应用程序启动失败 Spring Boot

Question

我有一个使用Spring Boot的框架，其中包含一个控制器 RestController 类，

@RequestMapping("/details")
@RestController
public class DataController {
    private KafkaStreams kafkaStreams;

    public DataController(KafkaStreams kafkaStreams) {
        this.kafkaStreams = kafkaStreams;
    }

    @Autowired
    DataService dataService;

    @RequestMapping(value = "getAllDetails", method = RequestMethod.GET)
    public boolean getAllDetails(KafkaStreams kafkaStreams) {
        return ktableService.getAllDetails(kafkaStreams);
    }
}

在我的服务实现类中，我正在使用这个kafkaStreams对象来查找我的不同服务的详细信息。

现在我将这个框架作为依赖项在我的另一个应用程序中使用，在那里我有一个运行器类。

import org.apache.kafka.streams.KafkaStreams;
@Component
public class PipelineRunner {
    private final StreamsBuilder streamsBuilder;
    private final KafkaProperties kafkaProperties;
    private final SerdesExt serdesExt;

    @Autowired
    public PipelineRunner(StreamsBuilder streamsBuilder, KafkaProperties kafkaProperties, SerdesExt serdesExt) {
        this.streamsBuilder = streamsBuilder;
        this.kafkaProperties = kafkaProperties;
        this.serdesExt = serdesExt;
    }

    @PostConstruct
    public void run() {
        ReflectData.AllowNull.get().addStringable(Utf8.class);
        ReflectData.get().addStringable(Utf8.class);
        DataProcessor processor = new DataProcessor(streamsBuilder, kafkaProperties,
                serdesExt);
        start();
    }

    private void start() {
        KafkaStreams kafkaStreams = new KafkaStreams(streamsBuilder.build(),
                kafkaProperties.getKafkaStreamsProperties(serdesExt));
        System.out.println("----Its is started----");
        DataController controller = new DataController(kafkaStreams);
        kafkaStreams.start();

    }
}

在这个类中，我正在尝试创建 DataController 对象。

所以当我尝试运行应用程序类时，

@SpringBootApplication(scanBasePackages = { "framework package" })
@EnableConfigurationProperties(KafkaProperties.class)
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

我遇到了这个错误：

***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 0 of constructor in frameworkpackage.controllers.DataController required a bean of type 'org.apache.kafka.streams.KafkaStreams' that could not be found.


Action:

Consider defining a bean of type 'org.apache.kafka.streams.KafkaStreams' in your configuration.

我是新手，对Spring Boot不太熟悉，可能会做错什么。如果需要更多信息，我可以提供。

更新

我的pom文件，

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.RELEASE</version>
    </parent>

    <properties>
        <confluent.version>4.1.0</confluent.version>
        <kafka.version>1.1.0</kafka.version>
        <lombok.version>1.18.0</lombok.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>io.confluent</groupId>
            <artifactId>kafka-avro-serializer</artifactId>
            <version>${confluent.version}</version>
        </dependency>
        <dependency>
            <groupId>io.confluent</groupId>
            <artifactId>kafka-streams-avro-serde</artifactId>
            <version>${confluent.version}</version>
        </dependency>

        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-streams</artifactId>
            <version>${kafka.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.kafka</groupId>
            <artifactId>kafka-clients</artifactId>
            <version>${kafka.version}</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-avro</artifactId>
            <version>2.8.5</version>
        </dependency>

    </dependencies>

- Justin

---

你是否添加了Kafka Streams的spring boot starter依赖？更新问题时附上pom.xml或build.gradle会更有见地。 - Branislav Lazic

@BranislavLazic 添加了pom文件。 - Justin

我不知道如何在Spring Boot中配置Kafka，但我认为你的private KafkaStreams kafkaStreams;应该在构造函数中自动装配或注入（根据你的日志）。 - Mickael

@MickaëlB 是的。我以为Spring Boot会自动配置它。但是没有。看起来他必须手动定义“KafkaStreams” bean。 - Branislav Lazic

@MickaëlB 我尝试在 private KafkaStreams kafkaStreams; 中添加 @Autowired，但仍然遇到相同的问题。 - Justin

@Justin 如果你想要自动装配 KafkaStreams，你必须在某个地方声明这个 bean。我认为应该是你的 kafkaStreams = new KafkaStreams(streamsBuilder.build(), kafkaProperties.getKafkaStreamsProperties(serdesExt)); 或类似的代码。 - Mickael

Answer 1

问题在于你试图在DataController类中使用一个名为的bean，但是在Spring上下文中没有这个名字的bean。你需要手动创建它，这样你就可以稍后进行自动装配。

对于你的情况，我建议像这样更新PipelineRunner.java:

import javax.annotation.PostConstruct;
import org.apache.kafka.streams.KafkaStreams;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.kafka.KafkaProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

@Component
public class PipelineRunner
{
    private final StreamsBuilder streamsBuilder;
    private final KafkaProperties kafkaProperties;
    private final SerdesExt serdesExt;


    @Autowired
    public PipelineRunner(StreamsBuilder streamsBuilder, KafkaProperties kafkaProperties, SerdesExt serdesExt)
    {
        this.streamsBuilder = streamsBuilder;
        this.kafkaProperties = kafkaProperties;
        this.serdesExt = serdesExt;
    }


    @PostConstruct
    public void run()
    {
        ReflectData.AllowNull.get().addStringable(Utf8.class);
        ReflectData.get().addStringable(Utf8.class);
        DataProcessor processor = new DataProcessor(streamsBuilder, kafkaProperties,
            serdesExt);
        start();
    }


    @Bean
    KafkaStreams kafkaStreams()
    {
        KafkaStreams kafkaStreams = new KafkaStreams(
            streamsBuilder.build(),
            kafkaProperties.getKafkaStreamsProperties(serdesExt));
        System.out.println("----Its is started----");
        kafkaStreams.start();
        return kafkaStreams;
    }
}

你不需要自己创建DataController的实例，这将由Spring自动完成。

关于Spring对bean的处理方式的更多信息，请参见这里。

- Pavel Gordon