The Blas from Pas: JSF 2 Handling Unexpected Runtime Errors

Wednesday, 14 July 2010

JSF 2 Handling Unexpected Runtime Errors

Note for myself:

1. Create a managed bean as follows.

 
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

package oracle.jsf.demo.managedbeans;

import java.util.Map;
import javax.faces.bean.ManagedBean;
import javax.faces.context.FacesContext;

/**
*
* @author papicell
*/
@ManagedBean
public class ErrorBean
{
   private static final String BR = "n";

   public String getStackTrace()
   {
       FacesContext context = FacesContext.getCurrentInstance();
       Map map = context.getExternalContext().getRequestMap();
       Throwable throwable = (Throwable) map.get("javax.servlet.error.exception");
       StringBuilder builder = new StringBuilder();
       builder.append(throwable.getMessage()).append(BR);

       for (StackTraceElement element : throwable.getStackTrace())
       {
         builder.append(element).append(BR);
       }

       return builder.toString();
   }

}

2. Define error page in web.xml which will catch all unknown exceptions.

 
<error-page>
       <exception-type>java.lang.Exception</exception-type>
       <location>/pages/main/error.jsf</location>
</error-page>

3. Define error page Facelet error.xhtml as follows

 
<?xml version="1.0" encoding="UTF-8"?>
<!--
To change this template, choose Tools | Templates
and open the template in the editor.
-->
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<ui:composition
     xmlns="http://www.w3.org/1999/xhtml"
     xmlns:h="http://java.sun.com/jsf/html"
     xmlns:ui="http://java.sun.com/jsf/facelets"
     template="/pages/templates/EmpTemplate.xhtml"
     xmlns:f="http://java.sun.com/jsf/core">

   <ui:define name="title">
       #{msg.browserheading}
   </ui:define>

   <ui:define name="header">
       <h3 style="font-family: arial; font-variant: small-caps; color: #336699">
           You have encountered a system error!!
       </h3>
   </ui:define>

   <ui:define name="body">
       The error message is:
       <b>
           #{requestScope['javax.servlet.error.message']}
       </b>
       <p />
       <font color="RED">
           Please show the system administator the error below.
       </font>
       <p />
       <textarea rows="30" cols="100">
           <h:outputText escape="false" value="#{errorBean.stackTrace}"/>
       </textarea>
       <p />
   </ui:define>

   <ui:define name="footer">
       <ui:include src="/pages/employees/footer.xhtml" />
   </ui:define>

</ui:composition>

2 comments:

Dan said...: Thanks for simple and clean example.
I ned to know one thing that how to serialize Result.; Thursday, November 03, 2011 5:52:00 pm
Crystian said...: thanks you!; Saturday, November 12, 2011 8:33:00 am

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Wednesday, 14 July 2010

JSF 2 Handling Unexpected Runtime Errors

2 comments: