Spring Boot 3 + Kafka 实战指南

------麻辣火锅版 🍲

一、项目层级

像火锅店的分工：点单员、传菜员、食客清清楚楚。

kafka/
├── pom.xml                 # 根 POM（BOM对齐）
├── provider/               # 点单：生产者
│   ├── pom.xml             # 子模块 POM
│   └── src/main/java/org/example/provider/
│       ├── ProviderApplication.java
│       ├── conf/KafkaTopicsConfig.java
│       ├── controller/ProviderController.java
│       └── service/KafkaProducerService.java
│   └── src/main/resources/application.yaml
└── consumer/               # 上桌：消费者
    ├── pom.xml             # 子模块 POM
    └── src/main/java/org/example/consumer/
        ├── ConsumerApplication.java
        └── listener/KafkaConsumerListener.java
    └── src/main/resources/application.yaml

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二、根 POM（大厨的调料表）

<properties>
  <java.version>17</java.version>
  <spring.boot.version>3.4.3</spring.boot.version>
  <spring.cloud.version>2024.0.2</spring.cloud.version>
</properties>

<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-dependencies</artifactId>
      <version>${spring.boot.version}</version>
      <type>pom</type><scope>import</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-dependencies</artifactId>
      <version>${spring.cloud.version}</version>
      <type>pom</type><scope>import</scope>
    </dependency>
  </dependencies>
</dependencyManagement>

👉 全局版本对齐，避免"锅底和食材不搭"。

---

三、子模块 POM

provider/pom.xml

    <parent>
        <groupId>org.example</groupId>
        <artifactId>kafka</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>org.example</groupId>
    <artifactId>provider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>provider</name>
    <description>provider</description>
    <packaging>jar</packaging>

    <properties>
        <java.version>17</java.version>
    </properties>

    <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.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </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-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

consumer/pom.xml

    <parent>
        <groupId>org.example</groupId>
        <artifactId>kafka</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>org.example</groupId>
    <artifactId>consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>consumer</name>
    <description>consumer</description>
    <packaging>jar</packaging>

    <properties>
        <java.version>17</java.version>
    </properties>

    <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.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </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-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>2.0.58</version>
        </dependency>
    </dependencies>

Provider（application.yaml - 生产者）

server:
  port: 1003
app:
  kafka:
    topic: demo.topic.v1
    auto-create-topic: true
spring:
  kafka:
    bootstrap-servers: yiqiquhuxi.cn:9092
    producer:
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.springframework.kafka.support.serializer.JsonSerializer
      acks: all

Consumer（application.yaml -消费者）

server:
  port: 1004
app:
  kafka:
    topic: demo.topic.v1
spring:
  kafka:
    bootstrap-servers: yiqiquhuxi.cn:9092
    consumer:
      group-id: demo-group
      auto-offset-reset: earliest
      value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
      properties:
        spring.json.value.default.type: org.example.consumer.kafka.MessagePayload
        spring.json.trusted.packages: "*"

---

四、配置（菜单写清楚）

入口

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

消息模型

public record MessagePayload(String id, String content, long ts) {}

就像菜单：编号、菜名、上桌时间。

Provider：点菜 + 上菜

@Service
public class KafkaProducerService {
  @Autowired private KafkaTemplate<String, MessagePayload> kafka;
  @Value("${app.kafka.topic}") private String topic;

  public void send(String content) {
    kafka.send(topic, new MessagePayload(UUID.randomUUID().toString(), content, System.currentTimeMillis()));
  }
}

@RestController
@RequestMapping("/provider")
public class ProviderController {
  @Autowired private KafkaProducerService producer;
  @GetMapping("/done") public String done() { producer.send("done"); return "done"; }
}

Consumer：吃菜

@Slf4j
@Component
public class KafkaConsumerListener {
  @KafkaListener(topics = "${app.kafka.topic}", groupId = "${spring.kafka.consumer.group-id}")
  public void onMessage(MessagePayload payload) {
    log.info("🍜 收到菜：{} - {}", payload.id(), payload.content());
  }
}

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五、运行流程

1. 点火：Kafka Broker 先启动。
2. 开店：先跑 consumer，再跑 provider。
3. 点单 ：GET http://localhost:1003/provider/done。
4. 吃菜：consumer 日志里出现 🍜 → 成功！

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六、常见坑

• 锅点不着 ：bootstrap-servers 不通，先查网络。
• 没菜 ：topic 不存在？开 auto-create-topic。
• 吃不到 ：改 group-id 或加 auto-offset-reset=earliest。

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七、总结

Spring Boot + Kafka 的套路：

👉 Provider 点单，Kafka 传菜，Consumer 开吃。

就像火锅：食材扔进去，涮一涮，人人都能分到一口热乎的。🔥