一、什么是中介者模式
对象之间通过中介者对象进行交互，而不是直接交互；
二、补充说明
对紧密关联的各个对象解耦；
典型例子：QQ群，聊天室；
三、角色
抽象中介者
具体中介者
抽象对象
具体对象
四、例子，JAVA实现
例子说明，一个网络聊天室
抽象中介者
package com.pichen.dp.behavioralpattern.mediator; import java.util.ArrayList; import java.util.List; public abstract class Mediator { protected List<User> userList; public Mediator() { userList = new ArrayList<User>(); } public void addUser(User user){ user.setMediator(this); this.userList.add(user); } public abstract void operation(User user, String msg); }
具体中介者
package com.pichen.dp.behavioralpattern.mediator; public class ChatRoomMediator extends Mediator { @Override public void operation(User user, String msg) { System.out.println(user.getName() + "send a msg : " + msg); for(User userTmp : this.userList){ userTmp.getMessage(msg); } } }
抽象对象
package com.pichen.dp.behavioralpattern.mediator; public abstract class User { protected Mediator mediator; protected String name; public User(String name) { this.name = name; } protected void setMediator(Mediator mediator){ this.mediator = mediator; } protected abstract void sendMessage(String msg); protected abstract void getMessage(String msg); public String getName() { return name; } public void setName(String name) { this.name = name; } }
具体对象
package com.pichen.dp.behavioralpattern.mediator; public class CommonUser extends User{ public CommonUser(String name) { super(name); } @Override protected void sendMessage(String msg) { this.mediator.operation(this, msg); } @Override protected void getMessage(String msg) { System.out.println(this.getName() + " get msg:"+msg); } }
package com.pichen.dp.behavioralpattern.mediator; public class VIPUser extends User{ public VIPUser(String name) { super(name); } @Override protected void sendMessage(String msg) { this.mediator.operation(this, msg); } @Override protected void getMessage(String msg) { System.out.println(this.getName() + " get msg:"+msg); } }
客户端
package com.pichen.dp.behavioralpattern.mediator; public class Main { public static void main(String[] args) { CommonUser user1 = new CommonUser("小王"); CommonUser user2 = new CommonUser("小陈"); VIPUser vipUser = new VIPUser("小张"); Mediator chatRoom = new ChatRoomMediator(); chatRoom.addUser(user1); chatRoom.addUser(user2); chatRoom.addUser(vipUser); user2.sendMessage("hello everybody~"); } }
执行结果
小陈send a msg : hello everybody~ 小王 get msg:hello everybody~ 小陈 get msg:hello everybody~ 小张 get msg:hello everybody~
本文转自风一样的码农博客园博客，原文链接：http://www.cnblogs.com/chenpi/p/5222152.html，如需转载请自行联系原作者
