Problems with RequestBuilder

Hello Dears, I have this code and looks like I have response but no show any thing, may you help me please? I am using GWT 2.8, java 1.8 with Eclipse and my service is in php slim and is working fine I attached 2 images. thank you in advance

RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, "http://localhost:8080/slim_prueba_3.0/services.php/hola");
 try
 {
 builder.sendRequest(null, new RequestCallback()
 {
 @Override
 public void onResponseReceived(Request p_request, Response p_response)
 {
 if (p_response.getStatusCode() == Response.SC_OK)
 {
 new VentanaMensaje().showWarning("onResponseReceived " + p_response.getText() + " (OK)");
 btnIngresar.enable();
 }
 else
 {
 new VentanaMensaje().showWarning(" onResponseReceived " + p_response.getText() + " (" + p_response.getStatusCode() + ")");
 }
 
 }
 @Override
 public void onError(Request p_request, Throwable p_e)
 {
 new VentanaMensaje().showWarning("Error");
 
 }
 });
 }
 catch (RequestException e)
 {
 new VentanaMensaje().showWarning("Excepcion");
 }

I have in console of eclipse this message only

Request headers
 Host: 127.0.0.1:8888
 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0
 Accept: /
 Accept-Language: es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3
 Accept-Encoding: gzip, deflate
 Referer: http://127.0.0.1:8888/principal.html
 Connection: keep-alive
 Response headers
 Date: Thu, 12 Jan 2017 19:47:59 GMT
 Content-Type: text/html; charset=ISO-8859-1
 Cache-Control: must-revalidate,no-cache,no-store
 Content-Length: 340

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