<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>2.0.1.Final</version>
</dependency>
public class User {
@NotNull
@Size(min = 5, max = 20)
private String name;
@Min(18)
private int age;
}
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
public class Main {
public static void main(String[] args) {
User user = new User();
user.setName("John");
user.setAge(10);
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
Set<ConstraintViolation<User>> violations = validator.validate(user);
if (violations.isEmpty()) {
} else {
for (ConstraintViolation<User> violation : violations) {
System.out.println(violation.getMessage());
}
}
}
}
