application.properties添加如下配置
spring.rabbitmq.host=IP spring.rabbitmq.port=PORT spring.rabbitmq.username=USERNAME spring.rabbitmq.password=PASSWORD
实现延迟队列的功能
- 首先添加TTL配置类
@Configuration
public class TtlQueueConfig {
public static final String X_EXCHANGE = "X";
public static final String QUEUE_A = "QA";
public static final String QUEUE_B = "QB";
public static final String Y_DEAD_LETTER_EXCHANGE = "Y";
public static final String DEAD_LETTER_QUEUE = "QD";
public static final String QUEUE_C = "QC";
@Bean("queueC")
public Queue queueC() {
Map args = new HashMap<>(3);
//设置死信交换机
args.put("x-dead-letter-exchange",Y_DEAD_LETTER_EXCHANGE);
args.put("x-dead-letter-routing-key","YD");
//设置死信routingkey
return QueueBuilder.durable(QUEUE_C).withArguments(args).build();
}
@Bean
public Binding queuecBindingX(@Qualifier("queueC") Queue queueC,
@Qualifier("xExchange") DirectExchange xExchange){
return BindingBuilder.bind(queueC).to(xExchange).with("XC");
}
// 声明 xExchange
@Bean("xExchange")
public DirectExchange xExchange(){
return new DirectExchange(X_EXCHANGE);
}
// 声明 xExchange
@Bean("yExchange")
public DirectExchange yExchange(){
return new DirectExchange(Y_DEAD_LETTER_EXCHANGE);
}
//声明队列 A ttl 为 10s 并绑定到对应的死信交换机
@Bean("queueA")
public Queue queueA(){
Map args = new HashMap<>(3);
//声明当前队列绑定的死信交换机
args.put("x-dead-letter-exchange", Y_DEAD_LETTER_EXCHANGE);
//声明当前队列的死信路由 key
args.put("x-dead-letter-routing-key", "YD");
//声明队列的 TTL
args.put("x-message-ttl", 10000);
return QueueBuilder.durable(QUEUE_A).withArguments(args).build();
}
// 声明队列 A 绑定 X 交换机
@Bean
public Binding queueaBindingX(@Qualifier("queueA") Queue queueA,
@Qualifier("xExchange") DirectExchange xExchange){
return BindingBuilder.bind(queueA).to(xExchange).with("XA");
}
//声明队列 B ttl 为 40s 并绑定到对应的死信交换机
@Bean("queueB")
public Queue queueB(){
Map args = new HashMap<>(3);
//声明当前队列绑定的死信交换机
args.put("x-dead-letter-exchange", Y_DEAD_LETTER_EXCHANGE);
//声明当前队列的死信路由 key
args.put("x-dead-letter-routing-key", "YD");
//声明队列的 TTL
args.put("x-message-ttl", 40000);
return QueueBuilder.durable(QUEUE_B).withArguments(args).build();
}
//声明队列 B 绑定 X 交换机
@Bean
public Binding queuebBindingX(@Qualifier("queueB") Queue queue1B,
@Qualifier("xExchange") DirectExchange xExchange){
return BindingBuilder.bind(queue1B).to(xExchange).with("XB");
}
//声明死信队列 QD
@Bean("queueD")
public Queue queueD(){
return new Queue(DEAD_LETTER_QUEUE);
}
//声明死信队列 QD 绑定关系
@Bean
public Binding deadLetterBindingQAD(@Qualifier("queueD") Queue queueD,
@Qualifier("yExchange") DirectExchange yExchange){
return BindingBuilder.bind(queueD).to(yExchange).with("YD");
} }
- 在控制层编写生产者代码
@Slf4j
@RequestMapping("ttl")
@RestController
public class SendMsgController {
@Autowired
private RabbitTemplate rabbitTemplate;
@GetMapping("sendMsg/{message}")
public void sendMsg(@PathVariable String message){
log.info("当前时间：{},发送一条信息给两个 TTL 队列:{}", new Date(), message);
rabbitTemplate.convertAndSend("X", "XA", "消息来自 ttl 为 10S 的队列: "+message);
rabbitTemplate.convertAndSend("X", "XB", "消息来自 ttl 为 40S 的队列: "+message);
}
// 开始发消息
@GetMapping("sendExpirationMsg/{message}/{ttlTime}")
public void sendMsg(@PathVariable String message,@PathVariable String ttlTime) {
log.info("当前时间：{},发送一条时长{}毫秒 TTL 信息给队列 C:{}", new Date(),ttlTime, message);
rabbitTemplate.convertAndSend("X","XC",message,(Message msg)->{
//设置发送消息时候的延迟时长
msg.getMessageProperties().setExpiration(ttlTime);
return msg;
});
}
- 配置消费者监听器
@Slf4j
@Component
public class DeadLetterQueueConsumer {
@RabbitListener(queues = "QD")
public void receiveD(Message message, Channel channel) throws IOException {
String msg = new String(message.getBody());
log.info("当前时间：{},收到死信队列信息{}", new Date().toString(), msg);
}
}
以上代码存在一定的问题
如果使用在消息属性上设置 TTL 的方式，消
息可能并不会按时“死亡“，因为 RabbitMQ 只会检查第一个消息是否过期，如果过期则丢到死信队列，
如果第一个消息的延时时长很长，而第二个消息的延时时长很短，第二个消息并不会优先得到执行。
在官网上下载 https://www.rabbitmq.com/community-plugins.html，下载
rabbitmq_delayed_message_exchange 插件，然后解压放置到 RabbitMQ 的插件目录。
进入 RabbitMQ 的安装目录下的 plgins 目录，执行下面命令让该插件生效，然后重启 RabbitMQ
/usr/lib/rabbitmq/lib/rabbitmq_server-3.8.8/plugins
rabbitmq-plugins enable rabbitmq_delayed_message_exchange
添加延时插件以后,新增交换机多了一个Type类型
接下来开始编写代码，步骤跟上面一样
@Configuration
public class DelayedQueueConfig {
// 交换机
public static final String DELAYED_EXCHANGE_NAME = "delayed.exchange"
// 队列
public static final String DELAYED_QUEUE_NAME = "delayed.queue";
// routingkey
public static final String DELAYED_ROUTING_KEY = "delayed.routingkey";
@Bean
public Queue delayedQueue() {
return new Queue(DELAYED_QUEUE_NAME);
}
@Bean
public Binding delayedQueueBinding(@Qualifier("delayedQueue") Queue delayedQueue,
@Qualifier("delayedExchange") CustomExchange delayedExchange
) {
return BindingBuilder.bind(delayedQueue).to(delayedExchange).with(DELAYED_ROUTING_KEY).noargs();
}
@Bean
public CustomExchange delayedExchange() {
Map args = new HashMap<>();
args.put("x-delayed-type","direct");
return new CustomExchange(DELAYED_EXCHANGE_NAME,"x-delayed-message",true,false,args);
}
}
// 开始发消息，基于插件的消息，及延迟的时间
public static final String DELAYED_EXCHANGE_NAME = "delayed.exchange";
public static final String DELAYED_ROUTING_KEY = "delayed.routingkey";
@GetMapping("sendDelayMsg/{message}/{delayTime}")
public void sendMsg(@PathVariable String message,@PathVariable Integer delayTime) {
log.info(" 当 前 时 间 ： {}, 发送一条延迟 {} 毫秒的信息给队列 delayed.queue:{}", new
Date(),delayTime, message);
rabbitTemplate.convertAndSend(DelayedQueueConfig.DELAYED_QUEUE_NAME,DelayedQueueConfig.DELAYED_ROUTING_KEY,message,(Message msg)->{
//设置发送消息时候的延迟时长
msg.getMessageProperties().setDelay(delayTime);
return msg;
});
}
@Component
@Slf4j
public class DelayQueue {
@RabbitListener(queues = DelayedQueueConfig.DELAYED_QUEUE_NAME)
public void receive(Message message) {
String msg = new String(message.getBody());
log.info("当前时间：{},收到延时队列的消息：{}", new Date().toString(), msg);
}
}
测试结果，第二个消息先被消费掉，符合预期
暑期编程PK赛 得CSDN机械键盘等精美礼品！
