创建项目

创建 maven 项目，pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.rocketmq.test</groupId>
    <artifactId>simpledemo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.rocketmq</groupId>
            <artifactId>rocketmq-client</artifactId>
            <version>4.3.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

代码

1. Producer

package com.rocketmq.test;

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;

public class SyncProducer {
    public static void main(String[] args) throws Exception {
        
        // 实例化 producer，指定一个唯一的组名
        DefaultMQProducer producer = new
            DefaultMQProducer("please_rename_unique_group_name");
        
        // 指定 name server 地址
        producer.setNamesrvAddr("localhost:9876");
        
        // 启动 producer
        producer.start();
        
        for (int i = 0; i < 100; i++) {
            
            // 创建消息实例, 指定 topic, tag 和 message 
            Message msg = new Message("TopicTest",
                "TagA",
                ("Hello RocketMQ " +
                    i).getBytes(RemotingHelper.DEFAULT_CHARSET)
            );
            
            // 发送消息，同步方式，等待返回结果
            SendResult sendResult = producer.send(msg);
            System.out.printf("%s%n", sendResult);
        }
        
        // 关闭
        producer.shutdown();
    }
}

2. Consumer

package com.rocketmq.test;

import java.util.List;

import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.client.exception.MQClientException;
import org.apache.rocketmq.common.message.MessageExt;

public class Consumer {
    public static void main(String[] args) throws InterruptedException, MQClientException {

        // 实例化 consumer，指定 consumer 组名
        DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("please_rename_unique_group_name");

        // 指定 name server 
        consumer.setNamesrvAddr("localhost:9876");

        // 订阅1个或多个topic
        consumer.subscribe("TopicTest", "*");
        
        // 注册回调，当收到消息时执行
        consumer.registerMessageListener(new MessageListenerConcurrently() {

            public ConsumeConcurrentlyStatus consumeMessage(final List<MessageExt> msgs,
                    final ConsumeConcurrentlyContext context) {
                System.out.printf("%s Receive New Messages: %s %n", Thread.currentThread().getName(), msgs);
                
                return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
            }
        });

        // 启动 consumer
        consumer.start();

        System.out.printf("Consumer Started.%n");
    }
}

运行

mvn exec:java -Dexec.mainClass="com.rocketmq.test.SyncProducer"

mvn exec:java -Dexec.mainClass="com.rocketmq.test.Consumer"