发送消息+自定义Partitioner

        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-clients</artifactId>
        </dependency>

package com.perfect.kafka;

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

import java.util.Arrays;
import java.util.Map;

public class CustomPartiton implements Partitioner {

    @Override
    public int partition(String s, Object o, byte[] bytes, Object o1, byte[] bytes1, Cluster cluster) {
        System.out.println("s = " + s + ", o = " + o + ", bytes = " + Arrays.toString(bytes) + ", o1 = " + o1 + ", bytes1 = " + Arrays.toString(bytes1) + ", cluster = " + cluster);
        return 0;
    }

    @Override
    public void close() {

    }

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

    }
}

package com.perfect.kafka;

import org.apache.kafka.clients.producer.*;
import org.apache.kafka.common.Cluster;
import org.junit.jupiter.api.Test;

import java.util.*;

public class PartitonerTest {

    @Test
    public void sendmessagetest(){

        Properties props = new Properties();

        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,"localhost:9092");

        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.StringSerializer");

        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,"org.apache.kafka.common.serialization.StringSerializer");

        props.put(ProducerConfig.PARTITIONER_CLASS_CONFIG,"com.perfect.kafka.CustomPartiton");

        KafkaProducer<String,String> p = new KafkaProducer<String, String>(props);

        List<String> list = new ArrayList<>();

        list.add("a");
        list.add("b");
        list.add("c");


        for(int i=0;i<10;i++){
            p.send(new ProducerRecord<>("topic2", list.get(i%3),"message"+i), new Callback() {
                @Override
                public void onCompletion(RecordMetadata recordMetadata, Exception e) {
                    if(e==null){
                        System.out.println(recordMetadata.partition()+"---"+recordMetadata.offset());
                    }
                }
            });
        }

        p.close();

    }
}