<dependencies>

        <dependency>

            <groupId>org.apache.kafka</groupId>

            <artifactId>kafka_2.13</artifactId>

            <version>2.7.0</version>

        </dependency>

    </dependencies>

package com.test.producer;

import org.apache.kafka.clients.producer.KafkaProducer;

import org.apache.kafka.clients.producer.ProducerRecord;

import org.apache.kafka.common.serialization.StringSerializer;

import java.util.Properties;

public class MyProducer {

    public static void main(String[] args) {

        Properties properties = new Properties();

        properties.put("bootstrap.servers", "localhost:9092");

        // ack

        properties.put("acks", "all");

        // 重试次数

        properties.put("retries", 1);

        // 批次大小

        properties.put("batch.size", 16384);

        // 等待时间

        properties.put("linger.ms", 1);

        // 缓冲区大小

        properties.put("buffer.memory", 33554432);

        // 设置数据key和value的序列化处理类

        properties.put("key.serializer", StringSerializer.class);

        properties.put("value.serializer", StringSerializer.class);

        KafkaProducer<String, String> produce = new KafkaProducer<>(properties);

        for (int i=0; i < 2; i++) {

            produce.send(new ProducerRecord<>("test","key-"+i,"value--" + i));

        }

        produce.close();

    }

}

package com.test.consumer;

import org.apache.kafka.clients.consumer.ConsumerConfig;

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.common.serialization.StringDeserializer;

import java.time.Duration;

import java.util.Arrays;

import java.util.Properties;

public class MyConsumer {

    public static void main(String[] args) {

        Properties properties = new Properties();

        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,"localhost:9092");

        // 自动提交

        properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG,true);

        // 提交延时

        properties.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG,"1000");

        // 反序列化

        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);

        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);

        // 消费者组

        properties.put(ConsumerConfig.GROUP_ID_CONFIG,"bigdata");

        // 重置消费者的offset(换组、offset过期)

        properties.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG,"earliest");

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

        // 订阅主题

        consumer.subscribe(Arrays.asList("test"));

        // 获取数据

        while (true){

            ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(100));

            for(ConsumerRecord<String,String> record: records){

                System.out.println("key:" + record.key() + "" + ",value:" +record.value());

            }

        }

    }

}

package com.test.producer;

import org.apache.kafka.clients.producer.*;

import org.apache.kafka.common.serialization.StringSerializer;

import java.util.Properties;

public class CallbackProducer {

    public static void main(String[] args) {

        Properties properties = new Properties();

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

        properties.put("key.serializer", StringSerializer.class);

        properties.put("value.serializer", StringSerializer.class);

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

        for (int i=0; i < 10; i++) {

            producer.send(new ProducerRecord<>("test","1","tt--" + i), (metadata, exception) -> {

                if (exception == null){

                    System.out.println(metadata.partition() + "--" + metadata.offset()) ;

                } else {

                    exception.printStackTrace();

                }

            });

        }

        producer.close();

    }

}