标签：sage message virtual stat 最大 rtu icp 声明 row
死信队列的简单介绍
利用dlx，当消息在一个队列中变成死信之后，它能被重新publish到另一个exchange，这个exchange就是dlx
消息变成死信的以下几种情况
消息被拒绝，并且requeue= false
消息ttl过期
队列达到最大的长度
dlx也是一个正常的exchange，和一般的exchange没什么区别，它能在任何的队列上被指定，实际上就是设置某个队列的属性。
当这个队列中有死信时，rabbitmq就会自动的将这个消息重新发布到设置的exchange上，进而被路由到另一个队列。
可以监听这个队列中消息做相应的处理，这个特性可以弥补rabbitMq3.0以前支持的immediate参数的功能。
消费端：
package com.flying.rabbitmq.api.dlx; import java.util.HashMap; import java.util.Map; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.QueueingConsumer; import com.rabbitmq.client.QueueingConsumer.Delivery; public class Consumer { public static void main(String[] args) throws Exception { ConnectionFactory connectionFactory = new ConnectionFactory(); connectionFactory.setHost("192.168.11.76"); connectionFactory.setPort(5672); connectionFactory.setVirtualHost("/"); Connection connection = connectionFactory.newConnection(); Channel channel = connection.createChannel(); // 这就是一个普通的交换机 和 队列 以及路由 String exchangeName = "test_dlx_exchange"; String routingKey = "dlx.#"; String queueName = "test_dlx_queue"; channel.exchangeDeclare(exchangeName, "topic", true, false, null); Map<String, Object> agruments = new HashMap<String, Object>(); agruments.put("x-dead-letter-exchange", "dlx.exchange"); //这个agruments属性，要设置到声明队列上 channel.queueDeclare(queueName, true, false, false, agruments); channel.queueBind(queueName, exchangeName, routingKey); //要进行死信队列的声明: channel.exchangeDeclare("dlx.exchange", "topic", true, false, null); channel.queueDeclare("dlx.queue", true, false, false, null); channel.queueBind("dlx.queue", "dlx.exchange", "#"); channel.basicConsume(queueName, true, new MyConsumer(channel)); } }
自定义消费端：
package com.flying.rabbitmq.api.dlx; import java.io.IOException; import com.rabbitmq.client.AMQP; import com.rabbitmq.client.Channel; import com.rabbitmq.client.DefaultConsumer; import com.rabbitmq.client.Envelope; 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)); } }
生产端：
package com.flying.rabbitmq.api.dlx; import com.rabbitmq.client.AMQP; import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; public class Producer { public static void main(String[] args) throws Exception { ConnectionFactory connectionFactory = new ConnectionFactory(); connectionFactory.setHost("192.168.11.76"); connectionFactory.setPort(5672); connectionFactory.setVirtualHost("/"); Connection connection = connectionFactory.newConnection(); Channel channel = connection.createChannel(); String exchange = "test_dlx_exchange"; String routingKey = "dlx.save"; String msg = "Hello RabbitMQ DLX Message"; for(int i =0; i<1; i ++){ AMQP.BasicProperties properties = new AMQP.BasicProperties.Builder() .deliveryMode(2) .contentEncoding("UTF-8") .expiration("10000") .build(); channel.basicPublish(exchange, routingKey, true, properties, msg.getBytes()); } } }
标签：sage message virtual stat 最大 rtu icp 声明 row
原文地址：https://www.cnblogs.com/lflying/p/11107435.html
