java使用kafka创建demo

1.创建java项目。在pom.xml文件中添加

<dependency>
    <groupId>org.apache.kafka</groupId>
    <artifactId>kafka-clients</artifactId>
    <version>0.10.2.0</version>
</dependency>

2.创建生产者代码

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 ProducerSend {
    public static void main(String args[]) {

        //1.参数配置：端口、缓冲内存、最大连接数、key序列化、value序列化等等（不是每一个非要配置）
        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");

        //2.创建生产者对象，并建立连接
        Producer<String, String> producer = new KafkaProducer<String,String>(props);
        try {
            //3.在my-topic主题下，发送消息
            for (int i = 0; i < 10000; i++) {
                System.out.println(Integer.toString(i));
                producer.send(new ProducerRecord<String, String>("my-topic", Integer.toString(i), Integer.toString(i)));
                Thread.sleep(500);
            }
        }
        catch (Exception e)
        {
            System.out.println("ERROR");
        }

        //4.关闭
        producer.close();

    }
}

3. 创建消费者代码

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 ConsumerReceive {
    public static void main(String args[]) {

        //1.参数配置:不是每一非得配置
        Properties props = new Properties();
        props.put("bootstrap.servers", "172.16.8.100:9092");
        props.put("auto.commit.interval.ms", "1000");
        //因为每一个消费者必须属于某一个消费者组，所以必须还设置group.id
        props.put("group.id", "test1");
        props.put("enable.auto.commit", "true");
        props.put("session.timeout.ms", "30000");
        props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");

        //2.创建消费者对象，并建立连接
        KafkaConsumer<String, String> consumer = new KafkaConsumer<String,String>(props);

        //3.设置从"my-topic"主题下拿取数据
        consumer.subscribe(Arrays.asList("my-topic"));

        //4.消费数据
        while (true) {
            //阻塞时间，从kafka中取出100毫秒的数据，有可能一次性去除0-n条
            ConsumerRecords<String, String> records = consumer.poll(100);
            //遍历
            for (ConsumerRecord<String, String> record : records)
                //打印结果
                //System.out.printf("offset = %d, key = %s, value = %s", record.offset(), record.key(), record.value());
                System.out.println("消费者消费的数据为："+record.value());
        }
    }
}