请问关于jsp和servlet 之间传递数据的问题

首先我创建了jsp设置了参数 submit后 转到servlet进行 servlet取得参数后一切正常 处理数据后想通过 javabean来传递数据 在servlet中已经设置ok 然后forward回原来的那个jsp 在其中使用jsp:useBean 的方法取参数 结果无论如何都没有办法取得 请问错在哪里 
另外也试过在servlet中
UserSession user = new UserSession();
user.setIsLogin(result);
user.setUserID(loginID);

request.setAttribute("userInf", user);
后 forward回原来的jsp 想调用javaBean中的值 会报错
org.apache.jasper.JasperException: Exception in JSP: /home.jsp:9188:        <%
89:        UserSession user = (UserSession)request.getAttribute("userInf");
90:        //if (loginInf.getIsLogin()== 1) {
91:        while (user.getIsLogin() == 1) {
92:        out.println("ok");
93:        }
94:        out.println("Hello " + (String)request.getAttribute("test") + " " + (String)request.getAttribute("test1")+ " " +UserS.getUserID()+ " " +UserS.getIsLogin());
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:506)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:395)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause java.lang.NullPointerException
org.apache.jsp.home_jsp._jspService(home_jsp.java:160)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)请问这个问题怎么解决阿 谢谢了