Can I create custom validation annotation that inherits from javax.constrains annotations - java

I'm wondering if it's possible to do something like:
#Min(1)
#Max(100)
public #interface ValidationForX {}
and then
#ValidationForX
int X;
For some reason #Min and #Max are applicable on annotations so I'm assuming it should be possible
I want to hide this validation behind one annotation because I want to reuse it
Thanks for your help!

You annotation must look like this:
#Min(1)
#Max(100)
#Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE})
#Retention(RUNTIME)
#Documented
#Constraint(validatedBy = {})
public #interface ValidationForX {
String message() default "value should be greater or equal than 1 and less or equal than 100.";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
Read more about composing constraints here: https://www.baeldung.com/java-bean-validation-constraint-composition

You can directly use #Min and #Max annotation on top of the field which you want to validate.
Something like this:
#Max(value=100)
#Min(value=1)
int X;

Related

Validate UUID Restful service

I have a RESTful service which receives POST request with UUID values and writes them in DB. So the problem is to validate if UUID is valid or not. For this purpose I implemented custom annotation:
#Constraint(validatedBy = {})
#Target({ElementType.FIELD})
#Retention(RUNTIME)
#Pattern(regexp = "[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[34][0-9a-fA-F]{3}-[89ab][0-9a-fA-F]{3}-[0-9a-fA-F]{12}")
public #interface validUuid {
String message() default "{invalid.uuid}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
But for some reason it doesn't work, even if I pass valid UUID I constantly get an exception:
javax.validation.UnexpectedTypeException: HV000030: No validator
could be found for constraint 'javax.validation.constraints.Pattern'
validating type 'java.util.UUID'
Are there any options to validate UUID properly?
You cannot apply the #Pattern annotation to something (java.util.UUID) that is not a CharSequence. From the #Pattern annotation documentation (emphesizes mine):
Accepts CharSequence. null elements are considered valid.
Moreover, as far as I see you try to extend the behavior of the validation annotation handler by passing it to the new annotation definition.
If you wish to perform more complex validation, simply create your annotation without another validation annotations - their combining doesn't work like this. There must be something to recognize annotations and validate them.
#Target({ElementType.FIELD})
#Retention(RUNTIME)
#Constraint(validatedBy = UuidValidator.class)
public #interface ValidUuid {
String message() default "{invalid.uuid}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
Now, create a validator which implements ConstraintValidator<ValidUuid, UUID> and override the methods performing the validation itself.
public class UuidValidator implements ConstraintValidator<ValidUuid, UUID> {
private final String regex = "....." // the regex
#Override
public void initialize(ValidUuid validUuid) { }
#Override
public boolean isValid(UUID uuid, ConstraintValidatorContext cxt) {
return uuid.toString().matches(this.regex);
}
}
And apply the annotation:
#ValidUuid
private UUID uuId;
you can use UUID.fromString(...); and catch IllegalArgumentException

Changing default group in custom constraint annotations

I have a working custom class level constraint that validates all annotations that do not belong in a group. How can I change that to validate a specific group with that constraint?
This is the annotation class I have:
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Constraint(validatedBy = CheckCase.class)
#Documented
public #interface ValidName {
String message() default "{message}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
#Target({TYPE, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Documented
#interface List {
ValidName[] value();
}
}
Right now, the validation works only if I use:
#CheckCase(message = "Error message")
I would like to use this:
#CheckCase(message = "Error message", groups = CheckCaseGroup.class)
Do I have to change something in the following line?
Class<?>[] groups() default {};
Separate question:
If I run the validator without passing in a group, will it go through all validations including the ones that have a group, or will it go only through the ones that don't have a specified group? For example:
will running this:
validator.validate(inputData);
go through this annotations:
#NotBlank(groups = CheckCaseGroup.class)
or only this:
#NotBlank()

How to order Bean Validation

I have create a validation annotation to validate the content of a string. The definition of my annotation looks like this:
#NotNull
#Size(min = 2, max = 128, groups = First.class)
#Pattern(regexp = "^(?!WP_([0-9])+$)[A-Z_][A-Z0-9_-]+", groups = Second.class)
#Target({FIELD, ANNOTATION_TYPE})
#Retention(RUNTIME)
#Documented
#Constraint(validatedBy = {})
#GroupSequence(value={First.class, Second.class})
public #interface ValidIntentName {
String message() default "";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
My problem is that i cannot order the #Size and #Pattern execution. I've tried a couple of things but no luck so far.
Basically I need #Size to be executed before #Pattern
First and Second interfaces are defined. There are no errors during compilation is just that during run-time #Patter is executed before #Size.
Any idea what I'm doing wrong?
I'm running Java 8.
Thanks

Combining custom constraint validator annotation

So I have created a custom constraint validator annotation like so:
#Documented
#Constraint(validatedBy = PostcodeValidator.class)
#Target( { ElementType.METHOD, ElementType.FIELD })
#Retention(RetentionPolicy.RUNTIME)
public #interface Postcode {
String message() default "not a well-formed postcode";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
and I wanted to use it in combination with others like so:
#NotEmpty
#Postcode
private final String postcode;
But when attempting to test this I get the following:
java.lang.IllegalStateException: Duplicate key not a well-formed postcode
I was expecting it to fail the #NotEmpty constraint.
I know I can use composition to include one constraint within the other, but my question is, is it possible to use them as I am? And if so, what am I doing wrong?
Cheers,

Can I add a bean validation annotation with group?

I want to build a NotNull check that only work on Create group, so I can write like this
#Data
public static class TestDto {
#NotNullOnCreate
// #NotNull(groups = Create.class) // instead of this
private String id;
}
I create the NotNullOnCreate like this
#Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER})
#Retention(RUNTIME)
#Documented
#Repeatable(NotNullOnCreate.List.class)
#ReportAsSingleViolation
#Constraint(validatedBy = {})
#NotNull(groups = Create.class)
#interface NotNullOnCreate {
String message() default "{javax.validation.constraints.NotNull.message}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
#Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER})
#Retention(RUNTIME)
#Documented
#interface List {
NotNullOnCreate[] value();
}
}
This doesn't work, because composing constraint annotation's (see ConstraintDescriptorImpl#createComposingConstraintDescriptor) group will be set to host annotation's group('Default').
I also tried this Class<?>[] groups() default {Create.class};, but this is not allowed, the default group must empty.
How can I achieve this ? I don't want to write the group everywhere.
EDIT
Create HV-1355 Constraint annotation with explicit groups
Wrote a workable demo project hv-annotation-with-group
This is not possible at the moment. If you like, open an issue in the Hibernate Validator issue tracker and we can explore this feature.

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