SpringBoot+Rocketmq

@PostConstruct：用于在依赖关系注入完成之后需要执行的方法上，以执行任何初始化。此方法必须在将类放入服务之前调用。

@PreDestroy：在开发中我们如果要在关闭spring容器后释放一些资源，就在这个类中写一个被@PreDestroy的方法。今天就因为这个浪费了好长时间，mq的生产者启动之后没有被销毁，导致我用idea结束程序之后端口号依然被占用，每次再启动都要杀进程。。。

先把最简单的代码贴出来，只有最基本的发送接收功能

pom.xml

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

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

        <!-- https://mvnrepository.com/artifact/org.apache.rocketmq/rocketmq-common -->
        <dependency>
            <groupId>org.apache.rocketmq</groupId>
            <artifactId>rocketmq-common</artifactId>
            <version>4.3.</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.apache.rocketmq/rocketmq-client -->
        <dependency>
            <groupId>org.apache.rocketmq</groupId>
            <artifactId>rocketmq-client</artifactId>
            <version>4.3.</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.</version>
        </dependency>
    </dependencies>

application.properties

apache.rocketmq.consumer.PushConsumer=PushConsumer
apache.rocketmq.producer.producerGroup=Producer
apache.rocketmq.namesrvAddr=localhost:

TestController.java

package com.rmqspringtest.demo;

import com.rmqspringtest.demo.producer.ProducerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @Autowired
    private ProducerService producer;

    @RequestMapping("/push")
    public String pushMsg(String msg) {
        return producer.send("test1", "push", msg);
    }
}

ConsumerService.java

package com.rmqspringtest.demo.consumer;

import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.common.consumer.ConsumeFromWhere;
import org.apache.rocketmq.common.message.MessageExt;
import org.apache.rocketmq.remoting.common.RemotingHelper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;

@Component
public class ConsumerService {
    @Value("${apache.rocketmq.consumer.PushConsumer}")
    private String consumerGroup;
    @Value("${apache.rocketmq.namesrvAddr}")
    private String namesrvAddr;

    @PostConstruct
    public void defaultMQPushConsumer() {
        DefaultMQPushConsumer consumer = new DefaultMQPushConsumer(consumerGroup);
        consumer.setNamesrvAddr(namesrvAddr);
        try {
            consumer.subscribe("test1", "push");

            // 如果是第一次启动，从队列头部开始消费
            // 如果不是第一次启动，从上次消费的位置继续消费
            consumer.setConsumeFromWhere(ConsumeFromWhere.CONSUME_FROM_FIRST_OFFSET);

            consumer.registerMessageListener((MessageListenerConcurrently) (list, context) -> {
                try {
                    for (MessageExt messageExt : list) {
                        String messageBody = new String(messageExt.getBody(), RemotingHelper.DEFAULT_CHARSET);
                        System.out.println("[Consumer] msgID(" + messageExt.getMsgId() + ") msgBody : " + messageBody);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                    return ConsumeConcurrentlyStatus.RECONSUME_LATER;
                }
                return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
            });
            consumer.start();
            System.out.println("[Consumer 已启动]");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

ProducerService.java

package com.rmqspringtest.demo.producer;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;
import org.apache.rocketmq.remoting.common.RemotingHelper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

@Service
public class ProducerService {
    @Value("${apache.rocketmq.producer.producerGroup}")
    private String producerGroup;

    @Value("${apache.rocketmq.namesrvAddr}")
    private String namesrvAddr;

    private DefaultMQProducer producer;

    @PostConstruct
    public void initProducer() {
        producer = new DefaultMQProducer(producerGroup);
        producer.setNamesrvAddr(namesrvAddr);
        producer.setRetryTimesWhenSendFailed(3);
        try {
            producer.start();
            System.out.println("[Producer 已启动]");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public String send(String topic, String tags, String msg) {
        SendResult result = null;
        try {
            Message message = new Message(topic, tags, msg.getBytes(RemotingHelper.DEFAULT_CHARSET));
            result = producer.send(message);
            System.out.println("[Producer] msgID(" + result.getMsgId() + ") " + result.getSendStatus());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "{\"MsgId\":\"" + result.getMsgId() + "\"}";
    }

    @PreDestroy
    public void shutDownProducer() {
        if (producer != null) {
            producer.shutdown();
        }
    }
}

cmd中执行命令开启服务：

start mqnamesrv

start mqbroker -n 127.0.0.1:9876

发送请求：127.0.0.1:8080/push?msg=hello

ok

RocketMQTemplate 这玩意 看一下