kafka拦截器（示例）

1. 拦截内容在内容前加时间戳

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 TimeInterceptor implements ProducerInterceptor<String, String> {

	@Override
	public void configure(Map<String, ?> configs) {

	}

	@Override
	public ProducerRecord<String, String> onSend(ProducerRecord<String, String> record) {
		// 创建一个新的record，把时间戳写入消息体的最前部
		return new ProducerRecord(record.topic(), record.partition(), record.timestamp(), record.key(),
				System.currentTimeMillis() + "," + record.value().toString());
	}

	@Override
	public void onAcknowledgement(RecordMetadata metadata, Exception exception) {

	}

	@Override
	public void close() {

	}
}

2. 拦截内容计数

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<String, String>{
    private int errorCounter = 0;
    private int successCounter = 0;

	@Override
	public void configure(Map<String, ?> configs) {
		
	}

	@Override
	public ProducerRecord<String, String> onSend(ProducerRecord<String, String> record) {
		 return record;
	}

	@Override
	public void onAcknowledgement(RecordMetadata metadata, Exception exception) {
		// 统计成功和失败的次数
        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);
	}
}

3. 主程序

import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;

public class InterceptorProducer {

	public static void main(String[] args) throws Exception {
		// 1 设置配置信息
		Properties props = new Properties();
		props.put("bootstrap.servers", "hadoop01:9092");
		props.put("acks", "all");
		props.put("retries", 0);
		props.put("batch.size", 16384);
		props.put("linger.ms", 1);
		props.put("buffer.memory", 33554432);
		props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
		props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
		
		// 2 构建拦截链
		List<String> interceptors = new ArrayList<>();
		interceptors.add("TimeInterceptor"); 	interceptors.add("CounterInterceptor");
		props.put(ProducerConfig.INTERCEPTOR_CLASSES_CONFIG, interceptors);
		 
		String topic = "first";
		Producer<String, String> producer = new KafkaProducer<>(props);
		
		// 3 发送消息
		for (int i = 0; i < 10; i++) {
			
		    ProducerRecord<String, String> record = new ProducerRecord<>(topic, "message" + i);
		    producer.send(record);
		}
		 
		// 4 一定要关闭producer，这样才会调用interceptor的close方法
		producer.close();
	}
}

运行结果
API端

Linux端