added mediator sample

mediator/pom.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0"?>
+<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>1.0-SNAPSHOT</version>
+  </parent>
+  <groupId>com.iluwatar</groupId>
+  <artifactId>mediator</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <name>mediator</name>
+  <url>http://maven.apache.org</url>
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>3.8.1</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+</project>

mediator/src/main/java/com/iluwatar/Action.java

@@ -0,0 +1,28 @@
+package com.iluwatar;
+
+public enum Action {
+
+	HUNT, TALE, GOLD, ENEMY;
+
+	public String toString() {
+		
+		String s = "";
+		switch (this) {
+		case ENEMY:
+			s = "spotted enemies";
+			break;
+		case GOLD:
+			s = "found gold";
+			break;
+		case HUNT:
+			s = "hunted a rabbit";
+			break;
+		case TALE:
+			s = "tells a tale";
+			break;
+		default:
+			break;
+		}
+		return s;
+	};
+}

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

@@ -0,0 +1,23 @@
+package com.iluwatar;
+
+public class App 
+{
+    public static void main( String[] args )
+    {
+    	Party party = new PartyImpl();
+    	Hobbit hobbit = new Hobbit();
+    	Wizard wizard = new Wizard();
+    	Rogue rogue = new Rogue();
+    	Hunter hunter = new Hunter();
+    	
+    	party.addMember(hobbit);
+    	party.addMember(wizard);
+    	party.addMember(rogue);
+    	party.addMember(hunter);
+    	
+    	hobbit.act(Action.ENEMY);
+    	wizard.act(Action.TALE);
+    	rogue.act(Action.GOLD);
+    	hunter.act(Action.HUNT);
+    }
+}

mediator/src/main/java/com/iluwatar/Hobbit.java

@@ -0,0 +1,10 @@
+package com.iluwatar;
+
+public class Hobbit extends PartyMemberBase {
+
+	@Override
+	public String toString() {
+		return "Hobbit";
+	}
+
+}

mediator/src/main/java/com/iluwatar/Hunter.java

@@ -0,0 +1,10 @@
+package com.iluwatar;
+
+public class Hunter extends PartyMemberBase {
+
+	@Override
+	public String toString() {
+		return "Hunter";
+	}
+
+}

mediator/src/main/java/com/iluwatar/Party.java

@@ -0,0 +1,9 @@
+package com.iluwatar;
+
+public interface Party {
+
+	void addMember(PartyMember member);
+	
+	void act(PartyMember actor, Action action);
+	
+}

mediator/src/main/java/com/iluwatar/PartyImpl.java

@@ -0,0 +1,37 @@
+package com.iluwatar;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PartyImpl implements Party {
+
+	private List<PartyMember> members;
+	
+	public PartyImpl() {
+		members = new ArrayList<>();
+	}
+	
+	@Override
+	public void act(PartyMember actor, Action action) {
+		for (PartyMember member: members) {
+			if (member != actor) {
+				member.partyAction(action);
+			}
+		}
+	}
+
+	@Override
+	public void addMember(PartyMember member) {
+		members.add(member);
+		member.joinedParty(this);
+	}
+	
+	// somebody hunts for food, call for dinner
+	
+	// somebody spots enemy, alert everybody
+	
+	// somebody finds gold, deal the gold with everybody
+	
+	// somebody tells a tale, call everybody to listen
+	
+}

mediator/src/main/java/com/iluwatar/PartyMember.java

@@ -0,0 +1,10 @@
+package com.iluwatar;
+
+public interface PartyMember {
+
+	void joinedParty(Party party);
+	
+	void partyAction(Action action);
+
+	void act(Action action);
+}

mediator/src/main/java/com/iluwatar/PartyMemberBase.java

@@ -0,0 +1,46 @@
+package com.iluwatar;
+
+public abstract class PartyMemberBase implements PartyMember {
+
+	protected Party party;
+
+	@Override
+	public void joinedParty(Party party) {
+		System.out.println(this + " joins the party");
+		this.party = party;
+	}
+
+	@Override
+	public void partyAction(Action action) {
+		String s = this + " ";
+		switch (action) {
+		case ENEMY:
+			s = s + "runs for cover";
+			break;
+		case GOLD:
+			s = s + "takes his share of the gold";
+			break;
+		case HUNT:
+			s = s + "arrives for dinner";
+			break;
+		case TALE:
+			s = s + "comes to listen";
+			break;
+		default:
+			break;
+		}
+		System.out.println(s);
+	}
+	
+	@Override
+	public void act(Action action) {
+		if (party != null) {
+			System.out.println(this + " " + action.toString());
+			party.act(this, action);
+		}
+	}
+
+	@Override
+	public abstract String toString();
+	
+}

mediator/src/main/java/com/iluwatar/Rogue.java

@@ -0,0 +1,10 @@
+package com.iluwatar;
+
+public class Rogue extends PartyMemberBase {
+
+	@Override
+	public String toString() {
+		return "Rogue";
+	}
+
+}

mediator/src/main/java/com/iluwatar/Wizard.java

@@ -0,0 +1,10 @@
+package com.iluwatar;
+
+public class Wizard extends PartyMemberBase {
+
+	@Override
+	public String toString() {
+		return "Wizard";
+	}
+
+}

pom.xml

@@ -34,6 +34,7 @@
     <module>command</module>
     <module>interpreter</module>
     <module>iterator</module>
+    <module>mediator</module>
   </modules>
   
 <build>