Kafka2.6.0生产消费示例代码

前提：需要Kafka集群。

创建一个简单的gradle项目

build.gradle配置信息

buildscript {
    repositories {
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
        maven{ url 'http://maven.aliyun.com/nexus/content/repositories/jcenter'}
    }
}

plugins {
    id 'java'
}

version 'unspecified'

sourceCompatibility = 1.8

repositories {
    mavenCentral()
}

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.12'
    compile group: 'org.apache.kafka', name: 'kafka_2.12', version: '2.6.0'
    compile group: 'org.apache.kafka', name: 'kafka-clients', version: '2.6.0'
}

allprojects {
    repositories {
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
        maven{ url 'http://maven.aliyun.com/nexus/content/repositories/jcenter'}
    }
}

创建生产者类

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.serialization.StringDeserializer;

import java.util.Properties;
import java.util.Random;

public class MsgKafkaProducer extends Thread {

    private final KafkaProducer<Integer, String> producer;
    private final String topic;

    public MsgKafkaProducer(String topic) {

        Properties props = new Properties();
        props.put("metadata.broker.list", "192.168.88.62:9092");
        props.put("bootstrap.servers", "192.168.88.62:9092");
        props.put("retries", 0);
        props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        producer = new KafkaProducer<>(props);
        this.topic = topic;
    }

    @Override
    public void run() {
        int messageNo = 1;
        Random random = new Random();
        for (int i = 0; i < 1000; i++) {
            String messageStr = "Message" + random.nextInt(10000) + " " + messageNo;
            System.out.println("Send:" + messageStr);
            producer.send(new ProducerRecord<>(topic, messageStr));
            messageNo++;
        }
    }

    public static void main(String[] args) {
        MsgKafkaProducer producerThread = new MsgKafkaProducer("kafka_test");
        producerThread.start();
    }

}

创建消费者类

import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.serialization.StringDeserializer;

import java.util.Collections;
import java.util.Properties;

public class MsgKafkaConsumer implements Runnable {

    private final KafkaConsumer<String, String> consumer;
    private static final String GROUP_ID = "groupA";

    public MsgKafkaConsumer(String topicName) {
        Properties props = new Properties();
        props.put("bootstrap.servers", "192.168.88.62:9092");
        props.put("group.id", GROUP_ID);
        props.put("enable.auto.commit", "true");
        props.put("auto.commit.interval.ms", "1000");
        props.put("session.timeout.ms", "30000");
        props.put("auto.offset.reset", "earliest");
        props.put("key.deserializer", StringDeserializer.class.getName());
        props.put("value.deserializer", StringDeserializer.class.getName());
        this.consumer = new KafkaConsumer<String, String>(props);
        this.consumer.subscribe(Collections.singletonList(topicName));
    }

    @Override
    public void run() {
        int messageNo = 1;
        try {
            while (true) {
                ConsumerRecords<String, String> msgList = consumer.poll(1000);
                if (null != msgList && msgList.count() > 0) {
                    for (ConsumerRecord<String, String> record : msgList) {
                        System.out.println("=> topic : kafka_test " + messageNo + "=> receive: key => " + record.key() + ", value => " + record.value() + " offset => " + record.offset());
                        messageNo++;
                    }
                } else {
                    Thread.sleep(1000);
                }
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            consumer.close();
        }
    }

    public static void main(String args[]) {
        MsgKafkaConsumer test1 = new MsgKafkaConsumer("kafka_test");
        Thread thread1 = new Thread(test1);
        thread1.start();
    }
}