这篇文章带你了解怎么整合RabbitMQ服务器,并且通过它怎么去发送和接收消息。我将构建一个springboot工程,通过RabbitTemplate去通过MessageListenerAdapter去订阅一个POJO类型的消息。
准备工作
15min
IDEA
maven 3.0
在开始构建项目之前,机器需要安装rabbitmq,你可以去官网下载,http://www.rabbitmq.com/download.html ,如果你是用的Mac(程序员都应该用mac吧),你可以这样下载:
brew install rabbitmq
安装完成后开启服务器:
rabbitmq-server
开启服务器成功,你可以看到以下信息:
RabbitMQ 3.1.3. Copyright (C) 2007-2013 VMware, Inc. ## ## Licensed under the MPL. See http://www.rabbitmq.com/ ## ## ########## Logs: /usr/local/var/log/rabbitmq/rabbit@localhost.log ###### ## /usr/local/var/log/rabbitmq/rabbit@localhost-sasl.log ########## Starting broker... completed with 6 plugins.
构建工程
构架一个SpringBoot工程,其pom文件依赖加上spring-boot-starter-amqp的起步依赖:
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-amqp</artifactId> </dependency>
创建消息接收者
在任何的消息队列程序中,你需要创建一个消息接收者,用于响应发送的消息。
@Component public class Receiver { private CountDownLatch latch = new CountDownLatch(1); public void receiveMessage(String message) { System.out.println("Received <" + message + ">"); latch.countDown(); } public CountDownLatch getLatch() { return latch; } }
消息接收者是一个简单的POJO类,它定义了一个方法去接收消息,当你注册它去接收消息,你可以给它取任何的名字。其中,它有CountDownLatch这样的一个类,它是用于告诉发送者消息已经收到了,你不需要在应用程序中具体实现它,只需要latch.countDown()就行了。
创建消息监听,并发送一条消息
在spring程序中,RabbitTemplate提供了发送消息和接收消息的所有方法。你只需简单的配置下就行了:
需要一个消息监听容器
声明一个quene,一个exchange,并且绑定它们
一个组件去发送消息
代码清单如下:
package com.forezp; import com.forezp.message.Receiver; import org.springframework.amqp.core.Binding; import org.springframework.amqp.core.BindingBuilder; import org.springframework.amqp.core.Queue; import org.springframework.amqp.core.TopicExchange; import org.springframework.amqp.rabbit.connection.ConnectionFactory; import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer; import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.Bean; @SpringBootApplication public class SpringbootRabbitmqApplication { final static String queueName = "spring-boot"; @Bean Queue queue() { return new Queue(queueName, false); } @Bean TopicExchange exchange() { return new TopicExchange("spring-boot-exchange"); } @Bean Binding binding(Queue queue, TopicExchange exchange) { return BindingBuilder.bind(queue).to(exchange).with(queueName); } @Bean SimpleMessageListenerContainer container(ConnectionFactory connectionFactory, MessageListenerAdapter listenerAdapter) { SimpleMessageListenerContainer container = new SimpleMessageListenerContainer(); container.setConnectionFactory(connectionFactory); container.setQueueNames(queueName); container.setMessageListener(listenerAdapter); return container; } @Bean MessageListenerAdapter listenerAdapter(Receiver receiver) { return new MessageListenerAdapter(receiver, "receiveMessage"); } public static void main(String[] args) { SpringApplication.run(SpringbootRabbitmqApplication.class, args); } }
创建一个测试方法:
@Component public class Runner implements CommandLineRunner { private final RabbitTemplate rabbitTemplate; private final Receiver receiver; private final ConfigurableApplicationContext context; public Runner(Receiver receiver, RabbitTemplate rabbitTemplate, ConfigurableApplicationContext context) { this.receiver = receiver; this.rabbitTemplate = rabbitTemplate; this.context = context; } @Override public void run(String... args) throws Exception { System.out.println("Sending message..."); rabbitTemplate.convertAndSend(Application.queueName, "Hello from RabbitMQ!"); receiver.getLatch().await(10000, TimeUnit.MILLISECONDS); context.close(); } }
启动程序,你会发现控制台打印:
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