RequestBuilder和RequestCallback性能问题

Question

我使用GWT RequestBuilder并且我看到请求回调需要很长时间才能处理，尽管服务器端请求处理所需的时间很好，下面是我的代码，是否需要优先处理请求回拨所以它会很快处理

        RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, URLs.getHpEquipmentIndigoDetails(equipmentId));
        float timeStart = System.currentTimeMillis();
        builder.sendRequest(null, new RequestCallback() {
            @Override
            public void onResponseReceived(Request request, Response response) {
                if (SmartPlannerConstants.SUCCESS_STATUS == response.getStatusCode()) {
                final float currentTime = System.currentTimeMillis();
                Log.debug("Time consumed on send & recieve request " + (currentTime-timeStart));
                // Initialize widget and update UI 
            }

            @Override
            public void onError(Request request, Throwable exception) {
                SmartPlannerWindowManager.showError(exception);
            }
        });
            final float timeEnd = System.currentTimeMillis();
            Log.debug("Time consumed on send request " + (timeEnd-timeStart));



        Result:
        Time consumed on send request zero ms
        Firebug says request handling on server is 200 ms
        Time consumed on send & recieve request is 4000 ms