I'm trying to validate a userDto class with @Valid sending a form-data from an angular application like this:

Angular Form:

this.form.append('email', this.user.email);
this.form.append('password', this.user.password);
this.form.append('firstName', this.user.firstName);
this.form.append('lastName', this.user.lastName);
this.form.append('photo', this.file.name);
this.form.append('enable', `${this.user.enable}`);
this.form.append('roles', JSON.stringify(this.user.roles));
this.form.append('file', this.file);

this.userService.createUser(this.form)

Controller class:

@PostMapping
    public ResponseEntity<Object> save(@Valid UserDto userDto, @RequestPart("file") MultipartFile file) throws IOException {
        service.save(userDto.convertToUser(userDto, file.getOriginalFilename()), file);
        return new ResponseEntity<>(HttpStatus.CREATED);
    }

UserDTO class:

@Data
@AllArgsConstructor
@NoArgsConstructor
public class UserDto {
    
    private Integer id;

    @NotEmpty(message = "email is required")
    private String email;
    
    @NotEmpty(message = "password is required")
    private String password;
    
    @NotEmpty(message = "first name is required")
    private String firstName;

    @NotEmpty(message = "last name is required")
    private String lastName;

    private String photo;
    private String enable;
    private String roles;

    public User convertToUser(UserDto userDto, String photoName) {

        User user = new User();

        ObjectMapper mapper = new ObjectMapper();
 
        try {
            List<Role> rolesDto = 
                     Arrays.asList(mapper.readValue(userDto.getRoles(),Role[].class));

            Set<Role> roles = Set.copyOf(rolesDto);

            user.setId(this.id);
            user.setEmail(this.email);
            user.setPassword(this.password);
            user.setFirstName(this.firstName);
            user.setLastName(this.lastName);
            user.setPhoto(photoName);
            user.setEnable(Boolean.parseBoolean(this.enable));
            user.setRoles(roles);
                           
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }

        return user;
    }
}

But if I pass an empty form-data the class that throws an exception is my User class, i wanted that the UserDto throw the exception not the User class.

I tried to use the @RequestBody annotation with @Valid but i'm using formdata in angular not json format.

Is there a way to validate a form-data in spring boot passing the form to a DTO class that do not have an @Entity annotation ?

CodePudding user response：

You can use the Validator interface from org.hibernate.validator to validate DTO's. For more info about Hibernate Validator. Or you can look through Spring boot : non-entity bean validation not working and Why does validation not work on objects of type DTO, but only on entities.

public class Car {

    @NotNull
    private String manufacturer;

    @NotNull
    @Size(min = 2, max = 14)
    private String licensePlate;

    @Min(2)
    private int seatCount;

    public Car(String manufacturer, String licencePlate, int seatCount) {
        this.manufacturer = manufacturer;
        this.licensePlate = licencePlate;
        this.seatCount = seatCount;
    }

    //getters and setters ...
}

package org.hibernate.validator.referenceguide.chapter01;

import java.util.Set;
import jakarta.validation.ConstraintViolation;
import jakarta.validation.Validation;
import jakarta.validation.Validator;
import jakarta.validation.ValidatorFactory;

import org.junit.BeforeClass;
import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class CarTest {

    private static Validator validator;

    @BeforeClass
    public static void setUpValidator() {
        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
        validator = factory.getValidator();
    }

    @Test
    public void manufacturerIsNull() {
        Car car = new Car( null, "DD-AB-123", 4 );

        Set<ConstraintViolation<Car>> constraintViolations =
                validator.validate( car );

        assertEquals( 1, constraintViolations.size() );
        assertEquals( "must not be null", constraintViolations.iterator().next().getMessage() );
    }

    @Test
    public void licensePlateTooShort() {
        Car car = new Car( "Morris", "D", 4 );

        Set<ConstraintViolation<Car>> constraintViolations =
                validator.validate( car );

        assertEquals( 1, constraintViolations.size() );
        assertEquals(
                "size must be between 2 and 14",
                constraintViolations.iterator().next().getMessage()
        );
    }

    @Test
    public void seatCountTooLow() {
        Car car = new Car( "Morris", "DD-AB-123", 1 );

        Set<ConstraintViolation<Car>> constraintViolations =
                validator.validate( car );

        assertEquals( 1, constraintViolations.size() );
        assertEquals(
                "must be greater than or equal to 2",
                constraintViolations.iterator().next().getMessage()
        );
    }

    @Test
    public void carIsValid() {
        Car car = new Car( "Morris", "DD-AB-123", 2 );

        Set<ConstraintViolation<Car>> constraintViolations =
                validator.validate( car );

        assertEquals( 0, constraintViolations.size() );
    }
}