Java Spring Boot JPA查询错误-“；无财产''；找到类型为''&引用；例外情况

我目前正在学习一门使用SpringDataJPA的在线SpringBoot课程

我的项目包括两个实体：BDProject和BDUser，它们具有多对一关系。尝试从用户id查找项目时，将显示以下异常

例外情况

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'BDProjectController': Unsatisfied dependency expressed through field 'bdProjectService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'BDProjectService': Unsatisfied dependency expressed through field 'bdProjectRepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'BDProjectRepository': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List com.project.bdproject.BDProjectRepository.findByUserID(java.lang.String)! No property userID found for type BDProject!

我花了数小时试图找出导致此异常的原因，但似乎没有任何东西可以修复它

我的代码：

实体

@Entity
public class BDUser {


@Id
private String userID;
private String bdUsername;
private String bdUserEmail;
private String bdUserPassword;

public BDUser(){
}

public BDUser(String userID, String bdUsername, String bdUserEmail, String bdUserPassword) {
    super();
    this.userID = userID;
    this.bdUsername = bdUsername;
    this.bdUserEmail = bdUserEmail;
    this.bdUserPassword = bdUserPassword;
}
// getters and setters...

@Entity
public class BDProject {

@Id
private String proID;
private String proName;
private String proCodeOwner;
private String proIDs;
@ManyToOne
private BDUser bdUser;

public BDProject() {
}

public BDProject(String proID, String proName, String proCodeOwner, String proIDs, String userID) {
    super();
    this.proID = proID;
    this.proName = proName;
    this.proCodeOwner = proCodeOwner;
    this.proIDs = proIDs;
    this.bdUser = new BDUser(userID, "", "", "");
}
// getters and setters...

控制器

@RestController
public class BDProjectController {

@Autowired
private BDProjectService bdProjectService;

@RequestMapping("/bdusers/{userID}/bdprojects")
public List<BDProject> getAllProjects(@PathVariable String proID){
    return bdProjectService.getAllProjects(proID);
}

@RequestMapping("/bdusers/{userID}/bdprojects/{proID}")
public BDProject getProject(@PathVariable String proID){
    return bdProjectService.getProject(proID);
}

@RequestMapping(method= RequestMethod.POST, value="/bdusers/{userID}/bdprojects")
public void addProject(@RequestBody BDProject bdProject, @PathVariable String userID){
    bdProject.setBdUser(new BDUser(userID, "", "", ""));
    bdProjectService.addProject(bdProject);
}

@RequestMapping(method= RequestMethod.PUT, value="/bdusers/{userID}/bdprojects/{proID}")
public void updateProject(@RequestBody BDProject bdProject, @PathVariable String userID, @PathVariable String proID){
    bdProject.setBdUser(new BDUser(userID, "", "", ""));
    bdProjectService.updateProject(bdProject);
}

@RequestMapping(method= RequestMethod.DELETE, value="/bdusers/{userID}/bdprojects/{proID}")
public void deleteProject(@PathVariable String proID){
    bdProjectService.deleteProject(proID);
}

@RestController
公共类BDProjectController{
@自动连线
私人BDProjectService BDProjectService；
@请求映射（“/bdusers/{userID}/bdprojects”）
公共列表getAllProjects（@PathVariable String proID）{
返回bdProjectService.getAllProjects（proID）；
}
@请求映射（“/bdusers/{userID}/bdprojects/{proID}”）
公共BDProject getProject（@PathVariable字符串proID）{
返回bdProjectService.getProject（proID）；
}
@RequestMapping（method=RequestMethod.POST，value=“/bdusers/{userID}/bdprojects”）
public void addProject（@RequestBody BDProject BDProject，@PathVariable String userID）{
setBdUser（新的BDUser（userID，“，”，“）；
bdProjectService.addProject（bdProject）；
}
@RequestMapping（method=RequestMethod.PUT，value=“/bdusers/{userID}/bdprojects/{proID}”）
public void updateProject（@RequestBody BDProject BDProject，@PathVariable String userID，@PathVariable String proID）{
setBdUser（新的BDUser（userID，“，”，“）；
bdProjectService.updateProject（bdProject）；
}
@RequestMapping（method=RequestMethod.DELETE，value=“/bdusers/{userID}/bdprojects/{proID}”）
public void deleteProject（@PathVariable字符串proID）{
bdProjectService.deleteProject（proID）；
}

}

服务

@Service
public class BDProjectService {

@Autowired
private BDProjectRepository bdProjectRepository;

public List<BDProject> getAllProjects(String userID){
    List<BDProject> bdProjects = new ArrayList<>();
    bdProjectRepository.findByUserID(userID).forEach(bdProjects::add);
    return bdProjects;
}

public BDProject getProject(String proID){

    return bdProjectRepository.findById(proID).orElse(null);
}

public void addProject(BDProject BDProject){

    bdProjectRepository.save(BDProject);
}

public void updateProject(BDProject BDProject){

    bdProjectRepository.save(BDProject);
}

public void deleteProject(String proID){

    bdProjectRepository.deleteById(proID);
}

}

@服务
公共类BDProjectService{
@自动连线
私有BDProjectRepository BDProjectRepository；
公共列表GetAllProject（字符串用户ID）{
List bdProjects=new ArrayList（）；
bdProjectRepository.findByUserID（userID）.forEach（bdProjects:：add）；
返回项目；
}
公共BDProject getProject（字符串项目ID）{
返回bdProjectRepository.findById（proID）.orElse（null）；
}
公共无效添加项目（BDProject BDProject）{
bdProjectRepository.save（BDProject）；
}
公共无效更新项目（BDProject BDProject）{
bdProjectRepository.save（BDProject）；
}
公共项目（字符串项目ID）{
bdProjectRepository.deleteById（proID）；
}
}

存储库

public interface BDProjectRepository extends CrudRepository<BDProject, String>{

    public List<BDProject> findByUserID(String userID);

}

公共接口BDProjectRepository扩展了Crudepository{
公共列表findByUserID（字符串userID）；
}

---

非常感谢您的任何帮助。谢谢

您已经为BDProject实体创建了BDProjectRepository接口。 请修改该存储库中的方法：

现在：

公共列表findByUserID（字符串userID）

应该是：
公共列表findByProID（字符串proID）

如果要获取特定用户的BDProject，可以通过查询相关对象来检索它

公共列表findByBdUser\u用户id（字符串proID）
当通过引用对象中的字段进行查询时，您应该像编写ChildObject\u ChildID一样编写它

公共接口BDProjectRepository扩展了Crudepository
{
公共列表findByBdUser_UserID（字符串UserID）；
}
在BDProject中，您拥有属性

private BDUser bdUser;

在存储库中，您有：

public List<BDProject> findByUserID(String userID);

@jak_taylor123对端点使用GetMapping、PutMapping、PostMapping和DeleteMapping，而不是RequestMapping
public List<BDProject> findByUserID(String userID);

findByUserID(String userID) to findByBdUserUserID(String userID)