Handling forwarding errors

Question

Hi,
          Is it possible to checkfor the existance of a JSP page / servlet?
          I want to achieve something like this in a servlet...
          forward to page1.jsp
               if failed(page not exist), forward to page2.jsp
                    if failed(page not exist), forward to page3.jsp
          However, using RequestDispatcher.include() to a non-existant page seems
          to hang waiting for something.
          Using RequestDispatcher.forward() to a non-existant page just sends a 404
          to the client.
          If either would throw an exception, I could catch it and forward to my next
          required page. Am I missing something obvious, or does the JSP spec not
          allow for this kind of thing?
          Thanks,
          Martin.
          

Answer 1

Thanks Anirudh,
In Flash Builder, try doing
if(this.hasOwnProperty("d") && this["d"] == 1){ }
I was just throwing this error as an example of throwing an error, and not looking to fix it in particular.  We have a large and complex application which is used by many people.  Unfortunately, some of our users are experiencing runtime errors that are stopping the execution of the script - and we do not know exactly where those are.  They may be easy to fix once we can locate them. Unfortunately, we have not been able to reproduce them locally.
If the flash player encounters an error in the constructor of the sprite/movieclip which is the main class, it will not be able to continue. If this error had occurred in an event handler, then you'd be able to continue.
Can you tell us more about the rules of uncaught runtime error handling? For example: when I compile this code - the sprite is not shown on the stage and the second trace is not executed - despite having moved the code to an event handler function.
package
import flash.display.MovieClip;
import flash.display.Sprite;
import flash.events.Event;
import flash.events.TimerEvent;
import flash.utils.Timer;
import org.osmf.events.TimeEvent;
public class ErrorTest extends MovieClip
public function ErrorTest()
var t:Timer = new Timer(100, 1);
t.addEventListener(TimerEvent.TIMER, eventHandler);
t.start();
protected function eventHandler(e:Event):void {
trace("1");
if(this["d"] == 1){}
trace("2");
var s:Sprite = new Sprite();
s.graphics.beginFill(0xFFCC00);
s.graphics.drawRect(0,0,200,200);
addChild(s);
I'd like to publish our application such that it would ignore all run time errors. Are there any compiler or other options to achieve that.
Ideally we'd like to collate the errors such that end users could open a hidden text field and copy the error messages and send them to us.