kafka-初识kafka-第一个java程序-小白笔记（一）

1 kafka第一个java程序

基于SpringBoot实现，对连接参数的设置进行了优化。

1.1 新建Spring Boot项目，添加依赖

       <properties>
         <java.version>1.8</java.version>
          <kafka.version>2.0.0</kafka.version>
         <scala.version>2.11</scala.version>
       </properties>

        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-clients</artifactId>
            <version>${kafka.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka_${scala.version}</artifactId>
            <version>${kafka.version}</version>
        </dependency>

1.2 生产者代码实现

 对参数的配置进行了优化

package xb.study.kafka.producer;

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

import java.util.Properties;

public class ProducerStart {
    private static String brokerList="10.251.80.151:9092";
    private static String topic="test";
    public static void main(String[] args) {
        Properties properties=new Properties();
        //设置key 序列化器
        //properties.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());//使用工具类避免写错
        //设置重试测试
        properties.put(ProducerConfig.RETRIES_CONFIG,2);
        //设置值序列化器
        //properties.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
        //设置集群地址
        //properties.put("bootstrap.servers",brokerList);
        properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,brokerList);

        KafkaProducer<String,String> producer=new KafkaProducer<String, String>(properties);
        ProducerRecord<String,String> record=new ProducerRecord<>(topic,"kafka-demo","Hello kafka!");
        try{
            producer.send(record);
        }catch (Exception e){
           e.printStackTrace();
        }
        producer.close();



    }
}

1.3 消费者代码实现

package xb.study.kafka.consumer;

import org.apache.kafka.clients.consumer.ConsumerConfig;
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.time.Duration;
import java.util.Collections;
import java.util.Properties;

/**
 * 消费者
 */
public class ConsumerStart {
    private static final String brokerList="10.251.80.151:9092";
    private static final String topic="test";
    private static final String groupId="group.demo";
    public static void main(String[] args) {
        try {

            Properties props = new Properties();
            //props.put("group.id", groupId);
            props.put(ConsumerConfig.GROUP_ID_CONFIG,groupId);
            //props.put("bootstrap.servers", brokerList);
            props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, brokerList);
            //props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
            props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
            //props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
            props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
            KafkaConsumer consumer= new KafkaConsumer<String,String>(props);
            consumer.subscribe(Collections.singletonList(topic));
            while (true){
                ConsumerRecords<String,String> records=consumer.poll(Duration.ofMillis(3000));
                for(ConsumerRecord<String,String> record:records){
                    System.out.println(record.value());
                }

            }
        }catch (Exception e){
            e.printStackTrace();

        }
    }
}