Composite

Composite Pattern:意图是将对象组合成树形结构以表示部分-整体的层次结构，它使得用户对单个对象和组合对象的使用具有一致性。

下面以Iterator中的例子为例，不过，这里Department中除了含有Clerk外，也可以再含有子Department，它含有的子Department中也可以含有Clerk和Department，代码如下：

DepartComponent.java

package com.flyingh.abs;

public abstract class DepartComponent {
	public void add(DepartComponent departComponent) {
		throw new UnsupportedOperationException();
	}

	public void remove(DepartComponent departComponent) {
		throw new UnsupportedOperationException();
	}

	public DepartComponent getChild(int i) {
		throw new UnsupportedOperationException();
	}

	public abstract void print();
}

 Clerk.java

package com.flyingh.bean;

import com.flyingh.abs.DepartComponent;
import com.flyingh.util.Sex;

public class Clerk extends DepartComponent {
	private String id;
	private String name;
	private int age;
	private Sex sex;
	private float salary;

	public Clerk(String id, String name, int age, Sex sex, float salary) {
		super();
		this.id = id;
		this.name = name;
		this.age = age;
		this.sex = sex;
		this.salary = salary;
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public Sex getSex() {
		return sex;
	}

	public void setSex(Sex sex) {
		this.sex = sex;
	}

	public float getSalary() {
		return salary;
	}

	public void setSalary(float salary) {
		this.salary = salary;
	}

	@Override
	public String toString() {
		return "Clerk [id=" + id + ", name=" + name + ", age=" + age + ", sex="
				+ sex + ", salary=" + salary + "]";
	}

	@Override
	public void print() {
		// TODO Auto-generated method stub
		System.out.println(this);
	}
}

Sex.java

package com.flyingh.util;

public enum Sex {
	man, woman;
} 

Depart.java

package com.flyingh.bean;

import java.util.ArrayList;
import java.util.List;

import com.flyingh.abs.DepartComponent;

public class Depart extends DepartComponent {
	private List<DepartComponent> list = new ArrayList<DepartComponent>();

	public Depart(List<DepartComponent> list) {
		super();
		this.list = list;
	}

	@Override
	public void add(DepartComponent departComponent) {
		// TODO Auto-generated method stub
		list.add(departComponent);
	}

	@Override
	public void remove(DepartComponent departComponent) {
		// TODO Auto-generated method stub
		list.remove(departComponent);
	}

	@Override
	public DepartComponent getChild(int i) {
		// TODO Auto-generated method stub
		return list.get(i);
	}

	@Override
	public void print() {
		// TODO Auto-generated method stub
		for (DepartComponent departComponent : list) {
			departComponent.print();
		}
	}

}

 Boss.java

package com.flyingh.bean;

import java.util.ArrayList;
import java.util.List;

import com.flyingh.abs.DepartComponent;

public class Boss {
	private List<DepartComponent> allList = new ArrayList<DepartComponent>();

	public Boss(List<DepartComponent> allList) {
		super();
		this.allList = allList;
	}

	public void printAllClerk() {
		for (DepartComponent departComponent : allList) {
			departComponent.print();
		}
	}
}

 Client.java

package com.flyingh.client;

import java.util.ArrayList;
import java.util.List;

import com.flyingh.abs.DepartComponent;
import com.flyingh.bean.Boss;
import com.flyingh.bean.Clerk;
import com.flyingh.bean.Depart;
import com.flyingh.util.Sex;

public class Client {
	public static void main(String[] args) {
		DepartComponent clerk1 = new Clerk("001", "zhangsan", 22, Sex.man, 8000);
		DepartComponent clerk2 = new Clerk("002", "lisi", 23, Sex.woman, 7788);

		DepartComponent clerkA1 = new Clerk("A1", "wangwuA", 25, Sex.man, 8800);
		DepartComponent clerkA2 = new Clerk("A2", "hahaA", 22, Sex.woman, 7878);
		List<DepartComponent> listA = new ArrayList<DepartComponent>();
		listA.add(clerkA1);
		listA.add(clerkA2);
		DepartComponent departA = new Depart(listA);

		DepartComponent clerkB1 = new Clerk("B1", "wangwuB", 25, Sex.man, 8800);
		DepartComponent clerkB2 = new Clerk("B2", "hahaB", 22, Sex.woman, 7878);
		List<DepartComponent> subList = new ArrayList<DepartComponent>();
		subList.add(new Clerk("subB1", "hehe", 21, Sex.man, 7000));
		subList.add(new Clerk("subB2", "heihei", 23, Sex.man, 7788));
		DepartComponent subDepartB = new Depart(subList);
		List<DepartComponent> listB = new ArrayList<DepartComponent>();
		listB.add(clerkB1);
		listB.add(clerkB2);
		listB.add(subDepartB);
		DepartComponent departB = new Depart(listB);

		DepartComponent clerkC1 = new Clerk("C1", "wangwuC", 25, Sex.man, 8800);
		DepartComponent clerkC2 = new Clerk("C2", "hahaC", 22, Sex.woman, 7878);
		DepartComponent clerkC3 = new Clerk("C3", "heheC", 22, Sex.man, 7879);
		List<DepartComponent> listC = new ArrayList<DepartComponent>();
		listC.add(clerkC1);
		listC.add(clerkC2);
		listC.add(clerkC3);
		DepartComponent departC = new Depart(listC);

		List<DepartComponent> allList = new ArrayList<DepartComponent>();
		allList.add(clerk1);
		allList.add(clerk2);
		allList.add(departA);
		allList.add(departB);
		allList.add(departC);
		Boss boss = new Boss(allList);

		boss.printAllClerk();

	}
}

 程序运行结果如下：

Clerk [id=001, name=zhangsan, age=22, sex=man, salary=8000.0]
Clerk [id=002, name=lisi, age=23, sex=woman, salary=7788.0]
Clerk [id=A1, name=wangwuA, age=25, sex=man, salary=8800.0]
Clerk [id=A2, name=hahaA, age=22, sex=woman, salary=7878.0]
Clerk [id=B1, name=wangwuB, age=25, sex=man, salary=8800.0]
Clerk [id=B2, name=hahaB, age=22, sex=woman, salary=7878.0]
Clerk [id=subB1, name=hehe, age=21, sex=man, salary=7000.0]
Clerk [id=subB2, name=heihei, age=23, sex=man, salary=7788.0]
Clerk [id=C1, name=wangwuC, age=25, sex=man, salary=8800.0]
Clerk [id=C2, name=hahaC, age=22, sex=woman, salary=7878.0]
Clerk [id=C3, name=heheC, age=22, sex=man, salary=7879.0]