31.SpringBoot整合Kafka

介绍

Kafka在实时流处理中，经常会和Flink结合一起使用，Flink接收来自Kafka的流数据进行处理，那么源源不断的Kafka数据怎么来的呢？如果是生产环境会有大量真实数据过来，但是测试环境我们要怎么模拟生产环境生产大量实时数据呢？

下面我们来整合SpringBoot来模拟生产环境产生大量数据的情况

业务

我们模拟每隔一秒向Kafka的主题中发送一条消息，使用定时任务实现

POM

新建一个SpringBoot项目，添加下面的依赖

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

    <!--fastjson-->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.69</version>
    </dependency>

YML

配置Kafka生产者消费者和服务地址以及端口

spring:
  kafka:
    bootstrap-servers: 121.5.160.142:9092
    producer:
      retries: 0
      acks: 1
      batch-size: 16384
      buffer-memory: 33554432
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
    consumer:
      group-id: consumer-group
      enable-auto-commit: true
      auto-commit-interval: 100
      auto-offset-reset: latest
      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value-deserializer: org.apache.kafka.common.serialization.StringDeserializer

server:
  port: 80

Kafka Producer

声明Kafka生产者发送消息，这里我们将User实体序列化成JSONString作为消息，通过@Scheduled(fixedDelay = 1000 * 1)注解每隔一秒发送一个消息

package com.example.kafka.controller;

import com.alibaba.fastjson.JSON;
import com.example.kafka.dto.User;
import com.example.kafka.util.DateUtil;
import com.example.kafka.util.NumberUtil;
import com.example.kafka.util.UUIDUtil;
import com.example.kafka.util.id.IdGenerator;
import lombok.extern.slf4j.Slf4j;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.text.ParseException;

@RestController
@Slf4j
public class KafkaProducer {
    @Resource
    private KafkaTemplate<String, Object> kafkaTemplate;

    @Scheduled(fixedDelay = 1000 * 1)
    public void sendMessage() throws ParseException {
    	//声明实体
        User user = new User();
        user.setId(IdGenerator.nextCommonId());
        user.setUsername(UUIDUtil.nextUUID().substring(0,10));
        user.setPassword(UUIDUtil.nextUUID().substring(0,10));
        user.setAddress(UUIDUtil.nextUUID().substring(0,10));
        user.setEmail(UUIDUtil.nextUUID().substring(0,10));
        user.setProfile(UUIDUtil.nextUUID().substring(0,10));
        user.setBirthday(DateUtil.randomDate());
        user.setRegisterDay(DateUtil.randomDate());
        user.setLoginDay(DateUtil.randomDate());
        user.setStatus(NumberUtil.getStatusInt());
        user.setAccount(NumberUtil.accountDecimal());
        user.setBalance(NumberUtil.balanceDecimal());
        user.setAge(NumberUtil.getAgeInt());
        user.setSex(NumberUtil.getSexInt());
        user.setAvatar(UUIDUtil.nextUUID().substring(0,10));
        user.setLevel(NumberUtil.getLevelInt());
        
        //发送消息
        kafkaTemplate.send("kafka", JSON.toJSONString(user));
        log.info("kafka producer send message : {}", JSON.toJSONString(user));
        
    }
}

Kafka Consumer

Kafka消费者，从kafka主题消费消息

package com.example.kafka.controller;

import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;

import java.util.Optional;

@Component
@Slf4j
public class KafkaConsumer {

    //不指定group，默认取yml里配置的
    @KafkaListener(topics = {"kafka"})
    public void onMessage1(ConsumerRecord<?, ?> consumerRecord) {
        Optional<?> optional = Optional.ofNullable(consumerRecord.value());
        if (optional.isPresent()) {
            Object msg = optional.get();
            log.info("kafka consumer receive message : {}", msg);
        }
    }

}

启动类

注意添加@EnableScheduling注解启动定时任务功能

package com.example.kafka;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@EnableScheduling
public class KafkaApplication {

    public static void main(String[] args) {
        SpringApplication.run(KafkaApplication.class, args);
    }

}

效果

生产者定时每隔一秒发送任务，消费者消费任务，都会在日志中打印出来，如下

来源：https://blog.csdn.net/weixin_41405524/article/details/125762379