Best practices for validation depending on actions Spring MVC

Question

I am trying to perform validation using Spring validation. I am wondering what is the best practice to perform validation that depends mainly on user\'s action, hereafter, I hav

Answer 1

Depends that you want to do it. All solutions are good if you apply in all of your validators the same and you want to validate some business logic, not only if it's null or not (for this purpose you can use the @Valid annotation and annotation @Not null in your objects).

For me, if I have an object Foo I only want one Validator for this object, and then I have several methods for validate the data depends of I need in my controllers, for example, one for saving new Foo or other one for validating before updating, etc...

Answer 2

Use JSR-303 Validation Groups, which are since Spring MVC 3.1 also supported by @Validated.

So, for each action you should have a method in your controller. Create a validation group for each possible action that has a different set of rules, e.g.

public interface Create {
}

public interface Evaluate {
}

Annotate Foo with the validation annotations including the group, e.g.

public class Foo {

    @NotNull(groups = { Create.class, Evaluate.class })
    private String name;

    ...

    @Min(value = 1, message = "Evaluation value needs to be at least 1", groups = { Evaluate.class })
    private int evaluation;

    ...
}

Then annotate the foo argument of your controller methods with the appropriate @Validated annotation, e.g. @Validated({Evaluate.class}) for the evaluate controller method.

You can find another example here (see item 2): http://blog.goyello.com/2011/12/16/enhancements-spring-mvc31/

Update: Alternatively, if for some reason you can't / don't want to use @Validated, you can use an injected Validator instance and pass the groups to its validate method. That's the way it was done before Spring 3.1 (as is the case in the article in your comment).