异步发送数据

package com.shf.kafka.producer;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.serialization.StringSerializer;
import java.util.Properties;
/**
 * 异步发送
 */
public class CustomProducer {
    public static void main(String[] args) {
        // 1. 创建 kafka 生产者的配置对象
        Properties properties = new Properties();

        // 2. 给 kafka 配置对象添加配置信息：bootstrap.servers
        properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.1.4:9092");

        properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);

        // 3. 创建 kafka 生产者对象
        KafkaProducer<String, String> kafkaProducer = new KafkaProducer<String, String>(properties);

        // 4. 调用 send 方法,发送消息
        for (int i = 0; i < 5; i++) {
            kafkaProducer.send(new ProducerRecord<>("first", "atguigu " + i));
        }
        // 5. 关闭资源
        kafkaProducer.close();
    }
}

异步回调

import org.apache.kafka.clients.producer.*;
import org.apache.kafka.common.serialization.StringSerializer;

import java.util.Properties;

/**
 * 返回消息的信息
 */
public class CustomProducerCallback {
    public static void main(String[] args) {
        // 1. 创建 kafka 生产者的配置对象
        Properties properties = new Properties();

        // 2. 给 kafka 配置对象添加配置信息：bootstrap.servers
        properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.120.20:9092,192.168.120.20:9093,192.168.120.20:9094");

        properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);

        // 3. 创建 kafka 生产者对象
        KafkaProducer<String, String> kafkaProducer = new KafkaProducer<String, String>(properties);

        // 4. 调用 send 方法,发送消息
        for (int i = 0; i < 5; i++) {
            kafkaProducer.send(new ProducerRecord<>("first", "atguigu " + i), new Callback() {
                @Override
                public void onCompletion(RecordMetadata recordMetadata, Exception e) {
                    if (e == null) {
                        System.out.println("success");
                        System.out.println("主体："+recordMetadata.topic());
                        System.out.println("分区："+recordMetadata.partition());
                    } else {
                        System.out.println("fail");
                    }
                }
            });
        }

        // 5. 关闭资源
        kafkaProducer.close();
    }

}

看原理图，返回参数就是RecordAccumulator中的

同步发送

import lombok.SneakyThrows;
import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.serialization.StringSerializer;

import java.util.Properties;

public class CustomProducerSync {
    @SneakyThrows
    public static void main(String[] args) {
        // 1. 创建 kafka 生产者的配置对象
        Properties properties = new Properties();

        // 2. 给 kafka 配置对象添加配置信息：bootstrap.servers
        properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.120.20:9092,192.168.120.20:9093,192.168.120.20:9094");

        properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);

        // 3. 创建 kafka 生产者对象
        KafkaProducer<String, String> kafkaProducer = new KafkaProducer<String, String>(properties);

        // 4. 调用 send 方法,发送消息
        for (int i = 0; i < 5; i++) {
            kafkaProducer.send(new ProducerRecord<>("first", "atguigu " + i)).get();
        }

        // 5. 关闭资源
        kafkaProducer.close();
    }

}

原理图如下，保证生产者100%发送消息

分区情况

可以通过如果设置了key，那么分区则会通过对key进行取模得出对应的分区，自定义分区

public class MyPartitioner implements Partitioner {

    @Override
    public int partition(String topic, Object key, byte[] keyBytes, Object value, byte[] valueBytes, Cluster cluster) {
        String msgValues = value.toString();

        int partition;

        if (msgValues.contains("shf")) {
            partition = 0;
        } else {
            partition = 1;
        }
        return partition;
    }

    @Override
    public void close() {

    }

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

    }
}

docker 创建kafka

https://www.cnblogs.com/JcHome/p/16475990.html