the queueing as well. All this needs to be done by constant retries while ensuring idempotence (even if the request is made several times, the change should only be applied once) by a commander class, to reach a state of eventual consistency.
 
 ## Credits
+
 * [https://www.grahamlea.com/2016/08/distributed-transactions-microservices-icebergs/]