在Spring 3 MVC中验证@RequestParam

Question

How do I validate Spring @RequestParam so that they are in BindingResult with out having to use some sort of POJO transfer object (@ModelAttribute)?

I could use MapBindingResult and put the request parameters in that but then I have to get that binding result into the model.

Which I can do with org.springframework.validation.BindingResult.MODEL_KEY_PREFIX + name.

Is there a better way to bind and validate request parameters (instead of making another POJO)?

Answer 1

If you are using Spring MVC 3.0 or later, you can use the declarative validation support Spring provides. You would then declare the validation restrictions on the model bean and add the @Valid annotation to your form backing bean as described in the chapter "Spring Validation" in the reference docs.

If you add a BindingResult parameter directly after the bean being validated, you can then check for validation errors in your controller:

// .. in the bean class
public class MyBean {
    @NotNull
    private String name;
    // ..
}

// .. in the @Controller
public ModelAndView doSomething(@Valid MyBean data, BindingResult bindingResult) {
    if (bindingResult.hasErrors()) { 
        // back to form
    }
    // do something with the bean
}