import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
public class User {
@NotNull
@Size(min = 2, max = 20)
private String username;
@NotNull
@Size(min = 6, max = 20)
private String password;
}
public class Main {
public static void main(String[] args) {
User user = new User();
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
Set<ConstraintViolation<User>> violations = validator.validate(user);
if (!violations.isEmpty()) {
for (ConstraintViolation<User> violation : violations) {
System.out.println(violation.getMessage());
}
} else {
}
}
}
