How do I test gwt requestbuilder with junit in gwttestcase?

My GWT application contains data that needs to be read from client side xml files. For this I am using RequestBuilder.

RequestBuilder builder = new RequestBuilder(RequestBuilder.GET,GWT.getHostPageBaseURL()+"myFile.xml");

      

        
        
        
      

    

try {builder.sendRequest (null, new RequestCallback () {@Override public void onResponseReceived (request request, response response) {

       // read out data and put into to a list

   }

      

        
        
        
      

    

}); .........

The data will be read out, put into a list, and from that list, data will be put into the view. How can I check this? When I try this in a GWTTestCase class with some assertEquals methods inside onResponseReceived I get this error message:

[WARN] 404 - GET / com.test.app.appName.JUnit / myFile.xml (192.168.2.102) 1466 bytes Request headers Host: 192.168.2.102:51731 User-Agent: Mozilla / 5.0 (Windows; U; Windows NT 5.1; en-US; rv: 1.9.0.19) Gecko / 2010031422 Firefox / 3.0.19 Accept language: en-us Accept: / Connection: Keep-Alive Referer: ht t_p: //192.168.2.102: 51731 / com. test.app.appName.JUnit / junit-standards.html? Gwt.codesvr = 192.168.2.102: 51727 Content-Type: text / plain; encoding = UTF-8 Response headers Content-Type: text / html; encoding = iso-8859-1 Content-Length: 1466

What am I doing wrong? Please, help.