Handlling GWT call failure

Hello I have a piece of code in GWT, A senior colleage of mine has written this code.

public void onFailure(Throwable caught) {

    if (caught instanceof RuntimeException) {

        if (caught instanceof StatusCodeException
            && caught.getMessage().contain开发者_Python百科s(
                "<title>Error 500 unAuthorized</title>")) {
            MessageBox
                .alert("Session has been expired. Press Ok to redirect to Login page.");
            History.newItem(HistoryToken.INDEX_PAGE.toString());
         } else {
        MessageBox
            .alert("An exception has occured.Press Ok to continue.");
         }

    } else if (caught instanceof InvocationException) {
        MessageBox
            .alert("Sorry... Some error occured while reaching to server.");

    }
}

What are the chances of executing else if (caught instanceof InvocationException) { block when call failed on server ?

I think else if (caught instanceof InvocationException) will not get executed in any case. Any Suggestions ?

Because InvocationException is a subclass of RuntimeException (as the docs say), you are correct.

BTW, is there any reason your senior colleague does a string comparison on getMessage instead of checking the status code with getStatusCode()? (See here)