Spring Boot JPA find by custom String field

Question

I'm trying to get a list of models based on a custom string field. From the User class, I want to search the database and retrieve all models that contain a specific role value.

Model class

@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id; 

    private String role;
    ...

}

Repository class

@Repository
public interface UserRepository extends JpaRepository<User, Long>{
    List<User> findById(@Param(value = "id") Long id);
    List<User> findByRole(@Param(value = "role") String role);
}

Service class

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;
    
    public List<User> getAllUsers() {
        return userRepository.findAll();
    }

    
    public List<User> findUserById(@PathVariable("id") Long id){
        return userRepository.findById(id);
    }

    public List<User> findUserByRole(String role){
        return userRepository.findByRole(role);
    }
    ...
}

Controller class

@RestController
@RequestMapping("/api/users")
public class UserController {

    @Autowired
    UserService userService;

    @GetMapping
    public List<User> accessUsers() {
        return userService.getAllUsers();
    }

    @GetMapping("/{id}")
    public List<User> findById(@PathVariable("id") Long id){
        return userService.findUserById(id);
    }

    @GetMapping("/{role}")
    public List<User> findByRole(@RequestParam(value="role") String role){
        return userService.findUserByRole(role);
    }
    ...
}

I make the request as follows (where role=MANAGER):

GET localhost:8080/api/users/MANAGER

However, I get this error. I noticed that if I'm trying to get models based on a Long id value it works, but whenever I attempt to do it with a String field, it gives the error:

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: Ambiguous handler methods mapped for '/api/users/CHEF': {public java.util.Optional com.cs322.ors.controller.UserController.accessUserInfo(long,org.springframework.security.core.Authentication), public java.util.List com.cs322.ors.controller.UserController.findByRole(java.lang.String)}

I tried the following links but the issue persists:

score 0 · Answer 1 · answered Nov 28 '20 at 19:16

A friend helped me figure out the problem.

When mapping out the route GET localhost:8080/api/users/MANAGER, Spring Boot doesnt know if I'm specifying GET localhost:8080/api/users/{id} or GET localhost:8080/api/users/{role}. Since they have the same url, it cant decide between the id and the role. To fix this, I added a more specific endpoint like the following below:

    @GetMapping("roles/{role}")
    public List<User> findByRole(@PathVariable("role") String role){
        return userService.findUserByRole(role);
    }

Spring Boot JPA find by custom String field

1 Answers1