mq延迟队列代码实现
时间: 2023-11-21 21:54:20 浏览: 146
Rabbitmq延迟队列实现定时任务的方法
MQ延迟队列的代码实现可以分为以下几个步骤:
1. 创建延迟队列
在RabbitMQ中,需要先安装rabbitmq_delayed_message_exchange插件,然后创建一个类型为x-delayed-message的Exchange,代码如下:
```java
Map<String, Object> args = new HashMap<>();
args.put("x-delayed-type", "direct");
channel.exchangeDeclare("delayed_exchange", "x-delayed-message", true, false, args);
```
2. 发送延迟消息
在发送消息时,需要设置消息的过期时间(TTL)和消息头中的x-delay属性,代码如下:
```java
AMQP.BasicProperties.Builder builder = new AMQP.BasicProperties.Builder();
builder.expiration("10000");//设置消息的过期时间为10秒
builder.headers(Collections.singletonMap("x-delay", 5000));//设置消息头中的x-delay属性为5秒
channel.basicPublish("delayed_exchange", "delayed_queue", builder.build(), "Hello, delayed message!".getBytes());
```
3. 接收延迟消息
在接收消息时,需要创建一个绑定了延迟队列的消费者,代码如下:
```java
channel.queueBind("delayed_queue", "delayed_exchange", "delayed_queue");
channel.basicConsume("delayed_queue", true, new DefaultConsumer(channel) {
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
String message = new String(body, "UTF-8");
System.out.println("Received delayed message: " + message);
}
});
```
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