Java实现Kafka的生产者、消费者

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一、生产者

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerRecord;
import java.util.Properties;

public class SimpleKafkaProducer {
    private static KafkaProducer<String, String> producer;
    private final static String TOPIC = "adienTest2";
    public SimpleKafkaProducer(){
        Properties props = new Properties();
        props.put("bootstrap.servers", "localhost:9092");
        props.put("acks", "all");
        props.put("retries", 0);
        props.put("batch.size", 16384);
        props.put("linger.ms", 1);
        props.put("buffer.memory", 33554432);
        props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        //设置分区类,根据key进行数据分区
        producer = new KafkaProducer<String, String>(props);
    }
    public void produce(){
        for (int i = 30;i<40;i++){
            String key = String.valueOf(i);
            String data = "hello kafka message："+key;
            producer.send(new ProducerRecord<String, String>(TOPIC,key,data));
            System.out.println(data);
        }
        producer.close();
    }

    public static void main(String[] args) {
        new SimpleKafkaProducer().produce();
    }
}

二、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 org.apache.log4j.Logger;

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

public class SimpleKafkaConsumer {
    private static KafkaConsumer<String, String> consumer;
    private final static String TOPIC = "adienTest2"
    public SimpleKafkaConsumer(){
        Properties props = new Properties();
        props.put("bootstrap.servers", "localhost:9092");
        //每个消费者分配独立的组号
        props.put("group.id", "test2");
        //如果value合法，则自动提交偏移量
        props.put("enable.auto.commit", "true");
        //设置多久一次更新被消费消息的偏移量
        props.put("auto.commit.interval.ms", "1000");
        //设置会话响应的时间，超过这个时间kafka可以选择放弃消费或者消费下一条消息
        props.put("session.timeout.ms", "30000");
        //自动重置offset
        props.put("auto.offset.reset","earliest");
        props.put("key.deserializer",
                "org.apache.kafka.common.serialization.StringDeserializer");
        props.put("value.deserializer",
                "org.apache.kafka.common.serialization.StringDeserializer");
        consumer = new KafkaConsumer<String, String>(props);
    }

    public void consume(){
        consumer.subscribe(Arrays.asList(TOPIC));
        while (true) {
            ConsumerRecords<String, String> records = consumer.poll(100);
            for (ConsumerRecord<String, String> record : records){
                System.out.printf("offset = %d, key = %s, value = %s",record.offset(), record.key(), record.value());
                System.out.println();
            }
        }
    }

    public static void main(String[] args) {
        new SimpleKafkaConsumer().consume();
    }
}

三、运行
1、该生产者、消费者是运行本地搭建的kafka，所以先用命令行启动zookeeper，再启动kafka服务，还要创建本例中使用的topic：adienTest2
2、运行生产者代码，运行结果如下：

3、运行消费者代码，运行结果如下：