发布Spring框架5中的JPA存储库连接

Question

我最近开始学习Java，以及Spring 5和Spring。我对创建网络服务相对较新，所以首先我创建了一个在线宠物商店API。我一直在以下github教程中的源代码作为指南：https://github.com/in28minutes/spring-boot-examples/tree/master/spring-boot-2-rest-service-with-swagger

为了部署API，我运行以下命令：

~mvn clean install
~mvn spring-boot:run

它构建成功，没有错误或警告。但是，当我使用spring:run命令时，我会得到以下消息：

未能在项目gs-rest-服务上执行目标org.springframework.boot:spring-boot-maven-plugin:2.0.2.RELEASE:run (默认-cli)：运行过程中出现异常。null: InvocationTargetException:创建名为“petController”的bean时出错:通过字段“petRepository”表示的不满意的依赖关系；嵌套的异常是InvocationTargetException，没有“petstore.pet.PetRepository”类型的限定bean :预期至少有一个bean，它可以作为自动选择。依赖关系注释：{@org.springframework.beans.factory.annotation.Autowired(required=true)} ->帮助1

我搜索了所有地方，但似乎找不到答案。我的代码如下：

pom.xml

<?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>org.springframework</groupId>
    <artifactId>gs-rest-service</artifactId>
    <version>0.1.0</version>

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

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.jayway.jsonpath</groupId>
            <artifactId>json-path</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.1-api</artifactId>
            <version>1.0.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
            <version>1.0.1.Final</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>2.0.7.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.0.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>
    </dependencies>

    <properties>
        <java.version>1.8</java.version>
    </properties>


    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>
</project>

src/main/java/petstore/PetStoreApplication.java

package petstore;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

src/main/java/petstore/pet/Pet.java

package petstore.pet;

import com.sun.javafx.beans.IDProperty;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class Pet {

    @Id
    @GeneratedValue
    private long id;

    private String name;
    private String status;

    public Pet(long id, String name, String status)
    {
        this.id = id;
        this.name = name;
        this.status = status;
    }

    public long getId()
    {
        return this.id;
    }

    public String getName()
    {
        return this.name;
    }

    public String getStatus()
    {
        return this.status;
    }

    public void setId(long id)
    {
        this.id = id;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public void setStatus(String status)
    {
        this.status = status;
    }
}

src/main/java/petstore/pet/PetRepository.java

package petstore.pet;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface PetRepository extends JpaRepository<Pet, Long>
{

}

src/main/java/petstore/PetController.java

package petstore.pet;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;


@RestController
public class PetController
{
    @Autowired
    private PetRepository petRepository;

    @GetMapping("/pets")
    public List<Pet>retrieveAllPets()
    {
        return petRepository.findAll();
    }
}

src/main/java/petstore/pet/PetNotFoundException.java

package petstore.pet;

public class PetNotFoundException extends RuntimeException
{
    public PetNotFoundException(String exception)
    {
        super(exception);
    }
}

我相信我漏掉了一些电线，但我不知道如何解决它，谷歌也没有让我走得太远。为这个冗长的问题道歉。任何帮助都是非常感谢的。

Answer 1

为了使应用程序工作，您应该只包含以下依赖项。此外，我还添加了h2数据库依赖项，因为您可能需要一个才能使应用程序工作。请随意对您使用的数据库进行相应更改。

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
     <dependency>
        <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>           
    <dependency>
        <groupId>org.springframework.data</groupId>
        <artifactId>spring-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
    </dependency>
</dependencies>

Answer 2

您必须添加@EnableJpaRepositories(basePackages =.)在Spring配置中，因为Spring不知道搜索哪些包来查找您的PetRepository

Answer 3

可以尝试添加以下依赖项。

 <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
  </dependency>

此外，不需要版本，因为Spring引导具有此自动配置属性，它将自动获取每个依赖项的可行版本。

如果我们“手动”管理我们的依赖项，我们需要指定所有依赖项的版本号。