//Component

import java.util.*;

abstract class Employer {

private String name;

public void setName(String name) {

this.name = name;

}

public String getName() {

return this.name;

}

public abstract void add(Employer employer);

public abstract void delete(Employer employer);

public List employers;

public void printInfo() {

System.out.println(name);

}

public List getEmployers() {

return this.employers;

}

}

//Leaf

class Programmer extends Employer {

public Programmer(String name) {

setName(name);

employers = null;//程序员, 表示没有下属了

}

public void add(Employer employer) {

}

public void delete(Employer employer) {

}

}

class ProcectAssistant extends Employer {

public ProcectAssistant(String name) {

setName(name);

employers = null;//项目助理, 表示没有下属了

}

public void add(Employer employer) {

}

public void delete(Employer employer) {

}

}

//Composite

class ProjectManager extends Employer {

public ProjectManager(String name) {

setName(name);

employers = new ArrayList();

}

public void add(Employer employer) {

employers.add(employer);

}

public void delete(Employer employer) {

employers.remove(employer);

}

}

//Client

public class DS08_Composite {

public static void main(String[] args) {

Employer pm = new ProjectManager("项目经理");

Employer pa = new ProcectAssistant("项目助理");

Employer programmer1 = new Programmer("程序员一");

Employer programmer2 = new Programmer("程序员二");

pm.add(pa);//为项目经理添加项目助理

pm.add(programmer2);//为项目经理添加程序员

//注意，这里如果不加<>里面的东西，竟然不能编译通过，这个是因为泛型编程

List<Employer> ems = pm.getEmployers();

int emsCount = ems.size();

for(int i = 0; i <emsCount;++i)

{

Employer em = ems.get(i);

System.out.println(em.getName());

}

/*

for (Employer em : ems) {

System.out.println(em.getName());

}

*/

}

}