1、生产者拦截器

1.1、创建生产者拦截器

package com.atguigu.kafka.interceptor;
import org.apache.kafka.clients.producer.ProducerInterceptor;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;
import org.springframework.stereotype.Component;
import java.util.Map;
//拦截器必须手动注册给kafka生产者（KafkaTemplate）
@Component
public class MyKafkaInterceptor implements ProducerInterceptor<String,String> {
    //kafka生产者发送消息前执行：拦截发送的消息预处理
    @Override
    public ProducerRecord<String, String> onSend(ProducerRecord<String, String> producerRecord) {
        System.out.println("生产者即将发送消息：topic = "+ producerRecord.topic()
        +"，partition:"+producerRecord.partition()
        +"，key = "+producerRecord.key()
        +"，value = "+producerRecord.value());
        return null;
    }

    //kafka broker 给出应答后执行
    @Override
    public void onAcknowledgement(RecordMetadata recordMetadata, Exception e) {
        //exception为空表示消息发送成功
        if(e == null){
            System.out.println("消息发送成功：topic = "+ recordMetadata.topic()
                    +"，partition:"+recordMetadata.partition()
                    +"，offset="+recordMetadata.offset()
            +"，timestamp="+recordMetadata.timestamp());
        }
    }

    @Override
    public void close() {

    }

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

    }
}

1.2、KafkaTemplate配置生产者拦截器

package com.atguigu.kafka.producer;

import com.atguigu.kafka.interceptor.MyKafkaInterceptor;
import jakarta.annotation.PostConstruct;
import jakarta.annotation.Resource;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.kafka.core.KafkaTemplate;
import java.io.IOException;

@SpringBootTest
class KafkaProducerApplicationTests {

    //装配kafka模板类： springboot启动时会自动根据配置文初始化kafka模板类对象注入到容器中
    @Resource
    KafkaTemplate kafkaTemplate;

    @Resource
    MyKafkaInterceptor myKafkaInterceptor;

    @PostConstruct
    public void init() {
        kafkaTemplate.setProducerInterceptor(myKafkaInterceptor);
    }
    @Test
    void contextLoads() throws IOException {
        kafkaTemplate.send("my_topic1", "spring-kafka-生产者拦截器");

        //回调是等kafka，ack以后才执行，需要阻塞
        System.in.read();
    }
}

1.3、使用Java代码创建主题分区副本

package com.atguigu.kafka.config;
import org.apache.kafka.clients.admin.NewTopic;
import org.springframework.context.annotation.Bean;
import org.springframework.kafka.config.TopicBuilder;
import org.springframework.stereotype.Component;
@Component
public class KafkaTopicConfig {
    @Bean
    public NewTopic myTopic1() {
        //相同名称的主题 只会创建一次，后面创建的主题名称相同配置不同可以做增量更新（分区、副本数）
        return TopicBuilder.name("my_topic1")//主题名称
                .partitions(3)//主题分区
                .replicas(3)//主题分区副本数
                .build();//创建
    }
}

1.4、application.yml配置----v1版

server:
  port: 8110

# v1
spring:
  kafka:
    bootstrap-servers: 192.168.74.148:9095,192.168.74.148:9096,192.168.74.148:9097
    producer: # producer 生产者
      retries: 0 # 重试次数 0表示不重试
      acks: -1 # 应答级别:多少个分区副本备份完成时向生产者发送ack确认(可选0、1、-1/all)
      batch-size: 16384 # 批次大小 单位byte
      buffer-memory: 33554432 # 生产者缓冲区大小 单位byte
      key-serializer: org.apache.kafka.common.serialization.StringSerializer # key的序列化器
      value-serializer: org.apache.kafka.common.serialization.StringSerializer # value的序列化器

1.5、屏蔽 kafka debug 日志 logback.xml

<configuration>　　　　　　
    <!-- 如果觉得idea控制台日志太多，src\main\resources目录下新建logback.xml
屏蔽kafka debug -->
    <logger name="org.apache.kafka.clients" level="debug" />
</configuration>

1.6、引入spring-kafka依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <!-- Generated by https://start.springboot.io -->
    <!-- 优质的 spring/boot/data/security/cloud 框架中文文档尽在 => https://springdoc.cn -->
    <groupId>com.atguigu.kafka</groupId>
    <artifactId>kafka-producer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>kafka-producer</name>
    <description>kafka-producer</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>


        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

1.7、控制台日志

生产者即将发送消息：topic = my_topic1，partition:null，key = null，value = spring-kafka-生产者拦截器
消息发送成功：topic = my_topic1，partition:0，offset=0，timestamp=1717490776329

[
  [
    {
      "partition": 0,
      "offset": 0,
      "msg": "spring-kafka-生产者拦截器",
      "timespan": 1717490776329,
      "date": "2024-06-04 08:46:16"
    }
  ]
]