Java中kafka自定义分区类和拦截器的实现方法

import org.apache.kafka.clients.producer.Partitioner;
import org.apache.kafka.common.Cluster;

import java.util.Map;

public class CustomPartitioner implements Partitioner {

  /**
   *
   * @param topic 当前的发送的topic
   * @param key  当前的key值
   * @param keyBytes 当前的key的字节数组
   * @param value 当前的value值
   * @param valueBytes 当前的value的字节数组
   * @param cluster
   * @return
   */
  @Override
  public int partition(String topic, Object key, byte[] keyBytes, Object value, byte[] valueBytes, Cluster cluster) {
    //这边根据返回值就是分区号, 这边就是固定发送到三号分区
    return 3;
  }

  @Override
  public void close() {

  }
  @Override
  public void configure(Map configs) {

  }

}

import org.apache.kafka.clients.producer.ProducerInterceptor;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;

import java.util.Map;
import java.util.UUID;

public class MessageInterceptor implements ProducerInterceptor {

  @Override
  public void configure(Map configs) {
    System.out.println("这是MessageInterceptor的configure方法");
  }

  /**
   * 这个是消息发送之前进行处理
   *
   * @param record
   * @return
   */
  @Override
  public ProducerRecord onSend(ProducerRecord record) {
    // 创建一个新的record，把uuid入消息体的最前部
    System.out.println("为消息添加uuid");
    return new ProducerRecord(record.topic(), record.partition(), record.timestamp(), record.key(),
        UUID.randomUUID().toString().replace("-", "") + "," + record.value());
  }

  /**
   * 这个是生产者回调函数调用之前处理
   * @param metadata
   * @param exception
   */
  @Override
  public void onAcknowledgement(RecordMetadata metadata, Exception exception) {
    System.out.println("MessageInterceptor拦截器的onAcknowledgement方法");
  }

  @Override
  public void close() {
    System.out.println("MessageInterceptor close 方法");
  }
}

import java.util.Map;
import org.apache.kafka.clients.producer.ProducerInterceptor;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;

public class CounterInterceptor implements ProducerInterceptor{
  private int errorCounter = 0;
  private int successCounter = 0;

  @Override
  public void configure(Map configs) {
    System.out.println("这是CounterInterceptor的configure方法");
  }

  @Override
  public ProducerRecord onSend(ProducerRecord record) {
    System.out.println("CounterInterceptor计数过滤器不对消息做任何操作");
    return record;
  }

  @Override
  public void onAcknowledgement(RecordMetadata metadata, Exception exception) {
    // 统计成功和失败的次数
    System.out.println("CounterInterceptor过滤器执行统计失败和成功数量");
    if (exception == null) {
      successCounter++;
    } else {
      errorCounter++;
    }
  }

  @Override
  public void close() {
    // 保存结果
    System.out.println("Successful sent: " + successCounter);
    System.out.println("Failed sent: " + errorCounter);
  }
}

import org.apache.kafka.clients.producer.*;

import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

public class Producer1 {
  public static void main(String[] args) throws Exception {
    Properties props = new Properties();
    // Kafka服务端的主机名和端口号
    props.put("bootstrap.servers", "localhost:9092");
    // 等待所有副本节点的应答
    props.put("acks", "all");
    // 消息发送最大尝试次数
    props.put("retries", 0);
    // 一批消息处理大小
    props.put("batch.size", 16384);
    // 请求延时，可能生产数据太快了
    props.put("linger.ms", 1);
    // 发送缓存区内存大小，数据是先放到生产者的缓冲区
    props.put("buffer.memory", 33554432);
    // key序列化
    props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
    // value序列化
    props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
    // 具体的分区类
    props.put(ProducerConfig.PARTITIONER_CLASS_CONFIG, "kafka.CustomPartitioner");
    //定义拦截器
    List interceptors = new ArrayList<>();
    interceptors.add("kafka.MessageInterceptor");
    interceptors.add("kafka.CounterInterceptor");
    props.put(ProducerConfig.INTERCEPTOR_CLASSES_CONFIG, interceptors);

    Producer producer = new KafkaProducer<>(props);
    for (int i = 0; i < 1; i++) {
      producer.send(new ProducerRecord("test_0515", i + "", "xxx-" + i), new Callback() {
        public void onCompletion(RecordMetadata recordMetadata, Exception e) {
          System.out.println("这是producer回调函数");
        }
      });
    }
    /*System.out.println("现在执行关闭producer");
    producer.close();*/
    producer.close();
  }
}