一、work消息模型-工作队列模型
1.工作队列的含义
主要思想就是避免执行资源密集型任务时,必须等待它执行完成。相反我们稍后完成任务,我们将任务封装为消息并将其发送到队列。 在后台运行的工作进程将获取任务并最终执行作业。当你运行许多消费者时,任务将在他们之间共享,但是一个消息只能被一个消费者获取。两个消费者消费数量相同。
2.弊端问题
- 消费者1比消费者2的效率要低,一次任务的耗时较长
- 然而两人最终消费的消息数量是一样的
- 消费者2大量时间处于空闲状态,消费者1一直忙碌3.解决弊端 让能者多劳channel.basicQos(5);设置客户端最多接收未被ack的消息的个数4.代码展示 1.生产者
publicclassSend{privatestaticfinalStringQUEUE_NAME="work_queue";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException,InterruptedException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);for(int i=0;i<50;i++){String message ="task...."+i;
channel.basicPublish("",QUEUE_NAME,null,message.getBytes());System.out.println("send : "+message);Thread.sleep(i *2);}
channel.close();
con.close();}}
2.消费者1
publicclassRecv1{privatestaticfinalStringQUEUE_NAME="work_queue";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);
channel.basicQos(5);DefaultConsumer consumer =newDefaultConsumer(channel){@OverridepublicvoidhandleDelivery(String consumerTag,Envelope envelope,AMQP.BasicProperties properties,byte[] body)throwsIOException{String msg =newString(body);System.out.println("消费者1 received: "+msg);try{//模拟消费耗时Thread.sleep(1000);}catch(InterruptedException e){
e.printStackTrace();}
channel.basicAck(envelope.getDeliveryTag(),false);}};
channel.basicConsume(QUEUE_NAME,false,consumer);}}
3.消费者2
publicclassRecv2{privatestaticfinalStringQUEUE_NAME="work_queue";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);DefaultConsumer consumer =newDefaultConsumer(channel){@OverridepublicvoidhandleDelivery(String consumerTag,Envelope envelope,AMQP.BasicProperties properties,byte[] body)throwsIOException{String msg =newString(body);System.out.println("消费者2 received: "+msg);
channel.basicAck(envelope.getDeliveryTag(),false);}};
channel.basicConsume(QUEUE_NAME,false,consumer);}}
二、订阅模型分类
1.订阅模型的含义
在这一部分,我们将做一些完全不同的事情 - 我们将会传递一个信息给多个消费者
特点:
1、1个生产者,多个消费者
2、每一个消费者都有自己的一个队列
3、生产者没有将消息直接发送到队列,而是发送到了交换机
4、每个队列都要绑定到交换机
5、生产者发送的消息,经过交换机到达队列,实现一个消息被多个消费者获取的目的
2.交换机的作用和类型
交换机一方面:接收生产者发送的消息。另一方面:知道如何处理消息,例如递交给某个特别队列、递交给所有队列、或是将消息丢弃。到底如何操作,取决于Exchange的类型。
- Fanout:广播,将消息交给所有绑定到交换机的队列
- Direct:定向,把消息交给符合指定routing key 的队列
- Topic:通配符,把消息交给符合routing pattern(路由模式) 的队列
三、订阅模型-Fanout
1.广播模式的流程
- 1) 可以有多个消费者
- 2) 每个消费者有自己的queue(队列)
- 3) 每个队列都要绑定到Exchange(交换机)
- 4) 生产者发送的消息,只能发送到交换机,交换机来决定要发给哪个队列,生产者无法决定。
- 5) 交换机把消息发送给绑定过的所有队列
- 6) 队列的消费者都能拿到消息。实现一条消息被多个消费者消费2.代码展示 1.生产者
publicclassSend{privatefinalstaticStringEXCHANGE_NAME="fanout_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();// 声明exchange,指定类型为fanout
channel.exchangeDeclare(EXCHANGE_NAME,"fanout");String message ="hello everyone";// 发布消息到Exchange
channel.basicPublish(EXCHANGE_NAME,"",null,message.getBytes());System.out.println(" Sent : "+ message +"'");
channel.close();
con.close();}}
2.消费者1
publicclassRecv1{privatefinalstaticStringQUEUE_NAME="fanout_queue_1";privatefinalstaticStringEXCHANGE_NAME="fanout_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);// 绑定队列到交换机
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"");DefaultConsumer consumer =newDefaultConsumer(channel){@OverridepublicvoidhandleDelivery(String consumerTag,Envelope envelope,AMQP.BasicProperties properties,byte[] body)throwsIOException{String msg =newString(body);System.out.println("消费者1 :"+msg);}};// 监听队列,自动返回完成
channel.basicConsume(QUEUE_NAME,true,consumer);}}
2.消费者2
publicclassRecv2{privatefinalstaticStringQUEUE_NAME="fanout_queue_2";privatefinalstaticStringEXCHANGE_NAME="fanout_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"");DefaultConsumer consumer =newDefaultConsumer(channel){@OverridepublicvoidhandleDelivery(String consumerTag,Envelope envelope,AMQP.BasicProperties properties,byte[] body)throwsIOException{String msg =newString(body);System.out.println("消费者2 :"+msg);}};
channel.basicConsume(QUEUE_NAME,true,consumer);}}
四、订阅模型-Direct
1.定向订阅模型含义
在某些场景下,我们希望不同的消息被不同的队列消费。这时就要用到Direct类型的Exchange。
在Direct模型下,队列与交换机的绑定,不能是任意绑定了,而是要指定一个RoutingKey(路由key)
消息的发送方在向Exchange发送消息时,也必须指定消息的routing key。
- 生产者,向Exchange发送消息,发送消息时,会指定一个routing key。 -Exchange(交换机),接收生产者的消息,然后把消息递交给 与routing key完全匹配的队列
- 消费者,其所在队列指定了需要routing key 为 error 的消息
- 消费者,其所在队列指定了需要routing key 为 info、error、warning 的消息2.代码展示 1.生产者
publicclassSend{privatefinalstaticStringEXCHANGE_NAME="direct_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.exchangeDeclare(EXCHANGE_NAME,"direct");String message ="插入商品";
channel.basicPublish(EXCHANGE_NAME,"insert",null,message.getBytes());System.out.println("send : "+message);
channel.close();
con.close();}}
2.消费者1
publicclassRecv1{privatefinalstaticStringQUEUE_NAME="direct_queue_1";privatefinalstaticStringEXCHANGE_NAME="direct_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"update");
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"delete");DefaultConsumer consumer =newDefaultConsumer(channel){@OverridepublicvoidhandleDelivery(String consumerTag,Envelope envelope,AMQP.BasicProperties properties,byte[] body)throwsIOException{String msg =newString(body);System.out.println("消费者1接收: "+msg);}};
channel.basicConsume(QUEUE_NAME,true,consumer);}}
2.消费者2
publicclassRecv2{privatefinalstaticStringQUEUE_NAME="direct_queue_2";privatefinalstaticStringEXCHANGE_NAME="direct_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"insert");
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"update");
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"delete");DefaultConsumer consumer =newDefaultConsumer(channel){@OverridepublicvoidhandleDelivery(String consumerTag,Envelope envelope,AMQP.BasicProperties properties,byte[] body)throwsIOException{String msg =newString(body);System.out.println("消费者2接收: "+msg);}};
channel.basicConsume(QUEUE_NAME,true,consumer);}}
五、订阅模型-Topic
1.通配符订阅含义
Topic类型的Exchange与Direct相比,都是可以根据RoutingKey把消息路由到不同的队列。只不过Topic类型Exchange可以让队列在绑定Routing key 的时候使用通配符!
2…通配符规则
- #:匹配一个或多个词
- *:匹配不多不少恰好1个词
- audit.#:能够匹配audit.irs.corporate 或者 audit.irs
- audit.*:只能匹配audit.irs
3.代码展示
1.生产者
publicclassSend{privatefinalstaticStringEXCHANGE_NAME="topic_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.exchangeDeclare(EXCHANGE_NAME,"topic");String message ="商品新增";
channel.basicPublish(EXCHANGE_NAME,"item.insert",null,message.getBytes());System.out.println("send : "+message);
channel.close();
con.close();}}
2.消费者1
publicclassRecv1{privatefinalstaticStringQUEUE_NAME="topic_queue_1";privatefinalstaticStringEXCHANGE_NAME="topic_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"item.insert");
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"item.delete");DefaultConsumer consumer =newDefaultConsumer(channel){@OverridepublicvoidhandleDelivery(String consumerTag,Envelope envelope,AMQP.BasicProperties properties,byte[] body)throwsIOException{String msg =newString(body);System.out.println("消费者1接收: "+msg);}};
channel.basicConsume(QUEUE_NAME,true,consumer);}}
3.消费者2
publicclassRecv2{privatefinalstaticStringQUEUE_NAME="topic_queue_2";privatefinalstaticStringEXCHANGE_NAME="topic_exchange";publicstaticvoidmain(String[] args)throwsIOException,TimeoutException{Connection con =ConnectionUtil.getCon();Channel channel = con.createChannel();
channel.queueDeclare(QUEUE_NAME,false,false,false,null);
channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"item.*");DefaultConsumer consumer =newDefaultConsumer(channel){@OverridepublicvoidhandleDelivery(String consumerTag,Envelope envelope,AMQP.BasicProperties properties,byte[] body)throwsIOException{String msg =newString(body);System.out.println("消费者2接收: "+msg);}};
channel.basicConsume(QUEUE_NAME,true,consumer);}}
六、持久化
1.持久化含义
- 消费者的ACK机制。可以防止消费者丢失消息。
- 但是,如果在消费者消费之前,MQ就宕机了,消息就没了。
- 要将消息持久化,前提是:队列、Exchange都持久化
2.代码展示
1.交换机持久化
channel.exchangeDeclare(EXCHANGE_NAME,"topic",true);
2.队列持久化
channel.queueDeclare(QUEUE_NAME,true,false,false,null);
3.消息持久化
channel.basicPublish(EXCHANGE_NAME,"item.insert",MessageProperties.PERSISTENT_TEXT_PLAIN,message.getBytes());
上面是五种消息模型,以及持久化,rabbitmq到此结束不足之处,望海涵
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