ModelMapper DTO-entity conversion

ModelMapper enables to convert DTO to an entity.

DTO를 이용 id 값을 드러내지 않게한다.

사용된 DTO를 entity(User class) 로 다시 변경하기위해 ModelMapper를 사용

You need to add ModelMapper bean at @SpringBootApplication. It let us use ModelMapper in different classes. 

ModelMapper @Bean을 @SpringBootApplication에 등록한다. 

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

    @Bean
    public ModelMapper modelmapper(){
        return new ModelMapper();
    }

}

import ModelMapper in a UsersController.

Use ModelMapper.map() method to convert DTO to an entity.

package travelmate.demo.Users;

//import ModelMapper
import org.modelmapper.ModelMapper;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.Errors;
import org.springframework.web.bind.annotation.*;

import javax.validation.Valid;

@RestController
@RequestMapping("/user")
public class UsersController {

    private final UsersRepository usersRepository;
    private final ModelMapper modelMapper;

    public UsersController(UsersRepository usersRepository, ModelMapper modelMapper){
        this.usersRepository = usersRepository;
        this.modelMapper = modelMapper;
    }

    @PostMapping
    public ResponseEntity insertUser(@RequestBody @Valid UserDto userDto, Errors errors) {
        if(errors.hasErrors()){
            return ResponseEntity.badRequest().body(errors);
        }
        //conversion from userDto to an entity
        User user = modelMapper.map(userDto, User.class);
        //Use save method of JpaRepository to save entity
        User createdUser = usersRepository.save(user);

        return ResponseEntity.ok().body(createdUser);
    }

    @GetMapping
    public ResponseEntity signIn() {

        return ResponseEntity.ok().body(null);
    }

}

reference

https://www.baeldung.com/entity-to-and-from-dto-for-a-java-spring-application