<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>2.0.1.Final</version>
</dependency>
public class UserLogin {
private String username;
private String password;
}
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
import javax.validation.ConstraintViolation;
public class Main {
public static void main(String[] args) {
UserLogin user = new UserLogin();
user.setUsername(null);
user.setPassword("");
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
Set<ConstraintViolation<UserLogin>> violations = validator.validate(user);
if (!violations.isEmpty()) {
for (ConstraintViolation<UserLogin> violation : violations) {
System.out.println(violation.getMessage());
}
} else {
}
}
}
