springboot整合kafka

安装了kafak2.3.0的前提下，并且已经打开服务。安装教程：https://mp.csdn.net/postedit/102837603

pom引入依赖：

       
            org.springframework.kafka
            spring-kafka
            2.3.0.RELEASE
        

pom文件如下：

    4.0.0

    com.freshbin
    spring-boot-01
    1.0-SNAPSHOT

    
    
        org.springframework.boot
        spring-boot-starter-parent
        2.2.0.RELEASE
    

    
    
    	
        
		    org.springframework.kafka
		    spring-kafka
		    2.3.0.RELEASE
		
		
        
			org.projectlombok
			lombok
		
		
		
			com.alibaba
			fastjson
			1.2.49
		
		
        
            org.springframework.boot
            spring-boot-starter-web
        

		
            commons-beanutils
            commons-beanutils
            1.8.0
        
        
            commons-collections
            commons-collections
            3.2.1
        
        
            commons-lang
            commons-lang
            2.4
        
        
            commons-logging
            commons-logging
            1.1.1
        
        
            net.sf.ezmorph
            ezmorph
            1.0.6
        
        
            net.sf.json-lib
            json-lib
            jdk15
            2.2.3
        
        
        
		
			org.apache.poi
			poi
			4.0.1
		
		
		
			org.apache.poi
			poi-ooxml
			4.0.1
		
		
		
			org.apache.poi
			poi-scratchpad
			4.0.1
		
		
		
			org.apache.poi
			poi-excelant
			4.0.1
		
    

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

    
    
    
        
            spring-snapshots
            https://repo.spring.io/snapshot
            true
        
        
            spring-milestones
            https://repo.spring.io/milestone
        
    
    
        
            spring-snapshots
            https://repo.spring.io/snapshot
        
        
            spring-milestones
            https://repo.spring.io/milestone
        
    

不知道为什么，pom文件会有个红×，但是不影响项目运行。

发送消息的数据类UserLog：

package com.freshbin.example01.kafka.bean;

import lombok.Data;
import lombok.experimental.Accessors;

/**
 * @Author freshbin
 * @Description 定义用户发送的日志数据
 * @Date 2019-10-31 15:42:14
 */

@Data
@Accessors(chain = true)
public class UserLog {
    private String username;
    private String userid;
    private String state;
}

生产者类UserLogProducer：

package com.freshbin.example01.kafka.producer;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson.JSON;
import com.freshbin.example01.kafka.bean.UserLog;
 
/**
 * @Author freshbin
 * @Description
 * @Date 2019-10-31 15:46:16
 */
@Component
public class UserLogProducer {
    @Autowired
    private KafkaTemplate kafkaTemplate;
 
    /**
     * 发送数据
     * @param userid
     */
    public void sendLog(String userid){
        UserLog userLog = new UserLog();
        userLog.setUsername("freshbin").setUserid(userid).setState("0");
        System.out.println("发送用户日志数据:" + userLog);
        kafkaTemplate.send("user-log", JSON.toJSONString(userLog));
    }
}

消费者类UserLogConsumer：

package com.freshbin.example01.kafka.comsumer;

import java.util.Optional;

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

import lombok.extern.slf4j.Slf4j;

/**
 * @Author freshbin
 * @Description
 * @Date 2019-10-31 15:49:23
 */
@Component
@Slf4j
public class UserLogConsumer {
	@KafkaListener(topics = { "user-log" })
	public void consumer(ConsumerRecord consumerRecord) {
		// 判断是否为null
		Optional kafkaMessage = Optional.ofNullable(consumerRecord.value());
		log.info(">>>>>>>>>> record =" + kafkaMessage);
		if (kafkaMessage.isPresent()) {
			// 得到Optional实例中的值
			Object message = kafkaMessage.get();
			System.out.println("消费消息:" + message);
		}
	}
}

启动主类KafkaApplication，直接在init方法中发送消息：

package com.freshbin.example01.kafka;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

import com.freshbin.example01.kafka.producer.UserLogProducer;

import javax.annotation.PostConstruct;
 
/**
 * @Author freshbin
 * @Description
 * @Date 2019-10-31 15:46:07
 */
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class KafkaApplication {
 
    @Autowired
    private UserLogProducer kafkaSender;
    
    @PostConstruct
    public void init(){
        for (int i = 0; i < 10; i++) {
            //调用消息发送类中的消息发送方法
            kafkaSender.sendLog(String.valueOf(i));
            System.out.println("已经发送了一个消息：" + i);
        }
    }
 
    public static void main(String[] args) {
        SpringApplication.run(KafkaApplication.class, args);
    }
}

application.properties文件配置如下：

spring.application.name=kafka-user
server.port=8080
#============== kafka ===================
# 指定kafka 代理地址，可以多个
spring.kafka.bootstrap-servers=localhost:9092
 
#=============== provider  =======================
spring.kafka.producer.retries=0
# 每次批量发送消息的数量
spring.kafka.producer.batch-size=16384
spring.kafka.producer.buffer-memory=33554432
 
# 指定消息key和消息体的编解码方式
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.apache.kafka.common.serialization.StringSerializer
 
#=============== consumer  =======================
# 指定默认消费者group id
spring.kafka.consumer.group-id=user-log-group
 
spring.kafka.consumer.auto-offset-reset=earliest
spring.kafka.consumer.enable-auto-commit=true
spring.kafka.consumer.auto-commit-interval=100
 
# 指定消息key和消息体的编解码方式
spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.consumer.value-deserializer=org.apache.kafka.common.serialization.StringDeserializer

启动之后控制台就会打印相应的信息：

 

同时zk和kafka的dos窗口也会打印一些东西，不过没有仔细看打印了什么，反正也看不懂的。

虽然springboot整合了kafka，感觉demo还挺简单的，但是还不知道如何应用到真实的项目中。