kafka java实例

启动zookeeper和Kafka server

    启动zookeeper：

    bin\windows\kafka-topics.bat --list --zookeeper localhost:2181

    启动Kafka Server：

    bin\windows\kafka-server-start.bat config/server.properties

    创建topic：

    bin\windows\kafka-topics.bat --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic mykafka

编写java程序

   maven pom文件添加依赖

                <dependency>
			<groupId>org.apache.kafka</groupId>
			<artifactId>kafka-clients</artifactId>
			<version>2.2.0</version>
		</dependency>

    生产者代码：

import java.util.Properties;

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;

public class MyProducer {
    public static void main(String[] args) {
        Properties properties = new Properties();
        //server地址
        properties.put("bootstrap.servers", "localhost:9092");
        properties.put("acks", "all");
        properties.put("retries", 0);
        properties.put("batch.size", 16384);
        properties.put("linger.ms", 1);
        properties.put("buffer.memory", 33554432);
        properties.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        properties.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        Producer<String, String> producer = null;
        try {
            producer = new KafkaProducer<String, String>(properties);
            for (int i = 0; i < 100; i++) {
                String msg = "Message " + i;
                producer.send(new ProducerRecord<String, String>("mykafka", msg));//mykafka为topic名称
                System.out.println("Sent:" + msg);
            }
        } catch (Exception e) {
            e.printStackTrace();

        } finally {
            producer.close();
        }

        System.out.println("发送完成！");
    }
}

    消费者代码：

import java.time.Duration;
import java.util.Arrays;
import java.util.Properties;

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


public class MyConsumer {
    public static void main(String[] args) {
        Properties properties = new Properties();
        //server地址
        properties.put("bootstrap.servers", "localhost:9092");
        properties.put("group.id", "group-2");
        properties.put("enable.auto.commit", "true");
        properties.put("auto.commit.interval.ms", "1000");
        properties.put("auto.offset.reset", "earliest");
        properties.put("session.timeout.ms", "30000");
        properties.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        properties.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");

        KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<>(properties);
        kafkaConsumer.subscribe(Arrays.asList("mykafka"));//mykafka为topic名称
        while (true) {
            ConsumerRecords<String, String> records = kafkaConsumer.poll(Duration.ofSeconds(10));
            for (ConsumerRecord<String, String> record : records) {
                System.out.printf("offset = %d, value = %s", record.offset(), record.value());
                System.out.println();
            }
        }
    }
}

运行生成者和消费者main方法即可发送接收数据。