Exception Handling - using an error page

[Kurt Boets]

Hello,

I am trying to assure correct exception handling; depending on the exception, the user is forwared to an error page.
I did develop a Filter class, an ErrorAwareRequestWrapper class that wraps the http error codes.
When I do a deploy (on a BEA Weblogic 8.1) I receive an error.
Hereby I will show you my :

The Filter class.

The ErrorAwareRequestWrapper class

The web.xml file

The stack trace of the exception thrown by the server

  
class ErrorHandlerFilter implements Filter {
 
    /* 
     * @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
     */
    public void init(FilterConfig arg0) throws ServletException {
        System.out.println("*******ENTERING THE ERROR HANDLER FILTER");
    }
 
    
    /* 
     * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
     */
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse,
            FilterChain filterChain) throws IOException, ServletException {
        System.out.println("ENTERING the doFilter of ErrorhandlerFilter");
 
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        
        if (!(response instanceof ErrorAwareRequestWrapper)) {
            response = new ErrorAwareRequestWrapper(response);
        }
 
        filterChain.doFilter(servletRequest, response);
 

    }
 
    /* 
     * @see javax.servlet.Filter#destroy()
     */   
    public void destroy() {
        
 
    }

  
public class ErrorAwareRequestWrapper extends HttpServletResponseWrapper {
    
    /**
     * Default Constructor. 
     * @param httpServletResponse
     */
    public ErrorAwareRequestWrapper(HttpServletResponse httpServletResponse) {
        super(httpServletResponse);
        System.out.println("*** ENTERING THE CONSTRUCTOR OF ERROR AWAREREQUEST WRAPPER");
    }
 
    /**
     * Intercepting the errorCode and determing the kind of error using
     * the errorCode.    
     * @param errorCode - The error status code 
     * @throws IOException
     */
    public void sendError(int errorCode) throws IOException {
        System.out.println("ENTERING THE SENDERROR:" +errorCode);
        if (errorCode == HttpServletResponse.SC_INTERNAL_SERVER_ERROR){
            System.out.println("INTERNAL SERVER ERROR OCCURED WITH ERROR AWAREREQUEST WRAPPER");
            throw new RuntimeException();
        }
        
        super.sendError(errorCode);
    }
}

  
<!-- Error Filter -->
 
<filter>
<filter-name>errorHandlerFilter</filter-name>   <filter-class>packagename.ErrorHandlerFilter</filter-class> 
</filter>
<filter-mapping>
 <filter-name>errorHandlerFilter</filter-name>
 <url-pattern>/*</url-pattern>        
</filter-mapping>
 
<!-- Error pages definition -->
<error-page>
 <exception-type>java.lang.RuntimeException</exception-type>
 <location>/error.jsf</location>
</error-page> 

 
<26-May-2005 14:05:38 o'clock CEST> <Error> <HTTP> <BEA-101165> <Could not load user defined filter in we
b.xml: ServletContext(id=24958637,name=) ErrorHandlerFilter.
java.lang.IllegalAccessException: Class weblogic.servlet.internal.WebAppServletContext can not access a m
ember of class packagename.ErrorHandlerFilter with modifiers ""
        at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:57)
        at java.lang.Class.newInstance0(Class.java:302)
        at java.lang.Class.newInstance(Class.java:261)
        at weblogic.servlet.internal.WebAppServletContext.registerFilter(WebAppServletContext.java:2980)
        at weblogic.servlet.internal.WebAppServletContext.initFilters(WebAppServletContext.java:2956)
        at weblogic.servlet.internal.WebAppServletContext.preloadResources(WebAppServletContext.java:3257
)
        at weblogic.servlet.internal.WebAppServletContext.setStarted(WebAppServletContext.java:5949)
        at weblogic.servlet.internal.WebAppModule.start(WebAppModule.java:862)
        at weblogic.j2ee.J2EEApplicationContainer.start(J2EEApplicationContainer.java:2127)
        at weblogic.j2ee.J2EEApplicationContainer.activate(J2EEApplicationContainer.java:2168)
        at weblogic.management.deploy.slave.SlaveDeployer$ComponentActivateTask.activateContainer(SlaveDe
ployer.java:2503)

Has anyone yet expercience with handling exceptions using error pages or
filters ?
All help is welcome.
Thx,

[Varun Khanna]

Try to make your ErrorHandlerFilter class "public"

[Kurt Boets]

Indeed, it works now.
Thx,

[Dinesh Gupta]

Hi,

This a very useful post. I want to implement same type of filter.
I am using JSF and Struts tiles component.
The problem is that sendError method of the ErrorAwareRequestWrapper is not called.

If anyone have idea, Please reply.