设计模式——行为模式

//客户端接口

public interface UpdatableClient {
     public void update(String msg);
}

//服务端接口

public interface Serverable {
     public void registObserver(Client client);
     public void removeObserver(Client client);
     public void notifyObserver(String msg);
}

//客户实现类

public class Client implements UpdatableClient{
     private String name;
     public Client(String name) {
         // TODO Auto-generated constructor stub
         this.name = name;
     }
    
    
     public String getName() {
         return name;
     }

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

     @Override
     public void update(String msg) {
         // TODO Auto-generated method stub
         System.out.println("client_"+name+"接收到信息："+msg);
     }

}

//服务器实现类

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

public class Server implements Serverable{
     private String name;
     private List<Client> regisTable;
     public Server() {
         regisTable = new ArrayList<Client>();
         name = "默认服务器-administrator";
     }
     public Server(String name, List<Client> regisTable) {
         super();
         this.name = name;
         this.regisTable = regisTable;
     }
     @Override
     public void registObserver(Client client) {
         // TODO Auto-generated method stub
         regisTable.add(client);
     }
     @Override
     public void removeObserver(Client client) {
         // TODO Auto-generated method stub
         regisTable.remove(client);
     }
     @Override
     public void notifyObserver(String msg) {
         // TODO Auto-generated method stub
         for (Client client : regisTable) {
             client.update(msg);
         }
     }
    
}

//测试

public class Demo {
     public static void main(String[] args) {
         Server server = new Server();
         Client clientA = new Client("java");
         server.registObserver(clientA);
         Client clientB = new Client("SQL");
         server.registObserver(clientB);
         Client clientC = new Client("C++");
         server.registObserver(clientC);
         server.notifyObserver("hello,everyone");
        
         server.removeObserver(clientB);
         server.notifyObserver("hello,remove client_"+clientB.getName());
        
     }
}