Spring Boot实战三：集成RabbitMQ，实现消息确认

Spring Boot集成RabbitMQ相比于Spring集成RabbitMQ简单很多，有兴趣了解Spring集成RabbitMQ的同学可以看我之前的《RabbitMQ学习笔记》系列的博客，特别是优先级消息队列，这里就不做重复介绍了。

在之前创建的Spring Boot项目（Spring Boot实战一：搭建Spring Boot开发环境）中加入依赖jar和RabbitMQ的配置（这里使用的是本地安装的RabbitMQ，需要安装的同学，可以参考我之前的博客：RabbitMQ学习笔记一：本地Windows环境安装RabbitMQ Server）:

在pom.xml中加入依赖jar：

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

在application.properties中加入RabbitMQ的配置信息：

# RabbitMQ config
spring.rabbitmq.host=127.0.0.1
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
spring.rabbitmq.virtualHost=/
spring.rabbitmq.publisher-confirms=true
spring.rabbitmq.publisher-returns=true
spring.rabbitmq.template.mandatory=true

 生产者SenderService：

package com.example.demo.service;

import javax.annotation.PostConstruct;

import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.rabbit.support.CorrelationData;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class SenderService implements RabbitTemplate.ConfirmCallback {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    @PostConstruct
    public void init()
    {
        rabbitTemplate.setConfirmCallback(this);
    }

    public void send(String msg)
    {
//        rabbitTemplate.convertAndSend("queue", msg); // 使用这个方法，则对应的消费者Listener中的process方法不能有返回值，否则会报错
        Object receive = rabbitTemplate.convertSendAndReceive("queue", msg);
        System.out.println("receive " + receive);
    }

    @Override
    public void confirm(CorrelationData correlationData, boolean ack, String cause)
    {
        if (ack) {
            System.out.println("消息发送确认成功");
        } else {
            System.out.println("消息发送确认失败:" + cause);

        }
    }
}

消费者Listener：

package com.example.demo.service;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

@Component
public class Listener {

    private static final Logger logger = LoggerFactory.getLogger(Listener.class);

    @RabbitListener(queues = "queue")
    public String process(String msg)
    {
        logger.info("Listener: " + msg);
        return msg;
    }
}

控制器RabbitmqController：

package com.example.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import com.example.demo.service.SenderService;

@RestController
public class RabbitmqController {

    @Autowired
    private SenderService sender;

    @GetMapping("/send")
    public String send(String msg)
    {
        sender.send(msg);
        return "Send OK.";
    }
}

启动访问：http://localhost:8080/send?msg=rabbitmq ，打印结果如下：

2017-08-14 14:15:34.588  INFO 6452 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2017-08-14 14:15:34.589  INFO 6452 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2017-08-14 14:15:34.614  INFO 6452 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 25 ms
消息发送确认成功
2017-08-14 14:15:34.699  INFO 6452 --- [cTaskExecutor-1] com.example.demo.service.Listener        : Listener: rabbitmq
receive rabbitmq

PS：需要在RabbitMQ Server创建对应的队列，不了解RabbitMQ的可以参考我之前的《RabbitMQ学习笔记》系列的博客。