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Editorial Team
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Asked: 2026-05-20T04:57:22+00:00

user is null in servlet. Pls let me if doing mistake. i m trying

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user is null in servlet. Pls let me if doing mistake.

i m trying to get all html element in bean rateCode.jsp

<%@page import="com.hermes.data.RateCode_" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
    <head>
        <title>Rate Code</title>
    </head>
    <body>      
         <jsp:useBean id="user" class="com.hermes.data.RateCode_" scope="request" >
            <jsp:setProperty name="user" property="*"/></jsp:useBean>
            <form  id="f_rateCode" action="/ratePromoCodes" method="post"  >
                <table align="center" border="1" cellspacing="0">
                    <tr>
                        <td colspan="2" align="center" class="header">Rate Code Administrations</td>
                    </tr>
                    <tr>
                        <td align="right" style="border-style: solid;">Rate Code:</td>
                        <td align="left" style="border-style: solid;">
                            <input type="text" id="code" name="code" value="${user.code}"  size="10" maxlength="32" style="width: 100px"/>
                    </td>
                </tr>

                <tr>
                    <td align="right" style="border-style: solid;">Rate Description:</td>
                    <td align="left" style="border-style: solid;">
                        <input type="text" id="description" name="description" value="<%=user.getDescription()%>" maxlength="128" size="40"></td>
                </tr>              
                <tr><td><input type="submit" value="ok" /></td> </tr>
            </table>
        </form>

Servlet – ratePromoCodes

protected void doPost(HttpServletRequest req, HttpServletResponse resp) {
        RateCode_ rc = (RateCode_) req.getAttribute("user");
        Enumeration an = req.getAttributeNames();
        Enumeration pn = req.getParameterNames();
        Object o = null;
        while (an.hasMoreElements()) {
            o = an.nextElement();
            System.out.println(o);
        }
        while (pn.hasMoreElements()) {
            o = pn.nextElement();
            System.out.println(o);
        }
    }

RateCode.java (javaBean)

public class RateCode_  {    
    private String code ;
    private String description;
    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}
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1 Answer

  1. Editorial Team

    You seem to misunderstand the working and purpose of jsp:useBean.

    First of all, you’ve declared the bean to be in the session scope and you’re filling it with all parameters of the current request.

    <jsp:useBean id="user" class="com.hermes.data.RateCode_" scope="session">
    <jsp:setProperty name="user" property="*"/>
</jsp:useBean>

    This bean is thus stored as session attribute with the name user. You need to retrieve it in the servlet as session attribute, not as request attribute.

    RateCode_ user = (RateCode_) request.getSession().getAttribute("user");

    (user is a terrible and confusing attribute name by the way, I’d rename it rateCode or something, without this odd _ in the end)

    However, it’ll contain nothing. The getCode() and getDescription() will return null. The <jsp:setProperty> has namely not filled it with all request parameters yet at that point you’re attempting to access it in the servlet. It will only do that when you forward the request containing the parameters back to the JSP page. However this takes place beyond the business logic in the servlet.

    You need to gather them as request parameters yourself. First get rid of whole <jsp:useBean> thing in the JSP and do as follows in the servlet’s doPost() method:

    RateCode_ user = new RateCode_();
user.setCode(request.getParameter("code"));
user.setDescription(request.getParameter("description"));
// ...
request.setAttribute("user", user); // Do NOT store in session unless really necessary.

    and then you can access it in the JSP as below:

    <input type="text" name="code" value="${user.code}" />
<input type="text" name="description" value="${user.description}" />

    (this is only sensitive to XSS attacks, you’d like to install JSTL and use fn:escapeXml)

    No, you do not need <jsp:useBean> in JSP. Keep it out, it has practically no value when you’re using the MVC (level 2) approach with real servlets. The <jsp:useBean> is only useful for MV design (MVC level 1). To save boilerplate code of collecting request parameters, consider using a MVC framework or Apache Commons BeanUtils. See also below links for hints.

    See also:

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