springboot整合kafka实现消息推送

前言

本篇文章主要介绍的是springboot整合kafka。

安装kafka

1.使用docker安装kafka，移步 https://www.jianshu.com/p/89b19f5b28ec

创建工程

1.创建一个名为springboot-kafka的pom项目作为父工程，将main和resource文件夹都删除，pom文件添加配置

<?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>

    <groupId>com.lxg</groupId>
    <artifactId>springboot-kafka</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

    <name>springboot-kafka</name>
    <modules>
        <module>springboot-kafka-common</module>
        <module>springboot-kafka-consumer</module>
        <module>springboot-kafka-producer</module>
    </modules>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.67</version>
        </dependency>
    </dependencies>

</project>

3.创建公共服务模块

创建一个名为springboot-kafka-common的微服务，打包方式为jar，存放一些公共配置和公共类，如util等
1.配置pom文件

<?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">
    <parent>
        <groupId>com.lxg</groupId>
        <artifactId>springboot-kafka</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>springboot-kafka-common</artifactId>
</project>

pom文件中以父工程作为父依赖，就不需要额外引入依赖了
2.新建一个user实体类

@Data
public class User implements Serializable {
    /**
     * id
     */
    private Integer id;

    /**
     * 用户名字
     */
    private String username;

    /**
     * 密码
     */
    private String password;
}

3.创建application-common.yml配置文件，主要添加kafka的公共配置

spring:
  kafka:
    #kafka配置
    bootstrap-servers: 192.168.56.102:9092
    producer:
      retries: 0
      # 每次批量发送消息的数量
      batch-size: 16384
      buffer-memory: 33554432
      # 指定消息key和消息体的编解码方式
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.apache.kafka.common.serialization.StringSerializer
    consumer:
      # 指定默认消费者group id
      group-id: test-consumer-group
      auto-offset-reset: earliest
      enable-auto-commit: true
      auto-commit-interval: 5000
      # 指定消息key和消息体的编解码方式
      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
    #自己定义的主题名称,在微服务中使用Value注解注入调用，如果kafka中没有该主题，则会自动创建
    topic:
      userTopic: userInfo

4.创建消息生产者，即创建一个名为springboot-kafka-producer的普通springboot项目

1.pom文件配置

<?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">

    <groupId>com.lxg</groupId>
    <artifactId>springboot-kafka-producer</artifactId>
    <version>1.0-SNAPSHOT</version>

    <modelVersion>4.0.0</modelVersion>

    <dependencies>
        <dependency>
            <groupId>com.lxg</groupId>
            <artifactId>springboot-kafka-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>

</project>

2.application.yml配置文件，配置端口，设置微服务名称，引入公共服务模块中的application-common.yml

server:
  port: 8081
spring:
  application:
    name: kafka-producer
  profiles:
    active: common

3.controller层
创建UserController

@Slf4j
@Controller
@RequestMapping("/api/user")
public class UserController {
    @Autowired
    private UserService userService;

    @ResponseBody
    @GetMapping("/getUser")
    public void getUser() {
        userService.sendUserMsg();
        log.info("getUser");
    }
}

4.service层
创建UserService

public interface UserService {
    /**
     * 发送用户信息
     *
     * @return
     */
    Boolean sendUserMsg();
}

创建UserServiceImpl

@Slf4j
@Service
public class UserServiceImpl implements UserService {
    @Value("${spring.kafka.topic.userTopic}")
    private String userTopic;

    @Autowired
    KafkaTemplate kafkaTemplate;


    @Override
    public Boolean sendUserMsg() {
        User user = new User();
        user.setId(1);
        user.setUsername("lxg");
        user.setPassword("6767167");
        kafkaTemplate.send(userTopic, JSONObject.toJSONString(user));
        log.info("lxg");
        return Boolean.TRUE;
    }
}

5.创建启动类

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

5.创建消息消费者

1.pom文件

<?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">

    <groupId>com.lxg</groupId>
    <artifactId>springboot-kafka-consumer</artifactId>
    <version>1.0-SNAPSHOT</version>

    <modelVersion>4.0.0</modelVersion>

    <dependencies>
        <dependency>
            <groupId>com.lxg</groupId>
            <artifactId>springboot-kafka-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

2.创建yml配置文件

server:
  port: 8082
spring:
  application:
    name: kafka-consumer
  profiles:
    active: common

3.创建consumer消费者类

@Slf4j
@Component
public class UserConsumer {

    @KafkaListener(topics = {"${spring.kafka.topic.userTopic}"})
    public void userConsumer(String message) {
        log.info("receive msg " + message);
    }
}

4.启动类

@SpringBootApplication
public class ConsumerApplication {

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

测试

启动producer和consumer两个服务模块
访问producer微服务中的接口 http://localhost:8081/api/user/getUser
会发现consumer微服务中的控制台打印了producer中创建并推送过来的的user实体

本文GitHub源码：https://github.com/lixianguo5097/springboot/tree/master/springboot-kafka

CSDN：https://blog.csdn.net/qq_27682773
简书：https://www.jianshu.com/u/e99381e6886e
博客园：https://www.cnblogs.com/lixianguo
个人博客：https://www.lxgblog.com`