added composite sample

composite/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>composite</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <name>composite</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>

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

@@ -0,0 +1,21 @@
+package com.iluwatar;
+
+public class App 
+{
+    public static void main( String[] args )
+    {
+    	
+    	System.out.println("Message from the orcs: ");
+    	
+    	LetterComposite orcMessage = new Messenger().messageFromOrcs();
+    	orcMessage.print();
+
+    	System.out.println("\n");
+    	
+    	System.out.println("Message from the elves: ");
+    	
+    	LetterComposite elfMessage = new Messenger().messageFromElves();
+    	elfMessage.print();
+    	
+    }
+}

composite/src/main/java/com/iluwatar/Letter.java

@@ -0,0 +1,21 @@
+package com.iluwatar;
+
+public class Letter extends LetterComposite {
+
+	private char c;
+
+	public Letter(char c) {
+		this.c = c;
+	}
+
+	@Override
+	protected void printThisBefore() {
+		System.out.print(c);
+	}
+
+	@Override
+	protected void printThisAfter() {
+		// nop
+	}
+
+}

composite/src/main/java/com/iluwatar/LetterComposite.java

@@ -0,0 +1,29 @@
+package com.iluwatar;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public abstract class LetterComposite {
+
+	private List<LetterComposite> children = new ArrayList<LetterComposite>();
+
+	public void add(LetterComposite letter) {
+		children.add(letter);
+	}
+	
+	public int count() {
+		return children.size();
+	}
+	
+	protected abstract void printThisBefore();
+
+	protected abstract void printThisAfter();
+	
+	public void print() {
+		printThisBefore();
+		for (LetterComposite letter: children) {
+			letter.print();
+		}
+		printThisAfter();
+	}
+}

composite/src/main/java/com/iluwatar/Messenger.java

@@ -0,0 +1,42 @@
+package com.iluwatar;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class Messenger {
+
+	LetterComposite messageFromOrcs() {
+		
+		List<Word> words = new ArrayList<Word>();
+		
+		words.add(new Word(Arrays.asList(new Letter('W'), new Letter('h'), new Letter('e'), new Letter('r'), new Letter('e'))));
+		words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'), new Letter('e'), new Letter('r'), new Letter('e'))));
+		words.add(new Word(Arrays.asList(new Letter('i'), new Letter('s'))));
+		words.add(new Word(Arrays.asList(new Letter('a'))));
+		words.add(new Word(Arrays.asList(new Letter('w'), new Letter('h'), new Letter('i'), new Letter('p'))));
+		words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'), new Letter('e'), new Letter('r'), new Letter('e'))));
+		words.add(new Word(Arrays.asList(new Letter('i'), new Letter('s'))));
+		words.add(new Word(Arrays.asList(new Letter('a'))));
+		words.add(new Word(Arrays.asList(new Letter('w'), new Letter('a'), new Letter('y'))));
+		
+		return new Sentence(words);
+		
+	}
+
+	LetterComposite messageFromElves() {
+		
+		List<Word> words = new ArrayList<Word>();
+		
+		words.add(new Word(Arrays.asList(new Letter('M'), new Letter('u'), new Letter('c'), new Letter('h'))));
+		words.add(new Word(Arrays.asList(new Letter('w'), new Letter('i'), new Letter('n'), new Letter('d'))));
+		words.add(new Word(Arrays.asList(new Letter('p'), new Letter('o'), new Letter('u'), new Letter('r'), new Letter('s'))));
+		words.add(new Word(Arrays.asList(new Letter('f'), new Letter('r'), new Letter('o'), new Letter('m'))));
+		words.add(new Word(Arrays.asList(new Letter('y'), new Letter('o'), new Letter('u'), new Letter('r'))));
+		words.add(new Word(Arrays.asList(new Letter('m'), new Letter('o'), new Letter('u'), new Letter('t'), new Letter('h'))));
+		
+		return new Sentence(words);
+		
+	}
+	
+}

composite/src/main/java/com/iluwatar/Sentence.java

@@ -0,0 +1,24 @@
+package com.iluwatar;
+
+import java.util.List;
+
+public class Sentence extends LetterComposite {
+
+	public Sentence(List<Word> words) {
+		for (Word w: words) {
+			this.add(w);
+		}
+	}
+	
+	@Override
+	protected void printThisBefore() {
+		// nop
+	}
+
+	@Override
+	protected void printThisAfter() {
+		System.out.print(".");
+	}
+
+
+}

composite/src/main/java/com/iluwatar/Word.java

@@ -0,0 +1,23 @@
+package com.iluwatar;
+
+import java.util.List;
+
+public class Word extends LetterComposite {
+
+	public Word(List<Letter> letters) {
+		for (Letter l: letters) {
+			this.add(l);
+		}
+	}
+	
+	@Override
+	protected void printThisBefore() {
+		System.out.print(" ");
+	}
+
+	@Override
+	protected void printThisAfter() {
+		// nop
+	}
+
+}

pom.xml

@@ -25,5 +25,6 @@
     <module>singleton</module>
     <module>adapter</module>
     <module>bridge</module>
+    <module>composite</module>
   </modules>
 </project>