Kafka的接口回调 +自定义分区、拦截器

一、接口回调+自定义分区

　　1.接口回调：在使用消费者的send方法时添加Callback回调

producer.send(new ProducerRecord<String, String>("xinnian", "20" + i + "年新年好！"), new Callback() {
    public void onCompletion(RecordMetadata recordMetadata, Exception e) {
        if (recordMetadata!=null){
            System.out.println(recordMetadata.topic()+"-----"+recordMetadata.offset()+"-----"+recordMetadata.partition());
        }
    }
　2.自定义分区：定义类实现Patitioner接口，实现接口的方法：
   设置configure、分区逻辑partition（return 1;）、释放资源close、在生产者的配置过程中添加入分区属性。
　在定义生产者属性时添加分区的属性即可

/**
 * @author: PrincessHug
 * @date: 2019/2/28, 16:24
 * @Blog: https://www.cnblogs.com/HelloBigTable/
 */
public class PartitionDemo implements Partitioner {
    public int partition(String s, Object o, byte[] bytes, Object o1, byte[] bytes1, Cluster cluster) {
        return 1;
    }

    public void close() {

    }

    public void configure(Map<String, ?> map) {

    }
}

public class ProducerDemo {
    public static void main(String[] args) {
        Properties prop = new Properties();

        //参数配置
        //kafka节点的地址
        prop.put("bootstrap.servers", "192.168.126.128:9092");
        //发送消息是否等待应答
        prop.put("acks", "all");
        //配置发送消息失败重试
        prop.put("retries", "0");
        //配置批量处理消息大小
        prop.put("batch.size", "10241");
        //配置批量处理数据延迟
        prop.put("linger.ms","5");
        //配置内存缓冲大小
        prop.put("buffer.memory", "12341235");
        //消息在发送前必须序列化
        prop.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        prop.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        prop.put("partitioner.class", "PartitionDemo");

        KafkaProducer<String, String> producer = new KafkaProducer<String, String>(prop);

        for (int i=10;i<100;i++){
            producer.send(new ProducerRecord<String, String>("xinnian", "20" + i + "年新年好！"), new Callback() {
                public void onCompletion(RecordMetadata recordMetadata, Exception e) {
                    if (recordMetadata!=null){
                        System.out.println(recordMetadata.topic()+"-----"+recordMetadata.offset()+"-----"+recordMetadata.partition());
                    }
                }
            });
        }
        producer.close();
    }
}

　　注意：在自定义分区后，你的消费者会收不到消息，因为消费者默认接收的分区为0。

二、拦截器

　　1）创建生产者类；
 　   2）创建自定义拦截器类实现ProducerInterceptor接口，重写抽象方法；
 　   3）在业务逻辑方法ProducerRecord方法中，修改返回值，
   　　　  return new ProducerRecord<String,String>(
     　　　record.topic(),
     　　　record.partiiton(),
   　　　  record.key(),
    　　　 System.currentTimeMillis() + "-" + record.value() + "-" + record.topic());
  　  4）在生产者类中将自定义拦截器生效
  　　　　 prop.put(ProducerConfig.INTERCEPTOR_CLASSEA_CONFIG,"com.wyh.com.wyh.kafka.interceptor.TimeInterceptor");
  　  5）运行生产者main方法，或者在linux端用shell测试。

/**
 * @author: PrincessHug
 * @date: 2019/2/28, 20:59
 * @Blog: https://www.cnblogs.com/HelloBigTable/
 */
public class TimeInterceptor implements ProducerInterceptor<String, String> {

    //业务逻辑
    public ProducerRecord<String, String> onSend(ProducerRecord<String, String> producerRecord) {
        return new ProducerRecord<String,String>(
                producerRecord.topic(),
                producerRecord.partition(),
                producerRecord.key(),
                System.currentTimeMillis()+"--"+producerRecord.value()
        );
    }

    //发送失败调用
    public void onAcknowledgement(RecordMetadata recordMetadata, Exception e) {

    }

    //释放资源
    public void close() {

    }

    //获取配置信息
    public void configure(Map<String, ?> map) {

    }
}

public class ItctorProducer {
    public static void main(String[] args) {
        //配置生产者属性
        Properties prop = new Properties();
        //kafka节点的地址
        prop.put("bootstrap.servers", "192.168.126.128:9092");
        //发送消息是否等待应答
        prop.put("acks", "all");
        //配置发送消息失败重试
        prop.put("retries", "0");
        //配置批量处理消息大小
        prop.put("batch.size", "1024");
        //配置批量处理数据延迟
        prop.put("linger.ms","5");
        //配置内存缓冲大小
        prop.put("buffer.memory", "12341235");
        //消息在发送前必须序列化
        prop.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        prop.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

        //添加拦截器
        ArrayList<String> inList = new ArrayList<String>();
        inList.add("interceptor.TimeInterceptor");
        prop.put(ProducerConfig.INTERCEPTOR_CLASSES_CONFIG,inList);

        //实例化producer
        KafkaProducer<String, String> producer = new KafkaProducer<String, String>(prop);

        //发送消息
        for (int i=0;i<99;i++){
            producer.send(new ProducerRecord<String, String>("xinnian","You are genius!"+i));
        }

        //释放资源
        producer.close();
        
    }
}