将值从一个servlet传递到另一个servlet'；不能使用android应用程序

我的应用程序中有两个servlet。第一个servlet包含一个

post

方法，第二个servlet包含一个

get

方法。第一个servlet将用户名传递给第二个servlet。我正在使用

httpsession

传递对象。当我从我电脑上的邮递员应用程序中调用时，一切正常，但当我从android应用程序调用时，它显示空对象

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    GetUserTran cp = new GetUserTran();
    //cp.setBoId((String)request.getAttribute("boId"));
    HttpSession session = request.getSession();
    String urname = (String) session.getAttribute("userId");
    System.out.println(urname);

这是我的密码： 第一个servlet：

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    String userName,password;
    userName=request.getParameter("userName").toString();
    password=request.getParameter("password").toString
    HttpSession session = request.getSession();
            session.setAttribute("userId",userName);
            RequestDispatcher rd=request.getRequestDispatcher("/another servlet");
            rd.forward(request,response);
            }

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    GetUserTran cp = new GetUserTran();
    //cp.setBoId((String)request.getAttribute("boId"));
    HttpSession session = request.getSession();
    String urname = (String) session.getAttribute("userId");
    System.out.println(urname);

第二个Servlet：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    GetUserTran cp = new GetUserTran();
    //cp.setBoId((String)request.getAttribute("boId"));
    HttpSession session = request.getSession();
    String urname = (String) session.getAttribute("userId");
    System.out.println(urname);

---

}

请发布一些带有解释的代码。我已经添加了一个代码，发布了相关的android代码和LogCat？请发布一些带有解释的代码。我已经添加了一个代码，发布了相关的android代码和LogCat？

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    GetUserTran cp = new GetUserTran();
    //cp.setBoId((String)request.getAttribute("boId"));
    HttpSession session = request.getSession();
    String urname = (String) session.getAttribute("userId");
    System.out.println(urname);