无法在JSP / Servlet中的请求中设置属性-Java？

Question

Here are the steps I follow in my jsps code: 1) login page and am posting it to servlet.

2) In the servlet, I am setting up some request attributes and forward the request using dispatcher to another to set bean property.

3) The bean set the property and forwards to a different url.

4) In this url, I pull the attributes from the request to display on page. I get a null out of the request, indicating that my attribute is not set on request. That is the displayinfo.jsp below displays Welcome Null . why the attribute is not set?

Here is my code: Login page:

<form id="login" method="post" action="setBeansAllPropertiesLoginUser.do">  
    <span>UserName:</span><input name="uid" type="text" style="width:250px;" /> 
    <span>Password:</span><input name="pwd" type="password" style="width:250px;"/>
</form>

servlet:

@WebServlet("/setBeansAllPropertiesLoginUser.do")
public class SetBeansAllPropertiesLoginuser extends HttpServlet {

    public SetBeansAllPropertiesLoginuser() {
        super();
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String uid = request.getParameter("uid");
        String pwd = request.getParameter("pwd");

        request.setAttribute("userId", uid);
        request.setAttribute("password", pwd);
        //verify login details
        int authLevel = 1;

        String base = "setBean.jsp";
        /*
        String params = String.format("?userId=%s&password=%s&authLevel=%d"
                , uid, pwd, authLevel);
        */
        String dest = String.format("%s%s"
                        ,base
                        ,params);
        //RequestDispatcher rd = request.getRequestDispatcher(dest);
        RequestDispatcher rd = request.getRequestDispatcher(base);
        rd.forward(request, response);
    }

}

setBean.jsp

<table style="width:100%;">
        <tr>
            <td style="width:25%;height:80%;" valign="top">
                <jsp:include page="navbar.jsp" />
            </td>
            <td style="width:75%;height:80%;">
                <jsp:useBean id="wu" class="com.worldmanager.models.WebUser"
                    scope="request">
                    <jsp:setProperty name="wu" property="*" />
                </jsp:useBean>

                <jsp:forward page="displayinfo.jsp" />
            </td>
        </tr>
    </table>

displayinfo.jsp :

<table style="width:100%;">
        <tr>
            <td style="width:25%;height:80%;" valign="top">
                <jsp:include page="navbar.jsp" />
            </td>
            <td style="width:75%;height:80%;">
                <jsp:useBean id="wu" class="com.worldmanager.models.WebUser" scope="request"/>

                <h1>Welcome 
                    <jsp:getProperty name="wu" property="userId" />
                </h1>
            </td>
        </tr>
    </table>

My bean is correct. I tested it. Above I pasted the code that is relevant. It is not complete code

Answer 1

Just change

<jsp:getProperty name="wu" property="userId" />

to

<c:out value="${userId}" />

to read it directly from request attribute

by using <jsp:getProperty> you are requesting wu.getUserId() and you haven't set wu 's property in available scope

Or

Set wu 's property explicitly

  <jsp:setProperty name="wu" property="userId"  value="${userId}"/>
  <jsp:setProperty name="wu" property="password"  value="${password}/>

and access it same way as you are doing now

  <jsp:getProperty name="wu" property="userId" />

Answer 2

According to this , the following notation

<jsp:setProperty name="wu" property="*" />

will retrieve and set properties based on request parameter names. So change your request parameters from

String uid = request.getParameter("uid");
String pwd = request.getParameter("pwd");

to

String uid = request.getParameter("userId");
String pwd = request.getParameter("password");

Obviously change your form 's input parameter names as well.