RabbitMq实现延迟队列功能

1、rabbitmq服务端打开延迟插件 （超过 4294967295毫秒 ≈ 1193 小时 ≈ 49.7 天  这个时间会立即触发）

注意：只有RabbitMQ 3.6.x以上才支持

在下载好之后，解压得到.ez结尾的插件包，将其复制到RabbitMQ安装目录下的plugins文件夹。

然后通过命令行启用该插件：

rabbitmq-plugins enable rabbitmq_delayed_message_exchange

该插件在通过上述命令启用后就可以直接使用，不需要重启。

2、添加依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-amqp</artifactId></dependency>

3、配置交换机和队列

@Configuration
public class DelayedConfig {public static String EXCHANGE_NAME = "delayed_exchange";public static String QUEUE_NAME = "delayed_queue";public static String KEY_NAME = "delayed_key";/*** 基于插件实现的交换机，必须是CustomExchange类型，标识这是一个延时类型的交换机*/@Bean()public CustomExchange delayedExchange(){Map<String,Object> params = new HashMap<>();params.put("x-delayed-type","direct");//参数1：交换机名字，参数2：交换机的类型，参数3：是否持久化，参数4：是否自动删除队列，参数5：交换机的额外参数设置return new CustomExchange(EXCHANGE_NAME,"x-delayed-message",true,false,params);}@Bean()public Queue delayedQueue(){return new Queue(QUEUE_NAME);}@Beanpublic Binding delayedBinding(){return BindingBuilder.bind(delayedQueue()).to(delayedExchange()).with(KEY_NAME).noargs();}}

 4、发送和接收消息

@GetMapping("/t5")public void t5(){Date date = new Date();System.out.println("发送时间:" + date.toString());//发送消息rabbitTemplate.convertAndSend(DelayedConfig.EXCHANGE_NAME,DelayedConfig.KEY_NAME,"1延迟消息wxm",msg->{msg.getMessageProperties().setHeader(MessageProperties.X_DELAY, 15552000000L);msg.getMessageProperties().setDeliveryMode(MessageDeliveryMode.PERSISTENT);return msg;});//发送消息rabbitTemplate.convertAndSend(DelayedConfig.EXCHANGE_NAME,DelayedConfig.KEY_NAME,"延迟消息wxm",msg->{msg.getMessageProperties().setDelay(10000);msg.getMessageProperties().setDeliveryMode(MessageDeliveryMode.PERSISTENT);return msg;});log.info("发送成功");}@RabbitHandler@RabbitListener(queues = "delayed_queue")public void getDelayed(Message message, Channel channel) throws Exception{Date date = new Date();String rightNow = date.toString();String msg = new String(message.getBody());// 手动应答System.out.println(message.getMessageProperties().getDeliveryTag());channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);System.out.println("接受成功："+msg+rightNow);}