Scheduled/Delay messaging in Spring AMQP RabbitMq

2019-02-18 08:03发布

问题:

I am struggling hard to find out the way for scheduled/Delaying messages in Spring AMQP/Rabbit MQ.
After hell lot of searching still I am not able to do that in Spring AMQP. Can someone please tell me how to do x-delay in Spring AMQP.
I want to Delay a message if some exception occurs in the consumer side. RabbitMQ says to add x-delay and install the plugin which I have already done, but still messages is comming immediately without any delay



I am getting this in message
Received <(Body:'[B@60a4ae5f(byte[26])'MessageProperties [headers={x-delay=15000}

 @Bean
ConnectionFactory connectionFactory(){

    CachingConnectionFactory connectionFactory=new CachingConnectionFactory("127.0.0.1");
    connectionFactory.setUsername("guest");
    connectionFactory.setPassword("guest");
    connectionFactory.setPort(1500);
    connectionFactory.setPublisherReturns(true);
    return connectionFactory;

}

@Bean
Binding binding(@Qualifier("queue")Queue queue, DirectExchange exchange) {
    return new Binding(queue.getName(), Binding.DestinationType.QUEUE, exchange.getName(), queue.getName(), null);
    //return BindingBuilder.bind(queue).to(exchange).with(queueName);   
}

@Bean
DirectExchange exchange() {
    DirectExchange exchange=new DirectExchange("delay-exchange");
    return exchange;
}

Consumer---
@Override

public void onMessage(Message message, Channel channel) throws Exception {

    System.out.println("Received <" + message+ ">" +rabbitTemplate);

    if(i==1){
        AMQP.BasicProperties.Builder props = new AMQP.BasicProperties.Builder();
        Map<String,Object> headers = message.getMessageProperties().getHeaders();
        headers.put("x-delay", 15000);
        props.headers(headers);
        i++;
        channel.basicPublish(message.getMessageProperties().getReceivedExchange(), message.getMessageProperties().getReceivedRoutingKey(),
                props.build(), message.getBody());
    }
    }

回答1:

First of all looks like you don't follow with the Scheduling Messages with RabbitMQ article:

To use the Delayed Message Exchange you just need to declare an exchange providing the "x-delayed-message" exchange type as follows:

Map<String, Object> args = new HashMap<String, Object>();
args.put("x-delayed-type", "direct");
channel.exchangeDeclare("my-exchange", "x-delayed-message", true, false, args);

I'd say the same can be achieved with the Spring AMQP:

@Bean
CustomExchange delayExchange() {
    Map<String, Object> args = new HashMap<String, Object>();
    args.put("x-delayed-type", "direct");
    return new CustomExchange("my-exchange", "x-delayed-message", true, false, args);
}

Another concern that you really should publish messages to that delay-exchange, not any other. Again: that is mentioned in that doc anyway.

UPDATE

Since Spring AMQP 1.6 the Delayed Messages is supported as out-of-the-box feature: https://spring.io/blog/2016/02/16/spring-amqp-1-6-0-milestone-1-and-1-5-4-available.