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  1. Spring Framework
  2. SPR-15314

Increase reusability of Validator



    • Last commented by a User:


      Quick summary


      It would be really cool if the Validator implementations could be reused at the Service level hassle-free.

      It would be cool because:

      • It's a common scenario that there's a second request source using the same dto (think webmvc / rest and mq), adding the second source involves extra work if it doesn't provide the binding in an other way, without using implementations of the Errors interface
      • Increases code reuse, since we use the same Validator on both Service-level and Controller-level
      • Would promote validation at the service-level a bit

      Example scenario when that happens:

      1. There's a web-mvc project, `controller <dto> service`, at the controller-side the dto is validated with the Validator
      2. There's a business need to implement a secondary source of requests (let's say an mq)

      Now there's a possibility to reuse the Validator created for the controller at the service level, but for me it seems to involves quite a hassle, it would be nice to make that convenient.


      • Create an interface which implements the simplified Errors interface
        • Can be instantiated with the target object only
        • Doesn't necessary have to store all the rejected properties, tracking if there was any errors might be enough
      • Create an abstract class which implements Validator
        • Boolean validate(Object target) is implemented here

      The namings for me seem to be a bit weak, they could handle suggestions I'm pretty sure.

      For existing Validator implementations there's only need to extend this abstract class and it'll turn into a validator which is convenient to use at the service level, please see the attached java files, this might be a bit invasive although.


      This is just an idea and i'm kinda new to Spring and to Java in general so the proposal will probably include foolish design mistakes, i looked it up and so far i haven't seen anything which would make reusing of these easy, please point it out if there's already some.

      If that's cool to do and there's a consensus i could make a pr for this in the coming days.

      Let me know what you think!




            juergen.hoeller Juergen Hoeller
            danigu Daniel Gulyas
            Last updater:
            Spring Issues Spring Issues
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              3 years, 23 weeks, 6 days ago