I’m just wondering about data validation in Spring. Spring is offering two (maybe more) validation options. First option is to use Validator interface and create whole validation on my own. Second option is to use annotation validation (JSR 303).
And now I’m really confused 🙂 which validation I should chose. What I need is to check if recieved Data Object is correct (by correct i mean all required fields are filled) and this can be done by JSR 303 validation or by my own validator with “Validator instance”. But I also need to check if is this Data Object valid against some database constraints (validator is required to check some data in database, eq. is user with this ID registered or not …) and this can be done only by my own validator.
I don’t know which way should be the best. Combine both or create my own validator ?
I will be thankful for any advice …
Update (relocated from comments)
Ok, I followed Ryan’s example and I think I was successful. I created my own implementation of spring Validator and in this Validator I @Autowire-d javax JSR 303 instance. But there was problem with that injection. I had in my configuration and this piece of code caused some exceptions, because spring did not know which Validator I want to inject. So I removed that code.
At the end I also removed the spring Validator implementation, because I dont know where I can get Errors property, which is required as second parameter in “validate” method :). I’m triggering that validation manually from service layer and I really don’t know, where I can obtain that Error object.
BTW Well, I found another solution how to implement that validation. I’m thinking about to extend my validator class by LocalValidatorFactoryBean. LocalValidatorFactoryBean class implementing both Validator interfaces (Spring Validator + JSR 303). But i’m not sure if is this good approach. This approach also require Error object, which I don’t know where to find/get.
Update
The Error object is coming from “BindException”.
FooObjectVO myObject = new FooObjectVO();
BindException errors = new BindException("fooObject", myObject);
They’re not really separate options–more like two available implementations of validation. Since Spring’s JSR 303 support also implements its own Validator interface, you don’t really have to pick one or the other. You can mix and match the implementations in whatever way makes it easiest to get the job done.