I have developed application using SmartGWT, now i need to call webservice using json to another application which is deployed in another server for submitting username and password. When i make a request with url and POST method, getting the response status code as 0 and response text as blank.

Here is my code,

public void sendRequest() throws Exception {

// Get login json data to be sent to server.
String strData = createLoginReqPacket();
String url = "some url";
RequestBuilder builder = new RequestBuilder(RequestBuilder.POST, url);
builder.setHeader("Content-Type", "application/json");
builder.setHeader("Content-Length", strData.length() + "");



Request response = builder.sendRequest(strData, new RequestCallback() {

    @Override
    public void onResponseReceived(Request request, Response response) {

        int statusCode = response.getStatusCode();
        System.out.println("Response code ----"+response.getStatusCode()+"");

        if (statusCode == Response.SC_OK) {
            String responseBody = response.getText();
            System.out.println("Respose :" + responseBody);
            // do something with the response
        } else {
            GWT.log("Response error at server side ----",null);
            // do in case of server error
        }

    }// end of method.

    @Override
    public void onError(Request request, Throwable exception) {
        GWT.log("**** Error in service call ******",null);
    }// end of method.
});

builder.send();

}// end of send request.

Please anybody knows the solution?? Give some reference code or links for this.

Thanks.