kafka复习：（20）：消费者拦截器的使用

一、定义消费者拦截器（只消费含"sister"的消息）

package com.cisdi.dsp.modules.metaAnalysis.rest;

import org.apache.kafka.clients.consumer.ConsumerInterceptor;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.OffsetAndMetadata;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.TopicPartition;

import java.util.*;

public class MyConsumerInterceptor implements ConsumerInterceptor<String,String> {
    @Override
    public ConsumerRecords<String, String> onConsume(ConsumerRecords<String, String> records) {

        Map<TopicPartition,List<ConsumerRecord<String,String>>> finalResult=new HashMap<>();
        Set<TopicPartition> partitionSet = records.partitions();
        for(TopicPartition topicPartition: partitionSet){
            List<ConsumerRecord<String,String>> partitionRecordList=records.records(topicPartition);
            List<ConsumerRecord<String,String>> newPartitionRecordList=new LinkedList<>();
            for(ConsumerRecord<String,String> record: partitionRecordList){

                if(record.value().contains("sister")){
                    newPartitionRecordList.add(record);
                }

            }
            finalResult.put(topicPartition,newPartitionRecordList);
        }

        return new ConsumerRecords<>(finalResult);
    }

    @Override
    public void onCommit(Map<TopicPartition, OffsetAndMetadata> offsets) {
        offsets.forEach((tp,meta) -> {
            System.out.println("消费者拦截器:"+tp.topic()+":"+meta.offset());
        });
    }

    @Override
    public void close() {

    }

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

    }
}

二、定义消费者，配置消费者拦截器

package com.cisdi.dsp.modules.metaAnalysis.rest;

import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.common.serialization.StringDeserializer;

import java.time.Duration;
import java.util.Arrays;
import java.util.Properties;

public class ConsumerInterceptorTest  {
    public static void main(String[] args) {
        String topic="testTopic2";
        String server="xx.xx.xx.xx:9092";
        Properties properties=new Properties();
        properties.setProperty(ConsumerConfig.GROUP_ID_CONFIG,"consumerGroupTest4");
        properties.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        properties.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
        properties.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,server);
        properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG,true);
        properties.put(ConsumerConfig.INTERCEPTOR_CLASSES_CONFIG,MyConsumerInterceptor.class.getName());

        KafkaConsumer<String,String> myConsumer=new KafkaConsumer<String, String>(properties);

        myConsumer.subscribe(Arrays.asList(topic));
        while(true){
            ConsumerRecords<String,String> records=myConsumer.poll(Duration.ofMillis(2000));
            for(ConsumerRecord consumerRecord: records){
                System.out.println(consumerRecord.value());
            }
            //myConsumer.commitSync();
        }
    }
}