• RabbitMQ系列(三)--Java API


    基于java使用RabbitMQ

    框架:SpringBoot1.5.14.RELEASE

    maven依赖:

    <dependency>
        <groupId>com.rabbitmq</groupId>
        <artifactId>amqp-client</artifactId>
        <version>3.6.5</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-amqp</artifactId>
    </dependency>

    本文只是操作原生RabbitMQ,并没有和SpringBoot进行整合,后面介绍整合,基于注解使用

    一、quick start

    1.1、Consumer

    public static void main(String[] args) throws Exception{
            //1 创建一个ConnectionFactory, 并进行配置
            ConnectionFactory factory = new ConnectionFactory();
            factory.setVirtualHost("/");
            factory.setHost("139.196.75.238");
            factory.setPort(5672);
            //2 通过连接工厂创建连接
            Connection connection = factory.newConnection();
            //3 通过connection创建一个Channel
            Channel channel = connection.createChannel();
    
            //4 声明(创建)一个队列
            channel.queueDeclare("test002", true, false, false, null);
    
            //5 创建消费者
            QueueingConsumer queueingConsumer = new QueueingConsumer(channel);
    
            //6 设置Channel
            channel.basicConsume("test002", true, queueingConsumer);
    
            while(true){
                //7 获取消息
                QueueingConsumer.Delivery delivery = queueingConsumer.nextDelivery();
                String msg = new String(delivery.getBody());
                log.info(msg);
            }
        }
    }
    Consumer

    参数解释:

      durable:是否持久化,Durable:是,即使服务器重启,这个队列也不会消失,Transient:否

      exclusive:这个queue只能由一个exchange监听restricted to this connection,使用场景:顺序消费

      autoDelete:当最后一个Binding到Exchange的Queue删除之后,自动删除该Exchange

      arguments:参数

      autoACK:是否自动签收,对应着手动签收

    1.2、Producer

    public class Producer {
    
        public static void main(String[] args) throws Exception{
            //1 创建一个ConnectionFactory, 并进行配置
            ConnectionFactory factory = new ConnectionFactory();
            factory.setVirtualHost("/");
            factory.setHost("139.196.75.238");
            factory.setPort(5672);
            //2 通过连接工厂创建连接
            Connection connection = factory.newConnection();
            //3 通过connection创建一个Channel
            Channel channel = connection.createChannel();
            //4 通过Channel发送数据
            for(int i=0; i < 5; i++){
                String msg = "Hello RabbitMQ!";
                //1 exchange   2 routingKey
                channel.basicPublish("", "test002", null, msg.getBytes());
            }
            //5 关闭相关的连接
            channel.close();
            factory.clone();
        }
    }
    Producer

    参数解释:

      exchange name:

      routingKey:路由规则

      BasicProperties:

      body:message中的body

    结果:

    17:43:49.351 [main] INFO com.it.quickstart.Consumer - Hello RabbitMQ!
    17:43:49.351 [main] INFO com.it.quickstart.Consumer - Hello RabbitMQ!
    17:43:49.351 [main] INFO com.it.quickstart.Consumer - Hello RabbitMQ!
    17:43:49.351 [main] INFO com.it.quickstart.Consumer - Hello RabbitMQ!
    17:43:49.351 [main] INFO com.it.quickstart.Consumer - Hello RabbitMQ!

      我们使用RabbitMQ,需要首先在可视化界面确定queue,exchange是否创建,对应关系是否正常,这是一个大前提

    1.3、自定义消费者

      之前接收message,通过while(true),感觉太low了,RabbitMQ支持实现自定义消费者,只需要集成DefaultConsumer,重写handlerDelivery,

    构造器

    public class MyConsumer extends DefaultConsumer {
        public MyConsumer(Channel channel) {
            super(channel);
        }
    
        @Override
        public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
            System.err.println("-----------consume message----------");
            System.err.println("consumerTag: " + consumerTag);
            System.err.println("envelope: " + envelope);
            System.err.println("properties: " + properties);
            System.err.println("body: " + new String(body));
        }
    }
    MyConsumer

    而consumer只需要修改

    //5 创建消费者
    QueueingConsumer queueingConsumer = new QueueingConsumer(channel);            //去掉这一步
    //6 设置Channel channel.basicConsume("test002", true, new MyConsumer(channel));

    结果:

    -----------consume message----------
    consumerTag: amq.ctag-YK7CnvWxTpm6hmuyUyqSkQ
    envelope: Envelope(deliveryTag=1, redeliver=false, exchange=, routingKey=test002)
    properties: #contentHeader<basic>(content-type=null, content-encoding=null, headers=null, delivery-mode=null, priority=null, correlation-id=null, reply-to=null, expiration=null, message-id=null, timestamp=null, type=null, user-id=null, app-id=null, cluster-id=null)
    body: Hello RabbitMQ By MyConsumer!

    二、Exchange

      Exchange有四种方式Fanout、Direct、Topic、Headers,而我们上面的例子,并没有定义Exchange,RabbitMQ默认使用AMQP default,

    要求routing key和queue name相同

      本文只是介绍前三种,Headers几乎用不到

    2.1、Fanout

    fanout效率是最好的,不需要routing key,你可以随便设置都无所谓,只要consumer和producer的Exchange name相同

    producer

    public class Producer {
    
        public static void main(String[] args) throws Exception{
            ConnectionFactory factory = new ConnectionFactory();
            factory.setVirtualHost("/");
            factory.setHost("139.196.75.238");
            factory.setPort(5672);
    
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();
    
            String exchangeName = "exchange_fanout";
            channel.basicPublish(exchangeName, "", null, "send message by fanout".getBytes());
        }
    }
    Producer Fanout

    consumer

    public class Consumer {
    
        public static void main(String[] args) throws Exception{
            ConnectionFactory factory = new ConnectionFactory();
            factory.setVirtualHost("/");
            factory.setHost("139.196.75.238");
            factory.setPort(5672);
    
            factory.setAutomaticRecoveryEnabled(true);
            factory.setNetworkRecoveryInterval(3000);
    
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();
    
            String exchangeName = "exchange_fanout";
            String exchangeType = "fanout";
            String queueName = "queue_fanout";
            String routingKey = "";    //不设置路由键
    
            channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
            channel.queueDeclare(queueName, true, false, false, null);
            channel.queueBind(queueName, exchangeName, routingKey);
    
            channel.basicConsume(queueName, true, new MyConsumer(channel));
        }
    }
    Consumer Fanout

    结果:

    -----------consume message----------
    consumerTag: amq.ctag-rXw7SbaR5aWVMQxZY6SfEA
    envelope: Envelope(deliveryTag=1, redeliver=false, exchange=exchange_fanout, routingKey=)
    properties: #contentHeader<basic>(content-type=null, content-encoding=null, headers=null, delivery-mode=null, priority=null, correlation-id=null, reply-to=null, expiration=null, message-id=null, timestamp=null, type=null, user-id=null, app-id=null, cluster-id=null)
    body: send message by fanout

    我们声明queue和exchange之后,要先观察exchange和queue对应关系

    点击exchange name,进去查看是否binding成功,如果成功如下图

    注意点:

      1、fanout模式下不是直接操作Queue,而是把消息发送给Exchange,由Exchange把消息分发给与之绑定的Queue,也就是广播模式

      2、Queue必须和Exchange进行绑定

      3、每个Consumer的Queue name不能相同,个人测试下,相同的Queue name,只能有一个Consumer收到消息

    2.2、Direct

      完全把代码贴出来太浪费篇幅了,而且毫无意思,后面只说一下区别,顺便说一下,对于queue和exchange的declare无论放到producer还是

    Consumer都可以的,个人习惯Consumer,而且二者启动顺序没有要求,因为RabbitMQ的消息具有堆积功能

    Producer:

     String exchangeName = "exchange_direct";
     String routingKey = "key.direct";
    
     channel.basicPublish(exchangeName, routingKey, null, "send message by direct".getBytes());

    Consumer:

    String exchangeName = "exchange_direct";
    String exchangeType = "direct";
    String queueName = "queue_direct";
    String routingKey = "key.direct";
    
    channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
    channel.queueDeclare(queueName, true, false, false, null);
    channel.queueBind(queueName, exchangeName, routingKey);
    
    channel.basicConsume(queueName, true, new MyConsumer(channel));

    结果:

    -----------consume message----------
    consumerTag: amq.ctag-6UeNiGs1K-gMWbwvVn8F5A
    envelope: Envelope(deliveryTag=1, redeliver=false, exchange=exchange_direct, routingKey=key.direct)
    properties: #contentHeader<basic>(content-type=null, content-encoding=null, headers=null, delivery-mode=null, priority=null, correlation-id=null, reply-to=null, expiration=null, message-id=null, timestamp=null, type=null, user-id=null, app-id=null, cluster-id=null)
    body: send message by direct

    说明:

    Direct要求routingKey完全一致

    2.3、 topic

    Producer:

    String exchangeName = "exchange_topic";
    String routingKey1 = "user.save";
    String routingKey2 = "user.update";
    String routingKey3 = "user.delete.abc";
    //5 发送
    
    String msg = "Send Message By topic";
    channel.basicPublish(exchangeName, routingKey1 , null , msg.getBytes());
    channel.basicPublish(exchangeName, routingKey2 , null , msg.getBytes());
    channel.basicPublish(exchangeName, routingKey3 , null , msg.getBytes());

    Consumer:

    String exchangeName = "exchange_topic";
    String exchangeType = "topic";
    String queueName = "queue_topic";
    String routingKey = "user.*";
    
    channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
    channel.queueDeclare(queueName, true, false, false, null);
    channel.queueBind(queueName, exchangeName, routingKey);

    说明:

      Topic支持通配符匹配,#匹配一个或多个单词,*匹配一个单词

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  • 原文地址:https://www.cnblogs.com/huigelaile/p/10907523.html
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