Question

I have a method in my controller which will handle the exceptions thrown by the application. So I have a method like this one.

@Controller
public class ExceptionController {

    @RequestMapping(value="/error")
    @ExceptionHandler(value={Exception.class, NullPointerException.class})
    public String showError(Exception e, Model model){
        return "tiles:error";
    }
}

And to try I if it works I throw a NullPointerException in another method in other method controller:

boolean a = true;
if(a){ 
    throw new NullPointerException();
}

After the exception is thrown it is printed in the JSP, but it doesn’t go throw my showError() method (I’ve set a breakpoint there and it never enters). showError() method will catch the exception and will show different error pages depending on the exception type (though now it always shows the same error page). If I go to the url /error it shows the error page so the showError() method is OK.

I’m using Spring 3.

What can be the problem?

Thanks.

Answer 1

If you look at your logs, you’ll probably see this:

java.lang.IllegalStateException:
Unsupported argument
[org.springframework.ui.Model] for
@ExceptionHandler method

In other words, @ExceptionHandler methods are not permitted to declare a Model parameter (see docs).

Remove that parameter (which you’re not using anyway), and it should work as expected.