发布订阅 · JAVA

[TOC] # 消息监听器类 ~~~ import redis.clients.jedis.JedisPubSub; public class RedisMsgPubSubListener extends JedisPubSub { @Override public void unsubscribe() { super.unsubscribe(); } @Override public void unsubscribe(String... channels) { super.unsubscribe(channels); } @Override public void subscribe(String... channels) { super.subscribe(channels); } @Override public void psubscribe(String... patterns) { super.psubscribe(patterns); } @Override public void punsubscribe() { super.punsubscribe(); } @Override public void punsubscribe(String... patterns) { super.punsubscribe(patterns); } @Override public void onMessage(String channel, String message) { System.out.println("---onMessage---"); System.out.println("channel:" + channel + "receives message :" + message); System.out.println("---onMessage---"); //取消订阅的话就这样,但是后续也就不再监听了 // this.unsubscribe(); } @Override public void onPMessage(String pattern, String channel, String message) { } @Override public void onSubscribe(String channel, int subscribedChannels) { System.out.println("---onSubscribe---"); System.out.println("channel:" + channel + "is been subscribed:" + subscribedChannels); System.out.println("---onSubscribe---"); } @Override public void onPUnsubscribe(String pattern, int subscribedChannels) { } @Override public void onPSubscribe(String pattern, int subscribedChannels) { } @Override public void onUnsubscribe(String channel, int subscribedChannels) { System.out.println("---onUnsubscribe---"); System.out.println("channel:" + channel + "is been unsubscribed:" + subscribedChannels); System.out.println("---onUnsubscribe---"); } } ~~~ 该类需要继承JedisPubSub ，并实现其抽象方法，通过方法的名称很清楚的看出来，这个监听器是用来订阅一个频道，在订阅该频道，可以选择取消订阅，收到消息后也可以再调用其他方法 # 订阅测试类 ~~~ @Test public void testSubscribe() throws Exception { //创建一个jedis客户端对象(redis的客户端连接) Jedis jedis = new Jedis("127.0.0.1", 6379); //设置auth密码 jedis.auth("root"); RedisMsgPubSubListener listener = new RedisMsgPubSubListener(); jedis.subscribe(listener, "redisChatTest"); //other code } ~~~ 该类实现对频道redisChatTest的订阅监听，频道的订阅，取消订阅，收到消息都会调用listener对象的对应方法注意：subscribe是一个阻塞的方法，在取消订阅该频道前，会一直阻塞在这. 只有当取消了订阅才会执行下面的other code，参考上面代码，我在onMessage里面收到消息后，如果调用了this.unsubscribe(); 来取消订阅，这样才会执行后面的other code # 发布消息测试类 ~~~ @Test public void testPublish() throws Exception { //创建一个jedis客户端对象(redis的客户端连接) Jedis jedis = new Jedis("127.0.0.1", 6379); //设置auth密码 jedis.auth("root"); jedis.publish("redisChatTest", "我是天才"); Thread.sleep(5000); jedis.publish("redisChatTest", "我牛逼"); Thread.sleep(5000); jedis.publish("redisChatTest", "哈哈"); } ~~~ 这个类向频道redisChatTest发布消息，第二步因为订阅了该频道，所以会收到该消息。