Custom Validation Not Working on spring boot - regex

Question

I am trying to implement custom validation in spring boot but there is some issue with the code even if I am passing wrong phone number the phone number should be 10 digit but I am passing a string and still I get status as OK can anyone tell me what is wrong with my code
#Data
public class StudentData {
#Phone
String phone;
}
#RestController
public class HomeController {
#PostMapping("/showData")
public String display(#Valid #RequestBody StudentData studentData){
return "OK";
}
}
#Documented
#Constraint(validatedBy = PhoneValidation.class)
#Target( { ElementType.METHOD, ElementType.FIELD })
#Retention(RetentionPolicy.RUNTIME)
public #interface Phone {
String message() default "{Wrong phone}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
public class PhoneValidation implements ConstraintValidator<Phone, String> {
#Override
public void initialize(Phone phone) { }
#Override
public boolean isValid(String phoneField, ConstraintValidatorContext constraintValidatorContext) {
if(phoneField == null) {
return false;
}
if(phoneField.matches("^[0-9]*$"))
return true;
return false;
}
}
Payload I am passing
http://localhost:8080/showData
{
"phone":"abc"
}

Answer 1

Try adding #Validated to your controller.
If that does not work, I would also confirm that validation code is being hit. Running your API in debug mode with a breakpoint in the isValid method can confirm if this is a problem in the validation logic, the Bean validator injection or your test setup (is it a test scenario?).

Answer 2

First, you don't need to use #Validated over #RestController, servlet container will validate it for you on data input annotated with #Valid
Second, your regex validates all strings consisting of digits, in spite of their length, so "1" or "22222222222222222" is a valid Phone
And last but not least - your code is working as desired :)