Springboot + Kafka 入门实例 入门dem

版本说明

• springboot版本：2.3.3.RELEASE
• kakfa服务端版本：kafka_2.12-2.6.0.tgz
• zookeeper服务端版本：apache-zookeeper-3.6.1-bin.tar.gz

实例搭建前提条件

1，搭建好zookeeper服务，本实例zookeeper使用单机伪集群模式，

192.168.1.126:2181, 192.168.1.126:2182, 192.168.1.126:2183

2，搭建好kafka服务，本实例kafka使用单机伪集群模式，

192.168.1.126:9092, 192.168.1.126:9093, 192.168.1.126:9094

1. 导入相关依赖

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.3.3.RELEASE
         
    

    com.example
    springboot-kafka-demo
    1.0-SNAPSHOT
    springboot-kafka-demo
    springboot-kafka-demo

    
        1.8
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        

        
            org.springframework.kafka
            spring-kafka
        

        
            org.projectlombok
            lombok
            true
        

        
            com.alibaba
            fastjson
            1.2.54
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

2. yml配置

server:
  port: 8080
  servlet:
    context-path: /
  tomcat:
    uri-encoding: UTF-8

spring:
  kafka:
    #本地虚拟机kafka伪集群
    bootstrap-servers: 192.168.1.126:9092,192.168.1.126:9093,192.168.1.126:9094
    producer:
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
      batch-size: 65536
      buffer-memory: 524288
      #自定义的topic
      myTopic1: testTopic1
      myTopic2: testTopic2
    consumer:
      group-id: default-group   #默认组id  后面会配置多个消费者组
      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      auto-offset-reset: latest
      enable-auto-commit: false   #关闭自动提交 改由spring-kafka提交
      auto-commit-interval: 100
      max-poll-records: 20      #批量消费 一次接收的最大数量

3. 部分代码

消息实体类

package com.example.demo.entity;

import java.util.Date;
import lombok.Data;
import lombok.ToString;

@Data
@ToString
public class Message {
    private Long id;
    private String msg;
    private Date sendTime;

}

kafka配置类

package com.example.demo.config;

import lombok.Data;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

/**
 * kafka配置类
 */
@Data
@Configuration
public class KafkaConfiguration {
    /**
     * kafaka集群列表
     */
    @Value("${spring.kafka.bootstrap-servers}")
    private String bootstrapServers;
 
    /**
     * kafaka消费group列表
     */
    @Value("${spring.kafka.consumer.group-id}")
    private String defaultGroupId;
    
    /**
     * 消费开始位置
     */
    @Value("${spring.kafka.consumer.auto-offset-reset}")
    private String autoOffsetReset;
 
    /**
     * 是否自动提交
     */
    @Value("${spring.kafka.consumer.enable-auto-commit}")
    private String enableAutoCommit;
 
    /**
     * #如果'enable.auto.commit'为true，则消费者偏移自动提交给Kafka的频率（以毫秒为单位），默认值为5000。
     */
    @Value("${spring.kafka.consumer.auto-commit-interval}")
    private String autoCommitInterval;
 
    /**
     * 一次调用poll()操作时返回的最大记录数，默认值为500
     */
    @Value("${spring.kafka.consumer.max-poll-records}")
    private String maxPollRecords;

    /**
     * 自定义的topic1
     */
    @Value("${spring.kafka.producer.myTopic1}")
    private String myTopic1;

    /**
     * 自定义的topic2
     */
    @Value("${spring.kafka.producer.myTopic2}")
    private String myTopic2;
 
}

消费者监听类

package com.example.demo.consumer;

import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;

/**
 * 消费者1（监听topic1队列）
 */
@Component
public class ConsumerListener1 {

    @KafkaListener(topics = "${spring.kafka.producer.myTopic1}")
    public void listen(ConsumerRecord record) {
        System.out.println(record);
        String value = record.value();
        System.out.println("消费者1接收到消息：" + value);
    }
}

测试类

package com.example.demo.controller;

import com.alibaba.fastjson.JSON;
import com.example.demo.config.KafkaConfiguration;
import com.example.demo.entity.Message;
import com.example.demo.service.KafkaService;
import com.example.demo.util.UUID;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Date;

@Slf4j
@RestController
@RequestMapping("/kafka")
public class KafkaController {
    @Autowired
    private KafkaService kafkaService;

    @Autowired
    private KafkaConfiguration kafkaConfiguration;

    /**
     * 发送文本消息
     * @param msg
     * @return
     */
    @GetMapping("/send/{msg}")
    public String send(@PathVariable String msg) {
        kafkaService.send(kafkaConfiguration.getMyTopic1(), msg);
        return "生产者发送消息给topic1："+msg;
    }

    /**
     * 发送JSON数据
     * @return
     */
    @GetMapping("/send2")
    public String send2() {
        Message message = new Message();
        message.setId(System.currentTimeMillis());
        message.setMsg("生产者发送消息到topic1: " + UUID.getUUID32());
        message.setSendTime(new Date());

        String value = JSON.toJSONString(message);
        log.info("生产者发送消息到topic1 message = {}", value);

        kafkaService.send(kafkaConfiguration.getMyTopic1(),value);
        return value;
    }

    /**
     * 发送JSON数据
     * @return
     */
    @GetMapping("/send3")
    public String send3() {
        Message message = new Message();
        message.setId(System.currentTimeMillis());
        message.setMsg("生产者发送消息到topic2: " + UUID.getUUID32());
        message.setSendTime(new Date());

        String value = JSON.toJSONString(message);
        log.info("生产者发送消息到topic2 message = {}", value);

        kafkaService.send(kafkaConfiguration.getMyTopic2(),value);
        return value;
    }

}

4. 实例运行结果