Redis的事务和消息机制

Java操作事务

@Test
	public void testTransaction(){
		Jedis jedis = new Jedis("192.168.131.111", 6379);
		
		//开启事务
		Transaction tc = null;
		
		try {
			tc = jedis.multi();
			tc.decrBy("tom",100);
			tc.incrBy("mike", 100);
			//提交事务
			tc.exec();
		} catch (Exception e) {
			e.printStackTrace();
			//回滚事务
			tc.discard();
		}
		jedis.disconnect();
	}

Java操作锁

@Test
	public void testLock(){
		
		Jedis jedis = new Jedis("192.168.131.111", 6379);
		//对ticket加锁，入伙在事务执行的过程中，该值有变化，则抛出异常
		jedis.watch("ticket");
		
		Transaction tc = null;
		try {
			tc = jedis.multi();
			tc.decr("ticket"); //车票刷量减1
			
			//如果在线程睡眠的过程中 ticket监控的值有变化，则抛出异常
			Thread.sleep(10000);
			tc.decrBy("tom", 100);//扣取买票钱
			
			//提交事务
			tc.exec();
			
		} catch (Exception e) {
			e.printStackTrace();
			tc.discard();
		}
		
	}

Demo

• 使用Java程序实现消息的发布与订阅，需要继承JedisPubSub 类

  @Test
  public void testMessage(){
  	Jedis jedis = new Jedis("192.168.131.111", 6379);
  	
  	//subscribe 和 psubcribe 不能同时订阅
  	jedis.subscribe(new MyRedisMessageConsumer(), "channel");
  	//jedis.pshbscribe(new MyRedisMessageConsumer(),"channel");
  	
  }

  //实现Redis消息的接受者
  class MyRedisMessageConsumer extends JedisPubSub{
  
  	@Override
  	public void onMessage(String channel, String message) {
  		// 订阅某个频道的
  		System.out.println(channel+ "\t" + message);
  	}
  
  	@Override
  	public void onPMessage(String pattern, String channel, String message) {
  		// 用通配符匹配频道
  		System.out.println("pattern:"+pattern);
  		System.out.println("channel:"+channel);
  		System.out.println("message:"+message);
  	}
  	@Override
  	public void onPSubscribe(String arg0, int arg1) {}
  	@Override
  	public void onPUnsubscribe(String arg0, int arg1) {}
  	@Override
  	public void onSubscribe(String arg0, int arg1) {}
  	@Override
  	public void onUnsubscribe(String arg0, int arg1) {}
  	
  }