The Problem
Two constraints were created and for each one, a validator was implemented (which executes the validation logic). Both constraints were used at field-level on JPA entities, the Username and FloatRange constraints were annotated on fields of type string and float, respectively. However, just the Username constraint worked.. Hereunder you can take a look at the implemented code, or part of it :)
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = UsernameValidator.class)
@Target({
ElementType.METHOD,
ElementType.FIELD,
ElementType.ANNOTATION_TYPE
})
public @interface Username {
String message() default "{constraint.username.invalid}";
Class<? extends Payload>[] payload() default {};
Class<?>[] groups() default {};
}
public class UsernameValidator
implements ConstraintValidator<Username, String> {
@Override
public void initialize(Username annotation) {}
@Override
public boolean isValid(String value,
ConstraintValidatorContext context) {
// validation logic ommited
}
}
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = FloatRangeValidator.class)
@Target({
ElementType.METHOD,
ElementType.FIELD,
ElementType.ANNOTATION_TYPE
})
public @interface FloatRange {
String message() default "{constraint.range}";
Class<? extends Payload>[] payload() default {};
Class<?>[] groups() default {};
float min();
float max();
}
public class FloatRangeValidator
implements ConstraintValidator<FloatRange, Float> {
private float min;
private float max;
@Override
public void initialize(FloatRange annotation) {
this.min = annotation.min();
this.max = annotation.max();
}
@Override
public boolean isValid(Float value,
ConstraintValidatorContext context) {
// validation logic ommited
}
}
The Solution
After a lot of googling and force brute tests... A co worker (Marcelo Yamashita) came with the solution. He tried to use the @FloatRange constraint at property-level, man... that worked! Then, reading more carefully the Hibernate Validator documentation, more specifically the item 2.1.1. Field-level constraints, i noticed the note that says:
Well, if i've got it right, by properties it means POJO fields which have getter/setter, or not? If so, then houston, we have a problem... both target annotated fields, belong to JPA entities thus, they have getters and setters! It doesn’t make them properties? Anyway, the workaround rocks, but if you have any idea about the why this happens, please, feel free to share it with the world :)Static fields and properties cannot be validated.
