Springboot 2.x集成kafka 2.2.0的示例代码

目录

• 引言
• 基本环境
• 代码编写
• 1、基本引用pom
• 2、基本配置
• 3、实体类
• 4、生产者端
• 5、消费者
• 6、测试
• 效果展示
• 遇到的问题

引言

kafka近几年更新非常快，也可以看出kafka在企业中是用的频率越来越高，在springboot中集成kafka还是比较简单的，但是应该注意使用的版本和kafka中基本配置，这个地方需要信心，防止进入坑中。

版本对应地址：https://spring.io/projects/spring-kafka

基本环境

springboot版本2.1.4

kafka版本2.2.0

jdk 1.8

代码编写

1、基本引用pom

<?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 http://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>2.1.4.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.example</groupId>
	<artifactId>demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>kafkademo</name>
	<description>Demo project for Spring Boot</description>
 
	<properties>
		<java.version>1.8</java.version>
	</properties>
 
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
 
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</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>
			<version>2.2.0.RELEASE</version>
		</dependency>
 
		<dependency>
			<groupId>com.google.code.gson</groupId>
			<artifactId>gson</artifactId>
			<version>2.7</version>
		</dependency>
 
	</dependencies>
 
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
 
</project>

2、基本配置

spring.kafka.bootstrap-servers=2.1.1.1:9092
spring.kafka.consumer.group-id=test-consumer-group
spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.consumer.value-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.apache.kafka.common.serialization.StringSerializer
 
#logging.level.root=debug

3、实体类

package com.example.demo.model;
 
import java.util.Date;
 
public class Messages {
 
    private Long id;
 
    private String msg;
 
    private Date sendTime;
 
    public Long getId() {
        return id;
    }
 
    public void setId(Long id) {
        this.id = id;
    }
 
    public String getMsg() {
        return msg;
    }
 
    public void setMsg(String msg) {
        this.msg = msg;
    }
 
    public Date getSendTime() {
        return sendTime;
    }
 
    public void setSendTime(Date sendTime) {
        this.sendTime = sendTime;
    }
}

4、生产者端

package com.example.demo.service;
 
import com.example.demo.model.Messages;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.support.SendResult;
import org.springframework.stereotype.Service;
import org.springframework.util.concurrent.ListenableFuture;
 
import java.util.Date;
import java.util.UUID;
 
@Service
public class KafkaSender {
 
    @Autowired
    private KafkaTemplate<String, String> kafkaTemplate;
 
    private Gson gson = new GsonBuilder().create();
 
    public void send() {
        Messages message = new Messages();
        message.setId(System.currentTimeMillis());
        message.setMsg("123");
        message.setSendTime(new Date());
        ListenableFuture<SendResult<String, String>> test0 = kafkaTemplate.send("newtopic", gson.toJson(message));
    }
}

5、消费者

package com.example.demo.service;
 
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Service;
 
import java.util.Optional;
 
@Service
public class KafkaReceiver {
 
    @KafkaListener(topics = {"newtopic"})
    public void listen(ConsumerRecord<?, ?> record) {
        Optional<?> kafkaMessage = Optional.ofNullable(record.value());
        if (kafkaMessage.isPresent()) {
            Object message = kafkaMessage.get();
            System.out.println("record =" + record);
            System.out.println("message =" + message);
 
        }
    }
    
}

6、测试

在启动方法中模拟消息生产者，向kafka中发送消息

package com.example.demo;
 
import com.example.demo.service.KafkaSender;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
 
@SpringBootApplication
public class KafkademoApplication {
 
	public static void main(String[] args) {
		ConfigurableApplicationContext context = SpringApplication.run(KafkademoApplication.class, args);
 
		KafkaSender sender = context.getBean(KafkaSender.class);
		for (int i = 0; i <1000; i++) {
			sender.send();
 
			try {
				Thread.sleep(300);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
 
 
	}
 
}

效果展示

命令行直接消费消息

遇到的问题

生产端连接kafka超时

at org.apache.kafka.common.network.NetworkReceive.readFrom(NetworkReceive.java:119)

解决方案：

修改kafka中的server.properties中的下面配置，将原来的默认配置替换成下面ip+端口的形式，重启kafka