1.需求：建立一個獨立消費者，消費 first 主題 0 號分割槽的資料。

2.在上篇隨筆的package包新建CustomConsumerPartition類

package com.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();
        //連線Kafka叢集
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,"hadoop102:9092");
        //反序列化
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,StringDeserializer.
 
class.getName());
        //GroupId（必須配置）
        properties.put(ConsumerConfig.GROUP_ID_CONFIG,"test");
        //建立消費者物件
        KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<>(properties);

        //topic分割槽陣列
        ArrayList<TopicPartition> topicPartitions = new ArrayList<>();
        topicPartitions.add(new TopicPartition("first",0));
        //訂閱topic對應的分割槽
        kafkaConsumer.assign(topicPartitions);
        //處理資料
        while (true){
            ConsumerRecords<String, String> consumerRecords = kafkaConsumer.poll(Duration.ofSeconds(1));
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord);
            }
        }
    }
}

3.在IDEA執行程式碼

4.在非同步傳送隨筆當中執行CustomProducerCallback()類程式碼（紅色部分為修改部分，指定分割槽為0，key為""）

//傳送資料
        for (int i = 0; i < 5; i++) {
            kafkaProducer.send(new ProducerRecord<>("first", 0,"","Kafka" + i), new Callback() {
                @Override
                public void onCompletion(RecordMetadata metadata, Exception exception) {
                    if (exception == null) {
                        System.out.println("主題：" + metadata.topic() + " 分割槽：" + metadata.partition());
                    }
                }
            });
        }

生產者傳送成功

檢視消費者

5.修改分割槽為1，檢視結果

for (int i = 0; i < 5; i++) {
            kafkaProducer.send(new ProducerRecord<>("first", 1,"","Kafka" + i), new Callback() {
                @Override
                public void onCompletion(RecordMetadata metadata, Exception exception) {
                    if (exception == null) {
                        System.out.println("主題：" + metadata.topic() + " 分割槽：" + metadata.partition());
                    }
                }
            });
        }

消費者無訊息收到