<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-validation</artifactId>
</dependency>
public class User {
private String username;
private String password;
private String email;
}
@RestController
@RequestMapping("/register")
public class UserController {
@PostMapping
public ResponseEntity<String> registerUser(@Valid @RequestBody User user) {
}
}
@ControllerAdvice
public class ValidationExceptionHandler {
@ExceptionHandler(MethodArgumentNotValidException.class)
public ResponseEntity<String> handleValidationException(MethodArgumentNotValidException ex) {
BindingResult bindingResult = ex.getBindingResult();
String errorMessage = bindingResult.getFieldErrors().stream()
.map(DefaultMessageSourceResolvable::getDefaultMessage)
.collect(Collectors.joining(", "));
return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(errorMessage);
}
}
