kafka producers and consumers

package com.yy.fastcustom;

import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;

import java.util.Arrays;
import java.util.Properties;

/**
 * Created by zzq on 2019/6/13/013.
 */
public class KafkaTest implements Runnable {
    public void read(String clientId) {
        producer.send(new ProducerRecord<String, String>("read", clientId));
        System.out.println("=========" + clientId);
        System.out.println();
    }

    public volatile Producer<String, String> producer;

    public volatile KafkaConsumer<String, String> customer;

    // consumption method 
    @Override
     public  void RUN () {
        customer.subscribe(Arrays.asList("read"));
        for (; ; ) {
            ConsumerRecords<String, String> records = customer.poll(100);
            for (ConsumerRecord<String, String> record : records) {
                System.out.printf ( "offset =% d,% S value =" , record.offset (), record.value ());
                System.out.println();
            }
        }
    }

    public Producer<String, String> producer() {
        Properties properties = new Properties();
        properties.put ( "bootstrap.servers", "10.10.210.123:9092" );
         // producers need server after receiving the data, to send a signal to acknowledge receipt
         // 0 Producer does not need to wait for any acknowledgment message throughput the highest amount
         // 1 means that at least wait leader has successfully write data to a local log, does not mean all that has been written follower
         // All means leader needs to wait for all backups are successfully written to the log 
        properties.put ( "ACKs", "0" );
        properties.put ( "retries", 0); // number of retries 
        properties.put ( "batch.size", 16384); // Producer attempt to record a message batch processing. The purpose is to reduce the number of requests, improve performance between client and server. This configuration is the number of bytes of a control message batch processing. If set to 0, disables batch. If set too large, will take up memory space. 
        Properties.put ( "linger.ms", 1 );
        properties.put("buffer.memory", 33554432);// 缓存大小
        properties.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        properties.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        Producer<String, String> producer = null;
        producer = new KafkaProducer<String, String>(properties);
        return producer;
    }

    public KafkaConsumer<String, String> customer() {
        Properties properties = new Properties();
        properties.put("bootstrap.servers", "10.10.210.123:9092");
        properties.put("group.id", "read");
        properties.put ( "enable.auto.commit", "to true"); // offset Consumer received message will be automatically synchronized to ZooKeeper 
        properties.put ( "auto.commit.interval.ms", "1000" ); // consumer commit frequency offset to the zookeeper, in milliseconds 
        properties.put ( "auto.offset.reset", "Earliest"); // if zk no offset from the initial position on the record start spending 
        properties.put ( "session.timeout.ms", "30000" );
        properties.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        properties.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
        KafkaConsumer<String, String> kafkaConsumer = new KafkaConsumer<>(properties);
        return kafkaConsumer;
    }
}

 <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-clients</artifactId>
            <version>0.10.2.1</version>
        </dependency>