RocketMQ源码分析：（二）消息发送的三种方式

1. 同步传输（可靠，适用于重要的通知消息、短信通知、短信营销系统等）

package com.miaoying.rocketmq.client;

import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendCallback;
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.Component;
import org.springframework.util.StopWatch;

import javax.annotation.PostConstruct;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

/**
 * 　@Description:
 * 　@author miaoying
 * 　@date 2019/2/27
 */
@Slf4j
@Component
public class RocketMQClient {
    /**
     * 生产者的组名
     */
    @Value("${apache.rocketmq.producer.producerGroup}")
    private String producerGroup;

    /**
     * NameServer 地址
     */
    @Value("${apache.rocketmq.namesrvAddr}")
    private String namesrvAddr;

    @PostConstruct
    public void defaultMQProducer() throws InterruptedException {
        DefaultMQProducer producer = new DefaultMQProducer(producerGroup);
        producer.setNamesrvAddr(namesrvAddr);

        int messageCount = 10000;
        final CountDownLatch countDownLatch = new CountDownLatch(messageCount);

        try {
            producer.start();
            producer.setRetryTimesWhenSendAsyncFailed(0);

            for (int i = 0; i < messageCount; i++) {
                Message message = new Message("TopicMiaoAsync", "push", "keyTest", ("message" + i).getBytes(RemotingHelper.DEFAULT_CHARSET));
                SendResult sendResult = producer.send(message);
                log.info("MsgId = " + sendResult.getMsgId() + " , offsetMsgId = " + sendResult.getOffsetMsgId());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        countDownLatch.await(5, TimeUnit.SECONDS);
        producer.shutdown();
    }
}

2. 异步传输（一般用于响应时间敏感的业务场景）

package com.miaoying.rocketmq.client;

import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendCallback;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;
import org.apache.rocketmq.remoting.common.RemotingHelper;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

@Slf4j
public class AsyncRocketMQClient {

    public static void main(String[] args) throws InterruptedException {
        DefaultMQProducer producer = new DefaultMQProducer("Producer");
        producer.setNamesrvAddr("localhost:9876");

        int messageCount = 10000;
        final CountDownLatch countDownLatch = new CountDownLatch(messageCount);

        try {
            producer.start();
            producer.setRetryTimesWhenSendAsyncFailed(0);

            for (int i = 0; i < messageCount; i++) {
                Message message = new Message("TopicMiaoAsync", "push", "keyTest", ("message" + i).getBytes(RemotingHelper.DEFAULT_CHARSET));
                producer.send(message, new SendCallback() {
                    @Override
                    public void onSuccess(SendResult result) {
                        countDownLatch.countDown();
                        // 对于客户端来说msgd是由客户端producer生成的，offsetMsgId是由服务端broker生成的
                        log.info("MsgId : " + result.getMsgId() + " , offsetMsgId : " + result.getOffsetMsgId() + " , send status : " + result.getSendStatus());
                    }

                    @Override
                    public void onException(Throwable e) {
                        countDownLatch.countDown();
                        log.error("send message to rocketmq fail. " + e.getMessage());
                    }
                });
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        countDownLatch.await(5, TimeUnit.SECONDS);
        producer.shutdown();
    }
}

3. 单向传输（用于需要中等可靠性的情况，例如日志收集）

package com.miaoying.rocketmq.client;

import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendCallback;
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.Component;
import org.springframework.util.StopWatch;

import javax.annotation.PostConstruct;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

/**
 * 　@Description:
 * 　@author miaoying
 * 　@date 2019/2/27
 */
@Slf4j
@Component
public class RocketMQClient {
    /**
     * 生产者的组名
     */
    @Value("${apache.rocketmq.producer.producerGroup}")
    private String producerGroup;

    /**
     * NameServer 地址
     */
    @Value("${apache.rocketmq.namesrvAddr}")
    private String namesrvAddr;

    @PostConstruct
    public void defaultMQProducer() throws InterruptedException {
        DefaultMQProducer producer = new DefaultMQProducer(producerGroup);
        producer.setNamesrvAddr(namesrvAddr);

        int messageCount = 10000;
        final CountDownLatch countDownLatch = new CountDownLatch(messageCount);

        try {
            producer.start();
            producer.setRetryTimesWhenSendAsyncFailed(0);

            for (int i = 0; i < messageCount; i++) {
                Message message = new Message("TopicMiaoAsync", "push", "keyTest", ("message" + i).getBytes(RemotingHelper.DEFAULT_CHARSET));
                producer.sendOneway(message);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        countDownLatch.await(5, TimeUnit.SECONDS);
        producer.shutdown();
    }
}