Find user by role using spring data jpa

Question

My User Entity

@Entity
public class User {

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

    @Column(nullable = fals         


        

Answer 1

Here from User to Role is ONE-TO-MANY mapping
i.e list of Roles is an element of User entity, and you are passing a String as List of Roles.
This is the reason you are getting Exception.

Solutions:

• Use findByRolesIn(List<String> roles) instead of findByRoles(String role)

• Or, Make one-to-one mapping as below:

  @Column(nullable = false)
  private String role;
  

• Or, Use JPA Query or Native query as below.

  @Query( "select u from User u  where u.roles in :roles" )
  public List<User> findByRoles(@Param("roles") List<String> roles);
  

Answer 2

In your UserRepository use in this way

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

import java.util.Collection;
import java.util.List;

public interface UserRepository extends JpaRepository<User, Long> {
    List<User> findByRolesIn(Collection<String> names, Pageable pageable);
}

In your Controller

@GetMapping(value = "/api/usersByRole/{userRole}")
public List<User> getUser(@PathVariable String userRole, Pageable pageable){
    return userRepository.findByRolesIn(Arrays.asList(userRole), pageable);
}

And You will have result like this