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【Java设计者模式】-Java实现订阅-发布者模式

主要由发布者和订阅者两种构成。消息生产者向频道发送一个消息之后，多个消费者可以从该频道订阅到这条消息并消费。

订阅者接口

package com.lcz.design_mode;// 订阅者接口public interface ISubsriber {
   	// 订阅者得到这个消息各自的处理	void todoTomorrow(String msg);}

发布者接口

package com.lcz.design_mode;// 发布者接口public interface IWeather {
   	// 添加订阅者	void addSubscriber(ISubsriber subsriber);	// 删除订阅者	void delSubscriber(ISubsriber subsriber);	// 发布消息的接口	void publishInfo(String msg);}

发布者的实现

package com.lcz.design_mode;import java.util.ArrayList;import java.util.List;import com.sun.istack.internal.logging.Logger;// 实现发布者public class WeatherServer implements IWeather {
   	// 日志记录	private static final Logger logger = Logger.getLogger(WeatherServer.class);	// 保存发布者	private List
   
     subsribers = new ArrayList
    
     ();	// 保存所有的订阅者	@Override	public void addSubscriber(ISubsriber subsriber) {
   		// TODO Auto-generated method stub		subsribers.add(subsriber);		logger.info("a new subscriber is joining");	}	// 用来删除发布者	@Override	public void delSubscriber(ISubsriber subsriber) {
   		// TODO Auto-generated method stub		subsribers.remove(subsriber);		logger.info("a subscriber is leaving");	}		// 用来发布消息	@Override	public void publishInfo(String msg) {
   		// TODO Auto-generated method stub		for(ISubsriber subsriber:subsribers) {
   			subsriber.todoTomorrow(msg);		}		logger.info(String.format("public a msg: %s", msg));	}}
    
   

订阅者的实现

package com.lcz.design_mode;import com.sun.istack.internal.logging.Logger;public class Worker implements ISubsriber{
   	// 日志	private static final Logger logger = Logger.getLogger(Worker.class);	@Override	public void todoTomorrow(String msg) {
   		// TODO Auto-generated method stub		if("rain".equals(msg)) {
   			logger.info("worker: a satified day");		}else if("sunny".equals(msg)) {
   			logger.info("worker: a terrible day");		}else {
   			logger.info("worker: spam messages");		}			}}

测试

package com.lcz.design_mode;public class Test {
   	public static void main(String[] args) {
   		// 创建订阅者		Worker worker = new Worker();				WeatherServer weatherServer = new WeatherServer();				weatherServer.addSubscriber(worker);		weatherServer.publishInfo("rain");	}}

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