How do I print the stack trace?

[tomstrummer.tomstrummer.gmail.com]

So hopefully this will be an easy one --

I want to print out the exception details on my error.xhml page.  So I need access to the original exception.  Using this page as a reference, I thought I could add a bit in my error.xhtml like so:

<h:inputTextarea styleClass='stackTrace' value='#{errorHandler.stackTrace}' />

And then have a backing Seam bean:

@Name("errorHandler") @Scope(ScopeType.PAGE)
public class ErrorHandlerImpl implements ErrorHandler {

     //@In("org.jboss.seam.handledException")
     @In("org.jboss.seam.exception")
     private Exception error;  
     
     @Override
     public String getStackTrace() {
          ByteArrayOutputStream out = new ByteArrayOutputStream();
          error.printStackTrace( new PrintStream(out,true) );
          error = null;
          return out.toString();
     }
}

But whenever this gets called, I get the @In attribute requires non-null value -- the bijected field (error) is always null. 

Likewise, if I try to access the exception or handledException straight from my template, I get a similar error:

<h:inputTextarea styleClass='stackTrace' value='#{org.jboss.seam.exception.message}' />

Produces:

javax.el.PropertyNotFoundException: /error.xhtml @32,92 value="#{org.jboss.seam.exception.message}": Property 'message' not found on type org.jboss.seam.Namespace

What am I doing wrong?  Do I have to eschew Seam's error handling and resort to something similar to how MyFaces handles errors?

Thanks in advance.

[jimk1723]

Hm. I added this code to my error.xhtml and ginned up a bogus RuntimeException in one of my action handlers. It worked fine.

  <h:outputText value="org.jboss.seam.exception.class = #{org.jboss.seam.exception.class}" />
  <hr/>

  <h:outputText value="org.jboss.seam.handledException.class = #{org.jboss.seam.handledException.class}" />
  <hr/>

  <h:outputText value="org.jboss.seam.exception.message = #{org.jboss.seam.exception.message}" />
  <hr/>

  <h:outputText value="org.jboss.seam.handledException = #{org.jboss.seam.handledException}" />
  <hr/>

  <h:outputText value="org.jboss.seam.exception.rootCause = #{org.jboss.seam.exception.rootCause}" />
  <hr/>

  <ol>
   <ui:repeat var="ex" value="#{org.jboss.seam.exception.rootCause.stackTrace}">
    <li>
     <h:outputText value="#{ex.className}:#{ex.lineNumber} #{ex.methodName}" />
    </li>
   </ui:repeat>
  </ol>

I'm assuming you've disabled Facelets development mode and Seam debug mode. What exception are you throwing from your application and what does your pages.xml look like?

[gavin.king]

Eeek, thats a bug in Seam2, my fault. We have a package named org.jboss.seam.exception, and we also try to use that as the name for the exception. We need to change that context variable name (to  org.jboss.seam.exception.caughtException, I suggest). I'll create an issue in JIRA.

[gavin.king]

The issue is here

[amit.u.purohit]

Hi,
I am getting the same issue as Tom while using Seam managed exception handling. Following jsf component (in my error page)
<h:outputText value="org.jboss.seam.handledException.stacktrace = #{org.jboss.seam.handledException,stacktrace}" />
  <hr/>

prints the exception stacktrace when I redirect the user to the error page in case of any exception thrown in my application. However, when I try to refresh this error page, I get a property not found error for handlexception on
or.jboss.seam.Namespace.

I looked at the issue raised in jira, but there seems to be no resolution for the same.

Can you suggest me some other manner in which I can use features provided by Seam to print the exception stack trace and other information on my error page ?

Any help really appreciated