Question

我正在尝试使用POST方法将数据从我的Android应用程序发送到servlet但是servlet没有显示任何类型的活动，只是在输出中显示了null。虽然我正在使用GET方法从Android应用程序上的servlet接收响应。我们尝试在logcat上打印动作。它显示数据已发送但在浏览器上显示为null。我也收到异常“无效使用单客户端连接管理器：仍然分配连接”

Android代码： -

String url = "http://10.0.2.2:8084/AndroidApp/AndroidServlet";

DefaultHttpClient httpClient = new DefaultHttpClient();
ResponseHandler<String> res = new BasicResponseHandler();
HttpPost httpPost = new HttpPost(url);

try {

List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();

nameValuePairs.add(new BasicNameValuePair("Name", name));
nameValuePairs.add(new BasicNameValuePair("Father", father));
nameValuePairs.add(new BasicNameValuePair("Gender", gender));

    httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
    HttpResponse httpResponse = httpClient.execute(httpPost);
    String response = httpClient.execute(httpPost, res);
}

Servlet代码： -

public class AndroidServlet extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException, ClassNotFoundException, SQLException {

    String Name=request.getParameter("Name");
    String Father=request.getParameter("Father");
    String Gender=request.getParameter("Gender");

     try (PrintWriter out = response.getWriter()) {
        out.println("Hello Android !!!!");
        out.println( Name  + " " +  Father + " "  +  Gender + " ");

    }
}

浏览器输出： -

Hello Android !!!!
null null null

Answer 1

在没有外部工具的情况下调试网络应用程序很困难，当然如果不编译它就很难找到代码中的错误。
为了调试这些应用程序，我使用Android Emulator + WireShark来查看HTTP请求的主体。希望它会有所帮助。

编辑：

ResponseHandler<String> responseHandler = new BasicResponseHandler();
        try{
            String strResponseSaveGoal =
                    httpclient.execute(httppost, responseHandler);
            Log.d("sendCancelOrderRequest", strResponseSaveGoal);
        }catch ( ConnectTimeoutException conEx )
        {
            handler.sendEmptyMessage(CANCEL_REQUEST_ERROR);
        }
        catch (ClientProtocolException ex) {
            Log.d("sendCancelOrderRequest","");
            handler.sendEmptyMessage(CANCEL_REQUEST_ERROR);
        }catch (IOException ex) {
            Log.d("sendCancelOrderRequest","");
            handler.sendEmptyMessage(CANCEL_REQUEST_ERROR);
        }

从Android上接收servlet上的数据？

1 个答案: