使用jedis实现Redis消息队列(MQ)的发布(publish)和消息监听(subscribe)

前言：

本文基于jedis 2.9.0.jar、commons-pool2-2.4.2.jar以及json-20160810.jar

其中jedis连接池需要依赖commons-pool2包，json包用于对象实例和json字符串的相互转换

1、jedis的消息队列方法简述

1.1、发布消息方法

（其中，channel是对应消息通道，message是对应消息体）

jedis.publish(channel, message);

1.2、监听消息方法

（其中，jedisPubSub用于处理监听到的消息，channels是对应的通道）

jedis.subscribe(jedisPubSub, channels);

2、发布消息

/**
	 * 从jedis连接池获取jedis操作实例
	 * @return
	 */
	public static Jedis getJedis() {
		return RedisPoolManager.getJedis();
	}

	/**
	 * 推入消息到redis消息通道
	 *
	 * @param String
	 *            channel
	 * @param String
	 *            message
	 */
	public static void publish(String channel, String message) {
		Jedis jedis = null;
		try {
			jedis = getJedis();
			jedis.publish(channel, message);
		} finally {
			jedis.close();
		}
	}

	/**
	 * 推入消息到redis消息通道
	 *
	 * @param byte[]
	 *            channel
	 * @param byte[]
	 *            message
	 */
	public void publish(byte[] channel, byte[] message) {
		Jedis jedis = null;
		try {
			jedis = getJedis();
			jedis.publish(channel, message);
		} finally {
			jedis.close();
		}

	}

3、监听消息

3.1、监听消息主体方法

/**
	 * 监听消息通道
	 * @param jedisPubSub - 监听任务
	 * @param channels - 要监听的消息通道
	 */
	public static void subscribe(BinaryJedisPubSub jedisPubSub, byte[]... channels) {
		Jedis jedis = null;
		try {
			jedis = getJedis();
			jedis.subscribe(jedisPubSub, channels);
		} finally {
			jedis.close();
		}
	}

	/**
	 * 监听消息通道
	 * @param jedisPubSub - 监听任务
	 * @param channels - 要监听的消息通道
	 */
	public static void subscribe(JedisPubSub jedisPubSub, String... channels) {
		Jedis jedis = null;
		try {
			jedis = getJedis();
			jedis.subscribe(jedisPubSub, channels);
		} finally {
			jedis.close();
		}
	}

3.2、处理监听到的消息任务

class Tasker implements Runnable {
	private String[] channel = null;//监听的消息通道
	private JedisPubSub jedisPubSub = null;//消息处理任务

	public Tasker(JedisPubSub jedisPubSub, String ...channel) {
		this.jedisPubSub = jedisPubSub;
		this.channel = channel;
	}

	@Override
	public void run() {
		// 监听channel通道的消息
		RedisMQ.subscribe(jedisPubSub, channel);
	}

}

3.3、处理监听到的消息主体类实现

package cn.eguid.livePushServer.redisManager;

import java.util.Map;

import org.json.JSONObject;

import cc.eguid.livepush.PushManager;
import redis.clients.jedis.JedisPubSub;

public class RedisMQHandler extends JedisPubSub{
	PushManager pushManager = null;

	public RedisMQHandler(PushManager pushManager) {
		super();
		this.pushManager = pushManager;
	}

	@Override
	// 接收到消息后进行分发执行
	public void onMessage(String channel, String message) {
		JSONObject jsonObj = new JSONObject(message);
		System.out.println(channel+","+message);
		if ("push".equals(channel)) {
			Map<String,Object> map=jsonObj.toMap();
			System.out.println("接收到一条推流消息，准备推流："+map);
//			String appName=pushManager.push(map);
			//推流完成后还需要发布一个成功消息到返回队列

		} else if ("close".equals(channel)) {
			String appName=jsonObj.getString("appName");
			System.out.println("接收到一条关闭消息，准备关闭应用："+appName);
//			pushManager.closePush(appName);
		}
	}
}

4、测试消息队列发布和监听

public static void main(String[] args) throws InterruptedException {

		PushManager pushManager= new PushManagerImpl();
		Thread t1 = new Thread(new Tasker(new RedisMQHandler (pushManager), "push"));
		Thread t2 = new Thread(new Tasker(new RedisMQHandler (pushManager), "close"));
		t1.start();
		t2.start();

		LivePushEntity livePushInfo=new LivePushEntity();
		livePushInfo.setAppName("test1");
		JSONObject json=new JSONObject(livePushInfo);
		publish("push",json.toString());
		publish("close", json.toString());
		Thread.sleep(2000);
		publish("push", json.toString());
		publish("close",json.toString());
		Thread.sleep(2000);
		publish("push", json.toString());
		publish("close",json.toString());

	}