这里要根据自身需求开发，我这里只举一个简单的例子，就是几个分区就启动几个consumer，一一对应。
三个类：
Main：
public static void main(String[] args) {
    String bootstrapServers = "kafka01:9092，kafka02:9092";
    String groupId = "test";
    String topic = "testtopic";
    int consumerNum = 3;
    ConsumerGroup cg = new ConsumerGroup(consumerNum,bootstrapServers,groupId,topic);
    cg.execute();
}
import java.util.ArrayList;
import java.util.List;
public class ConsumerGroup {
  private List<ConsumerRunnable> consumers;
  public ConsumerGroup(int consumerNum,String bootstrapServers,String groupId,String topic){
    consumers = new ArrayList<>(consumerNum);
    for(int i=0;i < consumerNum;i++){
      ConsumerRunnable ConsumerRunnable = new ConsumerRunnable(bootstrapServers,groupId,topic);
      consumers.add(ConsumerRunnable);
    }
  }
  public void execute(){
    for(ConsumerRunnable consumerRunnable:consumers){
      new Thread(consumerRunnable).start();
    }
  }
}
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 ConsumerRunnable implements Runnable{
  private final KafkaConsumer<String,String> consumer;
  public ConsumerRunnable(String bootstrapServers,String groupId,String topic){
    Properties props = new Properties();
      props.put("bootstrap.servers", bootstrapServers);
      props.put("group.id", groupId);
      props.put("enable.auto.commit", "true");
      props.put("auto.commit.interval.ms", "1000");
      props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
      props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
      props.put("auto.offset.reset","earliest");
      this.consumer = new KafkaConsumer<>(props);
      consumer.subscribe(Arrays.asList(topic));
  }
  @Override
  public void run() {
      while (true) {
          ConsumerRecords<String, String> records = consumer.poll(10);
          for (ConsumerRecord<String, String> record : records) {
            System.out.printf("offset = %d, key = %s, value = %s%n", record.offset(), record.key(), record.value());
          }
      }
  }
}