Look at the line:
jsp.f_00025rm._0002fjsp_0002fform_0002fForm_0002ejspForm_jsp_0._jspService(_
0002fjsp_0002fform_0002fForm_0002ejspForm_jsp_0.java:122)
THIS is where your error occurred. Tomcat compiled your JSP page into the
named java file. Look in your tomcat\work directory for this file. It will
be in a folder named for your context. Look at line 122 in that file and
see where it found a problem. You can usually tell from that what you did
wrong.
I only worked with JRUN for a short while, but I seem to remember that it
was much nicer than Tomcat in this one respect, giving you the line number
back into your .jsp file instead of making you dig through the java file.
-----Original Message-----
From: Kenneth Litwak [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, August 15, 2001 3:35 PM
To: [EMAIL PROTECTED]
Subject: Newbie help needed: error running JSP
I just ran my first JSP that uses a form and got an
error. Unfortunately, the stack trace doesn't tell me
where in the JSP the error occured (that I can tell)
or where in my helper bean the problem ight be. I'd
heard that JSPs are hard to debug, and now I see why.
The JSP engine is not very helpful with what's wrong.
Here's the stack trace, followed by the JSP code.
Location: /examples/jsp/form/Form.jsp
Internal Servlet Error:
org.apache.jasper.JasperException: Attempted a bean
operation on a null object.
at
org.apache.jasper.runtime.JspRuntimeLibrary.handleGetProperty(JspRuntimeLibr
ary.java:424)
at
jsp.f_00025rm._0002fjsp_0002fform_0002fForm_0002ejspForm_jsp_0._jspService(_
0002fjsp_0002fform_0002fForm_0002ejspForm_jsp_0.java:122)
at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.ja
va:177)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:318)
at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:391)
at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at
org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404)
at
org.apache.tomcat.core.Handler.service(Handler.java:286)
at
org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
at
org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:79
7)
at
org.apache.tomcat.core.ContextManager.service(ContextManager.java:743)
at
org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpC
onnectionHandler.java:210)
at
org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
at
org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498)
at java.lang.Thread.run(Thread.java:484)
JSP code:
<html>
<body bgcolor="#c8d8f8">
<form action="/examples/jsp/form/Form.jsp"
method=post>
<center>
<table cellpadding=4 cellspacing=2 border=0>
<th bgcolor="#CCCCFF" colspan=2>
<font size=5>User Registration</font>
</th>
<tr>
<td valign=top>
<b>First Name</b>
<br>
<input type="text" name="firstName" size=15></td>
<td valign=top>
<b>Last Name</b>
<br>
<input type="text" name="lastName" size=15></td>
</tr>
<tr>
<td valign=top colspan=2>
<b>E-Mail</b>
<br>
<input type="text" name="email" size=20>
<br></td>
</tr>
<tr>
<td valign=top colspan=2>
<b>What languages do you program in?</b>
<br>
<input type="checkbox" name="languages"
value="Java">Java
<input type="checkbox" name="languages"
value="C++">C++
<input type="checkbox" name="languages"
value="C">C<br>
<input type="checkbox" name="languages"
value="Perl">Perl
<input type="checkbox" name="languages"
value="COBOL">COBOL
<input type="checkbox" name="languages"
value="VB">VB<br>
</td>
</tr>
<tr>
<td valign=top colspan=2>
<b>How often can we notify you regarding your
interests?</b>
<br>
<input type="radio" name="notify" value="Weekly"
checked>Weekly
<input type="radio" name="notify"
value="Monthly">Monthly
<input type="radio" name="notify"
value="Quarterly">Quarterly
<br></td>
</tr>
<tr>
<td align=center colspan=2>
<input type="submit" value="Submit"> <input
type="reset" value="Reset">
</td>
</tr>
</table>
</center>
</form>
<%-- Create the bean only when the form is posted --%>
<%
if (request.getMethod().equals("POST"))
{
%>
<jsp:useBean id="formHandler"
class="com.shopping.FormBean">
<%-- provide a setProperty tag and ensure that the
setter methods are invoked via introspection
--%>
<jsp:setProperty name="formHandler" property="*"/>
</jsp:useBean>
<p>
<hr>
<font color=red>
<b>You submitted:<P>
First Name:</b><br>
<%-- invoke the getter method to display the firstName
using the getProperty tag --%>
<jsp:getProperty name="formHandler"
property="firstName"/><br>
<br><b>Last Name:</b><br>
<%-- invoke the getter method to display the lastName
using the getProperty tag --%>
<jsp:getProperty name="formhandler"
property="lastName"/><br>
<br><b>Email:</b><br>
<%-- invoke the getter method to display the email
address using the getProperty tag
<jsp:getProperty name="formHandler"
property="email"/><br>
--%>
<b>Languages:</b><br>
<%
String[] lang = formHandler.getLanguages();
if (!lang[0].equals("1"))
{
out.println("<ul>");
for (int i=0; i<lang.length; i++)
out.println("<li>"+lang[i]);
out.println("</ul>");
}
else out.println("Nothing was selected<br>");
%>
<b>Notification:</b><br>
<%-- invoke the getter method to display the
notification status using the getProperty tag
--%>
<jsp:getProperty name="formHandler"
property="notify"/><br>
<br>
<%
}
%>
</font>
</body>
</html>
I think this would be better as an attachment but lots
of mailing lists don't like those, so ugly or not,
there it is. Thanks.
Ken
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