Question

我正在用Spring Boot，JPA和H2开发JavaFx应用程序。当我尝试向数据库中添加新用户时，我有一个用户实体，它会在按钮的单击操作上向控制器中抛出NPE。如图所示，我仅使用自动装配符号。我研究了但是调查结果并没有帮助。有什么帮助吗？

package com.core;

@SpringBootApplication
@Import(SharedSpringConfiguration.class)
public class Runner extends Application {

   private ConfigurableApplicationContext context;

   public static void main(String[] args) {
     launch(args);        
   }

   @Override
   public void init() {
    context = SpringApplication.run(Runner.class);
   }
}

package com.dao;

@Entity
@Table(name = "user")
public class User {

    @Id
    @Column(name = "id", updatable = false, nullable = false)
    private long ID;
    @Column(nullable = false)
    private String userName;
    @Column(nullable = false)
    private String userPass;

    public User() {
    }

    public User(long ID, String userName, String userPass) {
        this.ID = ID;
        this.userName = userName;
        this.userPass = userPass;
    }
}

package com.service;

@Service
public class UserService {

   @Autowired
   private UserRepository userRepository;

   public UserService() {
   }

   public void saveUser(User user) {
     userRepository.save(user);
   }
}

package com.repository;
public interface UserRepository extends CrudRepository<User, Long> {}

package com.controller

@Controller
public class MethodController implements Initializable {

  @Autowired
  private UserService userService;

  @FXML
  void methodSave(MouseEvent event) {
    userService.saveUser(new User(11, "TestUser", "noPass")); //Throws NPE. Indicates that userService is null. But I autowire the userService.
  }
}

Answer 1

我不知道mesh = plt.pcolormesh(...) colors = mesh.cmap(mesh.norm(mesh.get_array()))中有什么，但是您可能需要在其中一个配置类上使用SharedSpringConfiguration。不必在CrudRepo上使用@EnableJpaRepositories。

Answer 2

将您的SpringBootApplication软件包从com.core更改为com

因为默认情况下，SpringBootApplication将仅扫描该软件包和子软件包。

其他

在SpringBootApplication中添加@ComponentScan批注并扫描软件包。

Spring Boot JPA空指针异常

2 个答案: