Flexible structure Composite : Composite Pattern « Design Pattern « Java Tutorial

1. Java Tutorial
2. Design Pattern
3. Composite Pattern

import java.util.ArrayList;
import java.util.Iterator;

interface Movable {
  void operation();
}

class File implements Movable {
  private String name;

  public File(String name) {
    this.name = name;
  }

  public String toString() {
    return name;
  }

  public void operation() {
    System.out.println(this);
  }
}

class FileTree extends ArrayList<Movable> implements Movable {
  private String name;

  public FileTree(String name) {
    this.name = name;
  }

  public String toString() {
    return name;
  }

  public void operation() {
    System.out.println(this);
    for (Iterator<Movable> it = iterator(); it.hasNext();)
      it.next().operation();
  }
}

public class CompositeStructure {
  public static void main(String args[]) {
    FileTree root = new FileTree("root");
    root.add(new File("Leaf1"));
    FileTree c2 = new FileTree("Node1");
    c2.add(new File("Leaf2"));
    c2.add(new File("Leaf3"));
    root.add(c2);
    c2 = new FileTree("Node2");
    c2.add(new File("Leaf4"));
    c2.add(new File("Leaf5"));
    root.add(c2);
    root.operation();
  }
}