jsp servlet exception: bean not found within scope.

Question

I'm getting this error:

javax.servlet.ServletException: bean givingFormBean not found within scope

on a page with this at the top.

<jsp:useBean id="givingFormBean" scope="request" type="olc.onlinegiving.servlets.BuiltForm"/>

The class exists in the classpath, it worked this morning, and I don't get what not found within scope means.

I've googled and googled and nothing useful came up.

Answer 1

You must add

<jsp:useBean id="givingFormBean" type="some.packg.GivingForm" scope="request" />

Because by default the bean is looked on the page scope

Answer 2

You need the class attribute instead of the type attribute.

The following:

<jsp:useBean id="bean" type="com.example.Bean" scope="request" />

does basically the following behind the scenes:

Bean bean = (Bean) pageContext.getAttribute("bean", PageContext.REQUEST_SCOPE);
if (bean == null) {
    throw new ServletException("bean not found within scope");
}
// Use bean ...

While the following:

<jsp:useBean id="bean" class="com.example.Bean" scope="request" />

does basically the following behind the scenes:

Bean bean = (Bean) pageContext.getAttribute("bean", PageContext.REQUEST_SCOPE);
if (bean == null) {
    bean = new Bean();
    pageContext.setAttribute("bean", bean, PageContext.REQUEST_SCOPE);
}
// Use bean ...

If it has worked before and it didn't work "in a sudden", then it means that something which is responsible for putting the bean in the scope has stopped working. For example a servlet which does the following in the doGet():

request.setAttribute("bean", new Bean());
request.getRequestDispatcher("page.jsp").forward(request, response);

Maybe you've invoked the JSP page directly by URL instead of invoking the Servlet by URL. If you'd like to disable direct access to JSP pages, then put them in /WEB-INF and forward to it instead.

Answer 3

Fantastic BalusC ! i also got this problem. Your soln works, more than that your explanation is very useful. Thank you !