Override Generic Controller - spring-mvc

Question

I have the following function in my abstract controller
public abstract class GenericController<T extends PersistentObject> {
...
...
...
#RequestMapping(value = "/validation.json", method = RequestMethod.POST)
#ResponseBody
public ValidationResponse ajaxValidation(#Valid T t, BindingResult result) {
ValidationResponse res = new ValidationResponse();
if (!result.hasErrors()) {
res.setStatus("SUCCESS");
} else {
res.setStatus("FAIL");
List<FieldError> allErrors = result.getFieldErrors();
List<ErrorMessage> errorMesages = new ArrayList<ErrorMessage>();
for (FieldError objectError : allErrors) {
errorMesages.add(new ErrorMessage(objectError.getField(),
objectError.getDefaultMessage()));
}
res.setErrorMessageList(errorMesages);
}
return res;
}
At most cases the validation is sufficient for different kind of entities. Now I would like to customize the validation on my concrete controller as
#Controller
#RequestMapping("user")
public class UserController extends GenericController<User> {
#RequestMapping(value = "/validation.json", method = RequestMethod.POST)
#ResponseBody
public ValidationResponse ajaxValidation(#Valid User user,
BindingResult result, Locale locale) {
ValidationResponse res = super.ajaxValidation(user, result);
if (!user.getPassword().equals(user.getConfirmPassword())) {
res.setStatus("FAIL");
res.getErrorMessageList().add(
new ErrorMessage("confirmPassword", messageSource
.getMessage("password.mismatch", null, locale)));
}
return res;
}
}
With this I get the following error java.lang.IllegalStateException: Ambiguous mapping found. Cannot map 'userController' bean method. How can I solve this issue ? Is there a better approach ?

Answer 1

The problem here is that after extending your generic controller you have two different methods
public ValidationResponse ajaxValidation(#Valid T t, BindingResult result)
and
public ValidationResponse ajaxValidation(#Valid User user,
BindingResult result, Locale locale)
with the exact same mapping
user/validation.json
An ugly solution would be to add the Locale locale param to your abstract controller method (even if you don't use it) and add the #Overwrite annotation to the UserController method (you'll get a compilation error otherwise). This way the two methods become one.

Answer 2

The generic controller is extended by other classes ? Then you will have two identical requestmappings.
Are you sure the UserController is correctly getting user prepend request mapping applied ? As this works :
#RequestMapping("test")
public class ExampleController extends AbstractController {
#RequestMapping(value = "/Home", method = RequestMethod.GET)
public String getHome(Model model) {
return "home";
}
with the same mapping in AbstractController
#RequestMapping(value = "/Home", method = RequestMethod.GET)
public String getHome(Model model) {
return "home";
}