1. Hibernate Validator
public class User {
@NotNull
private String name;
@Email
private String email;
// getters and setters
}
public class Main {
public static void main(String[] args) {
User user = new User();
user.setName("John");
user.setEmail("john@example.com");
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
Set<ConstraintViolation<User>> violations = validator.validate(user);
for (ConstraintViolation<User> violation : violations) {
System.out.println(violation.getMessage());
}
}
}
2. Apache BVal
public class User {
@NotNull
private String name;
@Email
private String email;
// getters and setters
}
public class Main {
public static void main(String[] args) {
User user = new User();
user.setName("John");
user.setEmail("john@example.com");
Validator validator = ApacheValidatorFactory.getDefault().getValidator();
ValidationResult result = validator.validate(user);
if (result != null && result.getViolations().size() > 0) {
for (ConstraintViolation<?> violation : result.getViolations()) {
System.out.println(violation.getMessage());
}
}
}
}
3. Spring Validation
public class User {
@NotEmpty(message = "Name cannot be empty")
private String name;
@Email(message = "Invalid email address")
private String email;
// getters and setters
}
public class Main {
public static void main(String[] args) {
User user = new User();
user.setName("John");
user.setEmail("john@example.com");
Validator validator = ValidationUtils.getValidator();
Errors errors = new BeanPropertyBindingResult(user, "user");
validator.validate(user, errors);
if (errors.hasErrors()) {
for (ObjectError error : errors.getAllErrors()) {
System.out.println(error.getDefaultMessage());
}
}
}
}
