Kafka生产消费数据的Java入门Demo

一.创建生产者。

import org.apache.kafka.clients.producer.Callback;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;

import java.util.Properties;
import java.util.concurrent.Future;


public class MyKafkaProducer implements Runnable{

    private static KafkaProducer<String, String> kafkaProducer;

    public MyKafkaProducer() {
        Properties properties = new Properties();
        properties.put("bootstrap.servers","xxx.xx.xx.xxx:9092");
        properties.put("key.serializer","org.apache.kafka.common.serialization.StringSerializer");
        properties.put("value.serializer","org.apache.kafka.common.serialization.StringSerializer");
        properties.put("acks","0");
        properties.put("retries","0");
        properties.put("batch.size","16384");
        kafkaProducer = new KafkaProducer<>(properties);
    }

    @Override
    public void run() {
        try {
            main(null);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        System.out.println(kafkaProducer);
        MyKafkaProducer myKafkaProducer = new MyKafkaProducer();
        System.out.println(kafkaProducer);
        String topic = "topic1";
        for (int i = 200; i < 300; i++) {
            String message = "hello kafka 哈哈哈 i="+i;
            ProducerRecord<String, String> producerRecord = new ProducerRecord<String, String>(topic,message);
            Future<RecordMetadata> send = kafkaProducer.send(producerRecord, new Callback() {
                @Override
                public void onCompletion(RecordMetadata recordMetadata, Exception e) {
                    if(e != null){
                        e.printStackTrace();
                    }
                    System.out.println("===========partition======"+recordMetadata.partition()+"===========offset=========="+recordMetadata.offset());
                }
            });
        }
        Thread.sleep(3000);
    }

}

二.创建消费者。

import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;

import java.util.Arrays;
import java.util.Properties;


public class MyKafkaConsumer implements Runnable {

    private static KafkaConsumer<String,String> kafkaConsumer;

    public MyKafkaConsumer() {
        Properties properties = new Properties();
        properties.put("bootstrap.servers","xxx.xx.xx.xxx:9092");
        properties.put("key.deserializer","org.apache.kafka.common.serialization.StringDeserializer");
        properties.put("value.deserializer","org.apache.kafka.common.serialization.StringDeserializer");
        properties.put("group.id","group2");
        properties.put("enable.auto.commit","true");
        properties.put("auto.commit.interval.ms", "1000");
        properties.put("session.timeout.ms", "30000");
        properties.put("auto.offset.reset", "earliest");
        kafkaConsumer = new KafkaConsumer<String, String>(properties);
    }

    @Override
    public void run() {
        main(null);
    }

    public static void main(String[] args) {
        MyKafkaConsumer myKafkaConsumer = new MyKafkaConsumer();
        kafkaConsumer.subscribe(Arrays.asList("topic1"));//订阅
        while(true){
            ConsumerRecords<String, String> poll = kafkaConsumer.poll(1000);//检验
            for (ConsumerRecord<String,String> record : poll) {
                System.out.println("=========="+"offset="+record.offset()+",value="+record.value());
            }
        }
    }
}

三.启动线程，生产者生产数据，同时消费者消费数据。

import static java.lang.Thread.*;

public class MyKafkaBroker {

    public static void main(String[] args) throws InterruptedException {
        Thread producer = new Thread(new MyKafkaProducer());
        producer.start();
        sleep(3000);
        Thread consumer = new Thread(new MyKafkaConsumer());
        consumer.start();
    }

}