Could you be running into the SOP (same origin policy) problem? If your GWT and CGI script are running on different hosts the GET/POST requests won't work. See: http://code.google.com/docreader/#p=google-web-toolkit-doc-1-5&s=google-web-toolkit-doc-1-5&t=FAQ_SOP http://code.google.com/docreader/#p=google-web-toolkit-doc-1-5&s=google-web-toolkit-doc-1-5&t=GettingStartedJSON (scroll down to the SOP section for potential workarounds).
Hope this helps. On Nov 9, 7:47 pm, dk <[email protected]> wrote: > Hi, > > This is about GWT 1.7.1 on a RedHat EL 5.4 system. > > I have been messing with GWT for a while now. I am not an expert and > am really still a java newbie. I have the following code snippet > in an application I am writing. There is an existing CGI app and > I am replacing the GUI with GWT and using the existing CGI scripts > for the data operations. > > I am setting up a RequestBuilder call to retrieve data from a CGI > script. That script generates data and sends it as a JSON string back > to this routine. The issue is that I am receiving an: > > empty argument > > message that is generated by the JSONParser. The message comes > through the catch clause that holds the > > LOG("getInfo:onResponseReceived:e2:" > > line. > > I *know* the CGI script is doing its thing. I can run it from the > command line and visit its URL and I get JSON'd data that looks OK > to my eye. The code section looks like: > > public void getInfo() { > RequestBuilder req; > LOG("getInfo:a"); > > req = new RequestBuilder(RequestBuilder.GET, > URL.encode(baseURL + "archive.cgi")); > > LOG("getInfo:b:"+req.getUrl()); > > try { > req.sendRequest(null, new RequestCallback() { > public void onError(Request request, Throwable e) { > Window.alert("getInfo failed: " + e.toString()); > } > > public void onResponseReceived(Request request, > Response response) { > JSONObject Info; > try { > LOG("getInfo:onResponseReceived:a:"); > Info = JSONParser.parse(response.getText() > ).isObject > (); > } > catch (NullPointerException e) { > LOG("getInfo:onResponseReceived:e1:" + > e.getMessage()); > throw new RuntimeException( > "Failed to send JSON > request"); > } > catch(IllegalArgumentException e) { > LOG("getInfo:onResponseReceived:e2:" + > e.getMessage()); > throw new RuntimeException( > "Failed to send JSON > request"); > } > catch(Exception e) { > LOG("getInfo:onResponseReceived:e3:" + > e.getMessage()); > throw new RuntimeException( > "Failed to send JSON > request"); > } > > Here is a sample JSON'd string. > > {"searchTerm":"","pending":["<h2>Calendar for Fall 2009</h2> > \n","<h3>Tuesday, November 10, 2009<br/>MRI Stuff</h3>\n<h4>Speaker: > Andrew <a href=\"mailto:[email protected]\";><img src=\"/images/email.jpg > \" alt=\"(email)\"/></a>, Radiology and Biomedical Engineering</h4> > \n<h4>Time: 12:00PM</h4>\n<h4>Location: Room 5602</h4>\n<h4>Abstract:</ > h4>\n<p>Transcatheter and percutaneous liver-directed approaches are > widely used for the treatment of ... procedures.</p>\n","<h3>Tuesday, > November 17, 2009<br/>Title Forthcoming</h3>\n<h4>Speaker: Chas > Conway</h4>\n<h4>Time: 12:00PM</h4>\n<h4>Location: </h4> > \n<h4>Abstract:</h4>\n<p>Abstract Forthcoming</p>\n","<h3>Tuesday, > November 24, 2009\n<br/>No Forum - Thanksgiving Vacation</h3> > \n","<h3>Tuesday, December 1, 2009<br/>Title Forthcoming</h3> > \n<h4>Speaker: Yi Lu, Professor</h4>\n<h4>Time: 12:00PM</h4> > \n<h4>Location: </h4>\n<h4>Abstract:</h4>\n<p>Abstract Forthcoming</p> > \n","<h3>Tuesday, December 8, 2009<br/>Title Forthcoming</h3> > \n<h4>Speaker: </h4>\n<h4>Time: 12:00PM</h4>\n<h4>Location: </h4> > \n<h4>Abstract:</h4>\n\n","<h3>2009-12-09<br/>Fall Semester Ends</h3> > \n"]} > > This was produced from a Perl cgi script using CGI.pm and JSON::XS > > FireFox/FireBug shows the request call and the headers but the result > is missing. > > This code is not really different than other working code and the > CGI is not really all that different either. > > I have tried using a POST method and setting > > req.setHeader("Content-Type", "application/x-www-form- > urlencoded"); > > though I am not "sending" any data to the script. > > I have tried setting > > req.sendRequest(null, new RequestCallback() { > req.sendRequest("", new RequestCallback() { > req.sendRequest("dummy=value", new RequestCallback() { > > and it is still happening. > > It must be something very trivial that I am not seeing. Can you help? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en -~----------~----~----~----~------~----~------~--~---
