Kafka3.0.0版本——消费者（独立消费者消费某一个主题中某个分区数据案例_

Kafka3.0.0版本——消费者（独立消费者消费某一个主题中某个分区数据案例__订阅分区）

news2024/9/24 17:18:08

一、独立消费者消费某一个主题中某个分区数据案例

1.1、案例需求

创建一个独立消费者，消费firstTopic主题 0 号分区的数据，所下图所示：

1.2、案例代码

生产者往firstTopic主题 0 号分区发送数据代码

package com.xz.kafka.producer;

import org.apache.kafka.clients.producer.*;
import org.apache.kafka.common.serialization.StringSerializer;
import java.util.Properties;

public class CustomProducerCallback {

    public static void main(String[] args) throws InterruptedException {

        //1、创建 kafka 生产者的配置对象
        Properties properties = new Properties();

        //2、给 kafka 配置对象添加配置信息：bootstrap.servers
        properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,"192.168.136.27:9092,192.168.136.28:9092,192.168.136.29:9092");

        //3、指定对应的key和value的序列化类型 key.serializer value.serializer
        properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
        properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,StringSerializer.class.getName());

        //4、创建 kafka 生产者对象
        KafkaProducer<String, String> kafkaProducer = new KafkaProducer<>(properties);

        //5、调用 send 方法,发送消息
        for (int i = 0; i < 5; i++) {
            kafkaProducer.send(new ProducerRecord<>("firstTopic", 0,"","hello kafka" + i), new Callback() {
                @Override
                public void onCompletion(RecordMetadata metadata, Exception exception) {
                    if (exception == null){
                        System.out.println("主题： "+metadata.topic() + " 分区： "+ metadata.partition());
                    }
                }
            });
            Thread.sleep(2);
        }

        // 3 关闭资源
        kafkaProducer.close();
    }
}

消费者消费firstTopic主题 0 分区数据代码

package com.xz.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.TopicPartition;
import org.apache.kafka.common.serialization.StringDeserializer;

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

public class CustomConsumerPartition {

    public static void main(String[] args) {
        // 配置
        Properties properties = new Properties();

        // 连接
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,"192.168.136.27:9092,192.168.136.28:9092,192.168.136.29:9092");

        // 反序列化
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());

        // 组id
        properties.put(ConsumerConfig.GROUP_ID_CONFIG,"test");

        // 1 创建一个消费者
        KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<>(properties);

        // 2 订阅主题对应的分区
        ArrayList<TopicPartition> topicPartitions = new ArrayList<>();
        topicPartitions.add(new TopicPartition("firstTopic",0));
        kafkaConsumer.assign(topicPartitions);

        // 3 消费数据
        while (true){

            ConsumerRecords<String, String> consumerRecords = kafkaConsumer.poll(Duration.ofSeconds(1));

            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord);
            }
        }
    }
}