RabbitMQ消息中间件(第三章)第二部分-笔记
Return消息机制
- Return Listener用于处理一些不可路由的消息
- 我们的消息生产者，通过指定一个Exchange和Routingkey，把消息送达到某一个队列中去，然后我们的消息监听队列，进行消费处理操作！
- 但是在某些情况下，如果我们在发送消息的时候，当前的exchange不存在或者指定的路由key路由不到，这个时候我们需要监听这个不可达的的消息，就要使用Return Listener!
- 在基础API中有一个关键的配置项：
- Mandatory:如果为true，则监听器会接收到路由不可达的消息，然后进行后续处理，如果为false，那么broker端自动删除该消息!默认为false
以下是实际代码操作
package com.cx.temp.common.rabbitmq.returnlistener; import com.alibaba.fastjson.JSONObject; import com.cx.temp.common.utils.JsonUtil; import com.rabbitmq.client.*; import net.sf.json.JSON; import java.io.IOException; /** * retunListener机制-生产端 */ public class Producer { public static void main(String[] args) throws Exception { //1 创建一个ConectionFacory ConnectionFactory connectionFactory = new ConnectionFactory(); connectionFactory.setHost("127.0.0.1"); connectionFactory.setPort(5672); connectionFactory.setVirtualHost("/test001"); connectionFactory.setUsername("root"); connectionFactory.setPassword("123456"); //2 通过连接工厂创建连接 Connection connection = connectionFactory.newConnection(); //3 通过connection创建一个Channel Channel channel = connection.createChannel(); //4 指定我们的消息投递模式：消息的确认模式 channel.confirmSelect(); String exchangeName = "test_return_exchange"; String routingKey = "return.save"; String routingKeyError = "abc.save"; //5 发送消息 //这里使用routingKey消费端可以正常收到消息，如果用routingKeyError，由于消费端声明的路由key是"return.#"，所以该消息不可达，则会被addReturnListener监听到 String msg = "Hello RabbitMQ send Return message!"; channel.basicPublish(exchangeName, routingKeyError, true, null, msg.getBytes()); //6 添加一个确认监听 //replyCode路由的响应码，replyText路由的响应文本才，exchange交换机， // routingKey路由key，properties发送时传的扩展参数，body具体内容 channel.addReturnListener(new ReturnListener() { @Override public void handleReturn(int replyCode, String replyText, String exchange, String routingKey, AMQP.BasicProperties properties, byte[] body) throws IOException { System.err.println("------handle return------"); System.err.println("replyCode:" + replyCode); System.err.println("replyText:" + replyText); System.err.println("exchange:" + exchange); System.err.println("routingKey:" + routingKey); System.err.println("properties:" + JSONObject.toJSON(properties)); System.err.println("body:" + new String(body)); } }); } }
package com.cx.temp.common.rabbitmq.returnlistener; import com.cx.temp.common.rabbitmq.quickstart.QueueingConsumer; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; /** * retunListener机制-消费端 */ public class Consumer { public static void main(String[] args) throws Exception { //1 创建一个ConectionFacory ConnectionFactory connectionFactory = new ConnectionFactory(); connectionFactory.setHost("127.0.0.1"); connectionFactory.setPort(5672); connectionFactory.setVirtualHost("/test001"); connectionFactory.setUsername("root"); connectionFactory.setPassword("123456"); //2 通过连接工厂创建连接 Connection connection = connectionFactory.newConnection(); //3 通过connection创建一个Channel Channel channel = connection.createChannel(); String exchangeName = "test_return_exchange"; String routingKey = "return.#"; String queueName = "test_refund_queue"; //声明交换机和队列然后进行绑定，最后指定路由KEY channel.exchangeDeclare(exchangeName, "topic", true, false, null); channel.queueDeclare(queueName, true, false, false, null); channel.queueBind(queueName, exchangeName, routingKey); //5 创建消费者 QueueingConsumer queueingConsumer = new QueueingConsumer(channel); channel.basicConsume(queueName, true, queueingConsumer); while (true) { QueueingConsumer.Delivery delivery = queueingConsumer.nextDelivery(); String msg = new String(delivery.getBody()); System.out.println("消费端:" + msg); } } }
消息端自定义监听
- 我们一般就是在代码中编写while循环，进行consumer.nextDelivery方法进行获取下一条消息，然后进行消息处理！
- 但是我们使用自定义的Consumer更加的方便，解耦性更加的强，也是在实际工作中常用的使用方式！
以下是实际代码操作
package com.cx.temp.common.rabbitmq.consumer; import com.alibaba.fastjson.JSONObject; import com.rabbitmq.client.*; import java.io.IOException; /** * 消息端自定义监听-生产端 */ public class Producer { public static void main(String[] args) throws Exception { //1 创建一个ConectionFacory ConnectionFactory connectionFactory = new ConnectionFactory(); connectionFactory.setHost("127.0.0.1"); connectionFactory.setPort(5672); connectionFactory.setVirtualHost("/test001"); connectionFactory.setUsername("root"); connectionFactory.setPassword("123456"); //2 通过连接工厂创建连接 Connection connection = connectionFactory.newConnection(); //3 通过connection创建一个Channel Channel channel = connection.createChannel(); //4 指定我们的消息投递模式：消息的确认模式 channel.confirmSelect(); String exchangeName = "test_consumer_exchange"; String routingKey = "consumer.save"; //5 发送消息 //这里使用routingKey消费端可以正常收到消息，如果用routingKeyError，由于消费端声明的路由key是"return.#"，所以该消息不可达，则会被addReturnListener监听到 String msg = "Hello RabbitMQ send Consumer message!"; for (int i = 0; i < 5; i++) { channel.basicPublish(exchangeName, routingKey, true, null, msg.getBytes()); } } }
package com.cx.temp.common.rabbitmq.consumer; import com.rabbitmq.client.AMQP; import com.rabbitmq.client.Channel; import com.rabbitmq.client.DefaultConsumer; import com.rabbitmq.client.Envelope; import java.io.IOException; /** * 自定义消费者 */ public class MyConsumer extends DefaultConsumer { public MyConsumer(Channel channel) { super(channel); } /** * * @param consumerTag 消费标签 * @param envelope 包含一些关键信息 * @param properties 附带扩展数据 * @param body 消息 * @throws IOException */ @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("consumerTag:" + consumerTag); System.err.println("body:" + new String(body)); } }
package com.cx.temp.common.rabbitmq.consumer; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; /** * 消息端自定义监听-消费端 */ public class Consumer { public static void main(String[] args) throws Exception { //1 创建一个ConectionFacory ConnectionFactory connectionFactory = new ConnectionFactory(); connectionFactory.setHost("127.0.0.1"); connectionFactory.setPort(5672); connectionFactory.setVirtualHost("/test001"); connectionFactory.setUsername("root"); connectionFactory.setPassword("123456"); //2 通过连接工厂创建连接 Connection connection = connectionFactory.newConnection(); //3 通过connection创建一个Channel Channel channel = connection.createChannel(); String exchangeName = "test_consumer_exchange"; String routingKey = "consumer.#"; String queueName = "test_consumer_queue"; //声明交换机和队列然后进行绑定，最后指定路由KEY channel.exchangeDeclare(exchangeName, "topic", true, false, null); channel.queueDeclare(queueName, true, false, false, null); channel.queueBind(queueName, exchangeName, routingKey); //5 创建消费者 channel.basicConsume(queueName, true, new MyConsumer(channel)); } }
