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Posted to users@tomcat.apache.org by Jason Novotny <JD...@lbl.gov> on 2001/02/12 01:11:17 UTC
errorpage.jsp: Can't convert javax.servlet.jsp.JspWriter to
java.io.PrintWriter
I've been learning JSP with this great book from manning.com and
I've been trying to write an error page. According to the book, I should
be able to do the following:
<%@ page isErrorPage="true"%>
<h1>The following error has been detected:</h1>
<b><%= exception %></b<br>
<% exception.printStackTrace(out); %>
However, when I try this I get the following:
gpdk/_0002fjsp_0002ferror_0002ejsperror_jsp_14.java:143: Incompatible
type for method. Can't convert javax.servlet.jsp.JspWriter to
java.io.PrintWriter.
exception.printStackTrace(out);
^
1 error
What's the secret to printing a stack trace to the page?
Thanks, Jason
--
Jason Novotny novotny@george.lbl.gov
Home: (510) 704-9917 Work: (510) 486-8662
NERSC Distributed Computing http://www-didc.lbl.gov
Re: errorpage.jsp: Can't convert javax.servlet.jsp.JspWriter to
java.io.PrintWriter
Posted by William Brogden <wb...@bga.com>.
Jason Novotny wrote:
>
> I've been learning JSP with this great book from manning.com and
> I've been trying to write an error page. According to the book, I should
> be able to do the following:
>
> <%@ page isErrorPage="true"%>
> <h1>The following error has been detected:</h1>
>
> <b><%= exception %></b<br>
>
> <% exception.printStackTrace(out); %>
>
> However, when I try this I get the following:
>
> gpdk/_0002fjsp_0002ferror_0002ejsperror_jsp_14.java:143: Incompatible
> type for method. Can't convert javax.servlet.jsp.JspWriter to
> java.io.PrintWriter.
> exception.printStackTrace(out);
> ^
> 1 error
>
> What's the secret to printing a stack trace to the page?
You can't cast the JspWriter to a PrintWriter so what you
have to do is create a StringWriter, use that to make a PrintWriter
and print the stack trace to it. Then just use the toString()
method of StringWriter to get a single string with the full trace.
--
WBB - wbrogden@lanw.com
Java Cert mock exams http://www.lanw.com/java/javacert/
Author of Java Developer's Guide to Servlets and JSP
ISBN 0-7821-2809-2
Re: errorpage.jsp: Can't convert javax.servlet.jsp.JspWriter to
java.io.PrintWriter
Posted by Chris Janicki <Ja...@ia-inc.com>.
I don't have time to test this, but I think the problem is not in the
stack trace, but the previous line. Try replacing it with:
<%= exception.getMessage() %>
I think the <%= %> expects a String or native.
FYI: A good way to learn/debug JSP is to look at the "*.java" file
created by the server. In your case, look at line 143 of
_0002fjsp_0002ferror_0002ejsperror_jsp_14.java
>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<
On 2/11/01, 7:11:17 PM, Jason Novotny <JD...@lbl.gov> wrote regarding
errorpage.jsp: Can't convert javax.servlet.jsp.JspWriter to
java.io.PrintWriter:
> I've been learning JSP with this great book from manning.com and
> I've been trying to write an error page. According to the book, I should
> be able to do the following:
> <%@ page isErrorPage="true"%>
> <h1>The following error has been detected:</h1>
> <b><%= exception %></b<br>
> <% exception.printStackTrace(out); %>
> However, when I try this I get the following:
> gpdk/_0002fjsp_0002ferror_0002ejsperror_jsp_14.java:143: Incompatible
> type for method. Can't convert javax.servlet.jsp.JspWriter to
> java.io.PrintWriter.
> exception.printStackTrace(out);
> ^
> 1 error
> What's the secret to printing a stack trace to the page?
> Thanks, Jason
> --
> Jason Novotny novotny@george.lbl.gov
> Home: (510) 704-9917 Work: (510) 486-8662
> NERSC Distributed Computing http://www-didc.lbl.gov
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, email: tomcat-user-help@jakarta.apache.org
Re: errorpage.jsp: Can't convert javax.servlet.jsp.JspWriter to java.io.PrintWriter
Posted by David Wall <dw...@myEastside.com>.
> <% exception.printStackTrace(new java.io.PrintWriter(out)); %>
Just consider that this should probably only be used on a test/development
system since presenting stack traces to site visitors is probably not a
grand idea.
David
Re: errorpage.jsp: Can't convert javax.servlet.jsp.JspWriter to
java.io.PrintWriter
Posted by Gilles Laborderie <gx...@careersite.com>.
The error message tells you that it's trying to convert "out" from
JspWriter to a PrintWriter which is the type expected from
printStackTrace.
Try:
<% exception.printStackTrace(new java.io.PrintWriter(out)); %>
This will creates a new PrintWriter from the existing "out"
Gilles
On Sun, 11 Feb 2001, Jason Novotny wrote:
>
> I've been learning JSP with this great book from manning.com and
> I've been trying to write an error page. According to the book, I should
> be able to do the following:
>
>
> <%@ page isErrorPage="true"%>
> <h1>The following error has been detected:</h1>
>
> <b><%= exception %></b<br>
>
> <% exception.printStackTrace(out); %>
>
> However, when I try this I get the following:
>
> gpdk/_0002fjsp_0002ferror_0002ejsperror_jsp_14.java:143: Incompatible
> type for method. Can't convert javax.servlet.jsp.JspWriter to
> java.io.PrintWriter.
> exception.printStackTrace(out);
> ^
> 1 error
>
>
> What's the secret to printing a stack trace to the page?
>
> Thanks, Jason
>
>
>
> --
> Jason Novotny novotny@george.lbl.gov
> Home: (510) 704-9917 Work: (510) 486-8662
> NERSC Distributed Computing http://www-didc.lbl.gov
>
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, email: tomcat-user-help@jakarta.apache.org
>
--
Gilles Laborderie
---------------------------------------------
CareerSite.com
gxl@careersite.com