自动连接依赖项的注入失败，无法自动连接字段

Question

这是我的当前设置：ProjectRepo：

package be.italent.repo;

import be.italent.model.Project;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface ProjectRepo extends JpaRepository<Project, Integer> {

}

ProjectService：

package be.italent.services;

import be.italent.model.Project;
import be.italent.repo.ProjectRepo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class ProjectService {

    @Autowired
    private ProjectRepo projectRepo;

    public List<Project> getAllProjects() {
        return projectRepo.findAll();
    }
}

ProjectRestController：

package be.italent.controllers;

import java.util.ArrayList;
import be.italent.services.ProjectService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import be.italent.model.Project;

@RestController
@RequestMapping("/projects")
public class ProjectRestController {

    @Autowired
    private ProjectService projectService;

    @RequestMapping(method = RequestMethod.GET, produces="application/json")
    public ArrayList<Project> getProjects(){
        ArrayList<Project> c = (ArrayList<Project>) projectService.getAllProjects();

        return c;
    }
}

...
<context:component-scan base-package="be.italent"></context:component-scan>
...

<beans
...
jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd">

...

<jpa:repositories base-package="be.italent.repo" entity-manager-factory-ref="emf"/>

Answer 1

当初始化应用程序上下文时出现错误时，Spring经常会给出这些长堆栈跟踪。通常您可以通过查看堆栈跟踪的底部来找出最终原因是什么。

在您的示例中,您会在底部看到以下错误消息：

org.springframework.beans.factory.NosuchBeanDefinitionException：未找到类型为[be.italent.repo.ProjectRepo]的合格bean

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:jpa="http://www.springframework.org/schema/data/jpa"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/data/jpa
           http://www.springframework.org/schema/data/jpa/spring-jpa.xsd">

    <!-- Tell Spring Data JPA where your repository interfaces are -->
    <jpa:repositories base-package="be.italent.repo" />

    <!-- ... -->
</beans>

@Configuration
@EnableJpaRepositories("be.italent.repo")
public class MySpringConfiguration {
    // ...
}