Merge pull request #382 from Crossy147/master

issue #333 Factory-kit

factory-kit/etc/factory-kit.ucls

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<class-diagram version="1.1.9" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
+  realizations="true" associations="true" dependencies="false" nesting-relationships="true">  
+  <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+    sort-features="false" accessors="true" visibility="true">    
+    <attributes public="true" package="true" protected="true" private="true" static="true"/>    
+    <operations public="true" package="true" protected="true" private="true" static="true"/>  
+  </classifier-display>  
+  <association-display labels="true" multiplicity="true"/>
+</class-diagram>

factory-kit/index.md

@@ -0,0 +1,28 @@
+---
+layout: pattern
+title: Factory Kit
+folder: factory-kit
+permalink: /patterns/factory-kit/
+categories: Creational
+tags:
+ - Java
+ - Difficulty-Beginner
+ - Functional
+---
+
+## Intent
+Define a factory of immutable content with separated builder and factory interfaces.
+
+![alt text](./etc/factory-kit.png "Factory Kit")
+
+## Applicability
+Use the Factory Kit pattern when
+
+* a class can't anticipate the class of objects it must create
+* you just want a new instance of a custom builder instead of the global one
+* you explicitly want to define types of objects, that factory can build
+* you want a separated builder and creator interface
+
+## Credits
+
+* [Design Pattern Reloaded by Remi Forax: ](https://www.youtube.com/watch?v=-k2X7guaArU)

factory-kit/pom.xml

@@ -0,0 +1,48 @@
+<?xml version="1.0"?>
+<!--
+
+    The MIT License
+    Copyright (c) 2014 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    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>1.11.0-SNAPSHOT</version>
+    </parent>
+    <artifactId>factory-kit</artifactId>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

factory-kit/src/main/java/com/iluwatar/factorykit/App.java

@@ -0,0 +1,32 @@
+package com.iluwatar.factorykit;
+
+/**
+ * Factory-kit is a creational pattern which defines a factory of immutable content
+ * with separated builder and factory interfaces to deal with the problem of
+ * creating one of the objects specified directly in the factory-kit instance.
+ *
+ * <p>
+ * In the given example {@link WeaponFactory} represents the factory-kit, that contains
+ * four {@link Builder}s for creating new objects of
+ * the classes implementing {@link Weapon} interface.
+ * <br>Each of them can be called with {@link WeaponFactory#create(WeaponType)} method, with
+ * an input representing an instance of {@link WeaponType} that needs to
+ * be mapped explicitly with desired class type in the factory instance.
+ */
+public class App {
+  /**
+   * Program entry point.
+   *
+   * @param args @param args command line args
+   */
+  public static void main(String[] args) {
+    WeaponFactory factory = WeaponFactory.factory(builder -> {
+      builder.add(WeaponType.SWORD, Sword::new);
+      builder.add(WeaponType.AXE, Axe::new);
+      builder.add(WeaponType.SPEAR, Spear::new);
+      builder.add(WeaponType.BOW, Bow::new);
+    });
+    Weapon axe = factory.create(WeaponType.AXE);
+    System.out.println(axe);
+  }
+}

factory-kit/src/main/java/com/iluwatar/factorykit/Axe.java

@@ -0,0 +1,8 @@
+package com.iluwatar.factorykit;
+
+public class Axe implements Weapon {
+  @Override
+  public String toString() {
+    return "Axe";
+  }
+}

factory-kit/src/main/java/com/iluwatar/factorykit/Bow.java

@@ -0,0 +1,8 @@
+package com.iluwatar.factorykit;
+
+public class Bow implements Weapon {
+  @Override
+  public String toString() {
+    return "Bow";
+  }
+}

factory-kit/src/main/java/com/iluwatar/factorykit/Builder.java

@@ -0,0 +1,10 @@
+package com.iluwatar.factorykit;
+
+import java.util.function.Supplier;
+
+/**
+ * Functional interface that allows adding builder with name to the factory.
+ */
+public interface Builder {
+  void add(WeaponType name, Supplier<Weapon> supplier);
+}

factory-kit/src/main/java/com/iluwatar/factorykit/Spear.java

@@ -0,0 +1,8 @@
+package com.iluwatar.factorykit;
+
+public class Spear implements Weapon {
+  @Override
+  public String toString() {
+    return "Spear";
+  }
+}

factory-kit/src/main/java/com/iluwatar/factorykit/Sword.java

@@ -0,0 +1,8 @@
+package com.iluwatar.factorykit;
+
+public class Sword implements Weapon {
+  @Override
+  public String toString() {
+    return "Sword";
+  }
+}

factory-kit/src/main/java/com/iluwatar/factorykit/Weapon.java

@@ -0,0 +1,7 @@
+package com.iluwatar.factorykit;
+
+/**
+ * Interface representing weapon.
+ */
+public interface Weapon {
+}

factory-kit/src/main/java/com/iluwatar/factorykit/WeaponFactory.java

@@ -0,0 +1,33 @@
+package com.iluwatar.factorykit;
+
+import java.util.HashMap;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+
+/**
+ * Functional interface, an example of the factory-kit design pattern.
+ * <br>Instance created locally gives an opportunity to strictly define
+ * which objects types the instance of a factory will be able to create.
+ * <br>Factory is a placeholder for {@link Builder}s
+ * with {@link WeaponFactory#create(WeaponType)} method to initialize new objects.
+ */
+public interface WeaponFactory {
+
+  /**
+   * Creates an instance of the given type.
+   * @param name representing enum of an object type to be created.
+   * @return new instance of a requested class implementing {@link Weapon} interface.
+   */
+  Weapon create(WeaponType name);
+
+  /**
+   * Creates factory - placeholder for specified {@link Builder}s.
+   * @param consumer for the new builder to the factory.
+   * @return factory with specified {@link Builder}s
+   */
+  static WeaponFactory factory(Consumer<Builder> consumer) {
+    HashMap<WeaponType, Supplier<Weapon>> map = new HashMap<>();
+    consumer.accept(map::put);
+    return name -> map.get(name).get();
+  }
+}

factory-kit/src/main/java/com/iluwatar/factorykit/WeaponType.java

@@ -0,0 +1,8 @@
+package com.iluwatar.factorykit;
+
+/**
+ * Enumerates {@link Weapon} types
+ */
+public enum WeaponType {
+  SWORD, AXE, BOW, SPEAR
+}

factory-kit/src/test/java/com/iluwatar/factorykit/app/AppTest.java

@@ -0,0 +1,14 @@
+package com.iluwatar.factorykit.app;
+
+import com.iluwatar.factorykit.App;
+import org.junit.Test;
+
+public class AppTest {
+
+  @Test
+  public void test() {
+    String[] args = {};
+    App.main(args);
+  }
+}
+

factory-kit/src/test/java/com/iluwatar/factorykit/factorykit/FactoryKitTest.java

@@ -0,0 +1,59 @@
+package com.iluwatar.factorykit.factorykit;
+
+import com.iluwatar.factorykit.*;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+public class FactoryKitTest {
+
+  private WeaponFactory factory;
+
+  @Before
+  public void init() {
+    factory = WeaponFactory.factory(builder -> {
+      builder.add(WeaponType.SPEAR, Spear::new);
+      builder.add(WeaponType.AXE, Axe::new);
+      builder.add(WeaponType.SWORD, Sword::new);
+    });
+  }
+
+  /**
+   * Testing {@link WeaponFactory} to produce a SPEAR asserting that the Weapon is an instance of {@link Spear}
+   */
+  @Test
+  public void testSpearWeapon() {
+    Weapon weapon = factory.create(WeaponType.SPEAR);
+    verifyWeapon(weapon, Spear.class);
+  }
+
+  /**
+   * Testing {@link WeaponFactory} to produce a AXE asserting that the Weapon is an instance of {@link Axe}
+   */
+  @Test
+  public void testAxeWeapon() {
+    Weapon weapon = factory.create(WeaponType.AXE);
+    verifyWeapon(weapon, Axe.class);
+  }
+
+
+  /**
+   * Testing {@link WeaponFactory} to produce a SWORD asserting that the Weapon is an instance of {@link Sword}
+   */
+  @Test
+  public void testWeapon() {
+    Weapon weapon = factory.create(WeaponType.SWORD);
+    verifyWeapon(weapon, Sword.class);
+  }
+
+  /**
+   * This method asserts that the weapon object that is passed is an instance of the clazz
+   *
+   * @param weapon weapon object which is to be verified
+   * @param clazz  expected class of the weapon
+   */
+  private void verifyWeapon(Weapon weapon, Class clazz) {
+    assertTrue("Weapon must be an object of: " + clazz.getName(), clazz.isInstance(weapon));
+  }
+}

pom.xml

@@ -119,6 +119,7 @@
 		<module>publish-subscribe</module>
 		<module>delegation</module>
 		<module>event-driven-architecture</module>
+		<module>factory-kit</module>
 		<module>feature-toggle</module>
 		<module>value-object</module>
 	</modules>