annotation-based validation framework

Question

Hi,

I'm looking for an annotation-based validation framework, that would allow me to validate parameter values. Something like the following:

void someMethod(@NotBlank String foo, @NotEmpty Collection bar, @Positive Integer baz, @NotNull Object obj) {

}

Validation of the parameters should happen automatically whenever an annotated method/constructor is called, so that there no way to bypass the validation.

If I could customise the error messages produced that would be nice. I'm using Java 1.5.

Thanks, Don

Answer 1

That's a job for a JSR 303 - Bean Validation implementation, like Hibernate Validator (the RI). Check the various Bean Validation blog posts from Emmanuel Bernard (the spec lead).

Answer 2

Try taking a look at OVal and others implementors of the JSR-303 (aka Bean validation)