I have and Google Web Toolkit (Multipart) Form which post a file to my servlet. When error condition is happening in servlet I return an error. When everything is OK I return an JSON string.

    ...
    response.setContentType("text/html");
    response.setCharacterEncoding("UTF8");
    response.getWriter().write(out.toString());

} catch (FileUploadException e) {
    response.sendError(500, e.getMessage());
} catch (Exception e) {
    response.sendError(500, e.getMessage());
}

The problem is that I cant find a way to handle this in client side. This is the event that is fired when post goes OK and when error code is returned. But I can't find how to find is it OK or NOT? And how can I get an error message from Exception in client code?

@UiHandler("form")
void submitComplete(SubmitCompleteEvent event)
{
    ...

I have and Google Web Toolkit (Multipart) Form which post a file to my servlet. When error condition is happening in servlet I return an error. When everything is OK I return an JSON string.

    ...
    response.setContentType("text/html");
    response.setCharacterEncoding("UTF8");
    response.getWriter().write(out.toString());

} catch (FileUploadException e) {
    response.sendError(500, e.getMessage());
} catch (Exception e) {
    response.sendError(500, e.getMessage());
}

The problem is that I cant find a way to handle this in client side. This is the event that is fired when post goes OK and when error code is returned. But I can't find how to find is it OK or NOT? And how can I get an error message from Exception in client code?

@UiHandler("form")
void submitComplete(SubmitCompleteEvent event)
{
    ...

• java
• javascript
• gwt
• servlets
• file-upload

• You could override the default error documents (in your server's configuration) so that they just output, for example, the status code - it would be easier to search for "500" in the response, then parse the whole default error page. – Igor Klimer Commented Aug 11, 2010 at 8:43
• @Igor Klimer: Is it worth to change the server configuration for just one servlet? Why I can't find response code (200 or 500)? – Julian Popov Commented Aug 11, 2010 at 9:04
• Well, it is weird that you don't have access to the response code, like in RequestBuilder... But it seems nothing can be done for now (maybe create a new issue/improvement on GWT's bug tracker?) Two related threads from GWT's group: groups.google./group/google-web-toolkit/browse_thread/thread/… and groups.google./group/google-web-toolkit/browse_thread/thread/…. It seems it's important to set content-type of your response to text/html to ensure it works on all browsers (even if it actually contains JSON). – Igor Klimer Commented Aug 11, 2010 at 9:23
• @Igor Klimer Thank you very much :) It seems that I have to return error messages with code 200 or change server configuration (or ignore everything returned from servlet that is not correct JSON) – Julian Popov Commented Aug 11, 2010 at 9:37
• Glad I could help :) I've added an answer summarizing the above ments, so that someone else could easier find the answer to this question. – Igor Klimer Commented Aug 11, 2010 at 12:38

1 Answer 1

Currently, there doesn't seem to be a suitable method available (like Response's getStatusCode). You have to do with the error documents your server returns to you in SubmitCompleteEvent.getResults(). You can make this task easier by setting custom error documents on your server (which you should either way for your production server) that are easier to parse/handle.

Related threads on GWT's Google Group: one and two.