I am using ExtJS ajax to send a data request to geoserver (which is in another domain different from web server), codes are as follows:

Ext.Ajax.request({ //send data request
        url : '../proxy.py?url=' + dataUrl,
        method : 'GET',
        headers: {
            'Content-Type': 'application/json'
        success : function(response, opts) {
            var eventData = Ext.decode(response.responseText); //decode into JSON

            //parse eventData
        failure: function(response, opts){
            Ext.Msg.alert("Failure", "Failed to retrieve event, please check service connection at " + dataUrl);                                    

since it relates to cross-domain issue, we employed a python proxy at web server, and put the GeoServer domain into the accessible list. If I put the request url in browser then I can get the JSON response; however by using ajax call in code, we got following error:

    <ows:Exception exceptionCode="MissingParameterValue" locator="request"> 
<ows:ExceptionText>Could not determine geoserver request from http request GET /geoserver/ows?service=WFS HTTP/1.1 
    Accept-Encoding: identity&#xd; 
    Host: XXXX&#xd; 
    Connection: close&#xd; 
    User-Agent: Python-urllib/2.5&#xd; &#xd; 
    </ows:ExceptionText> </ows:Exception>

I searched online, somebody said it's an issue related with proxy and the request headers. however, no detailed solution is found yet. I hope someone here can help me out.

thanks a lot!

UPDATE: using escape() to escape the request URL!

1 Answer 1


If you send in URL only:


you get this error. Minimal URL should be:


if you need capabilities call with this params. If you need GeoJSON request for layer URL should be like this:



in JS you should use encodeURIComponent to encode URL. escape() function shouldn't be used to encode URIs.

  • thanks for your reply. it turns out that I need to escape the URL, at least to escape the '?', '&' etc. So I use escape() and it's done. I don't know network request much, so really don't understand why this happens.
    – Simon
    Nov 15, 2011 at 22:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.