public class FullAjaxExceptionHandler extends ExceptionHandlerWrapper
FullAjaxExceptionHandlerFactory to see how to set this up.
This exception handler will parse the web.xml and web-fragment.xml files to find the error
page locations of the HTTP error code 500 and all declared specific exception types. Those locations
need to point to Facelets files (JSP is not supported). The location of the HTTP error code 500 or the
exception type java.lang.Throwable is required in order to get the full ajax exception handler to work,
because there's then at least a fall back error page whenever there's no match with any of the declared specific
exceptions. So, you must at least have either
<error-page> <error-code>500</error-code> <location>/errors/500.xhtml</location> </error-page>
or
<error-page> <exception-type>java.lang.Throwable</exception-type> <location>/errors/500.xhtml</location> </error-page>
You can have both, but the java.lang.Throwable one will always get precedence over the 500
one, as per the Servlet API specification, so the 500 one would be basically superfluous.
The exception detail is available in the request scope by the standard Servlet error request attributes like as in a normal synchronous error page response. You could for example show them in the error page as follows:
<ul>
<li>Date/time: #{of:formatDate(now, 'yyyy-MM-dd HH:mm:ss')}</li>
<li>User agent: #{header['user-agent']}</li>
<li>User IP: #{request.remoteAddr}</li>
<li>Request URI: #{requestScope['javax.servlet.error.request_uri']}</li>
<li>Ajax request: #{facesContext.partialViewContext.ajaxRequest ? 'Yes' : 'No'}</li>
<li>Status code: #{requestScope['javax.servlet.error.status_code']}</li>
<li>Exception type: #{requestScope['javax.servlet.error.exception_type']}</li>
<li>Exception message: #{requestScope['javax.servlet.error.message']}</li>
<li>Stack trace:
<pre>#{of:printStackTrace(requestScope['javax.servlet.error.exception'])}</pre>
</li>
</ul>
Exceptions during render response can only be handled when the javax.faces.FACELETS_BUFFER_SIZE is
large enough so that the so far rendered response until the occurrence of the exception fits in there and can
therefore safely be resetted. When rendering of the error page itself fails due to a bug in the error page itself
and the response can still be resetted, then a hardcoded message will be returned informing the developer about the
double mistake.
If more fine grained control is desired for determining the root cause of the caught exception, or whether it should
be handled, or determining the error page, or logging the exception, then the developer can opt to extend this
FullAjaxExceptionHandler and override one or more of the following methods:
FullAjaxExceptionHandlerFactory| Constructor and Description |
|---|
FullAjaxExceptionHandler(ExceptionHandler wrapped)
Construct a new ajax exception handler around the given wrapped exception handler.
|
| Modifier and Type | Method and Description |
|---|---|
protected String |
findErrorPageLocation(FacesContext context,
Throwable exception)
Determine the error page location based on the given exception.
|
protected Throwable |
findExceptionRootCause(FacesContext context,
Throwable exception)
Determine the root cause based on the caught exception, which will then be used to find the error page location.
|
ExceptionHandler |
getWrapped() |
void |
handle()
Handle the ajax exception as follows, only and only if the current request is an ajax request with an uncommitted
response and there is at least one unhandled exception:
Find the root cause of the exception by
findExceptionRootCause(FacesContext, Throwable). |
protected void |
logException(FacesContext context,
Throwable exception,
String location,
String message,
Object... parameters)
Log the thrown exception and determined error page location with the given message, optionally parameterized
with the given parameters.
|
protected boolean |
shouldHandleExceptionRootCause(FacesContext context,
Throwable exception)
Returns
true if the FullAjaxExceptionHandler should handle this exception root cause. |
getHandledExceptionQueuedEvent, getHandledExceptionQueuedEvents, getRootCause, getUnhandledExceptionQueuedEvents, isListenerForSource, processEventpublic FullAjaxExceptionHandler(ExceptionHandler wrapped)
wrapped - The wrapped exception handler.public void handle()
throws FacesException
findExceptionRootCause(FacesContext, Throwable).
findErrorPageLocation(FacesContext, Throwable).
handle in class ExceptionHandlerWrapperFacesExceptionprotected Throwable findExceptionRootCause(FacesContext context, Throwable exception)
Exceptions.unwrap(Throwable).context - The involved faces context.exception - The caught exception to determine the root cause for.protected boolean shouldHandleExceptionRootCause(FacesContext context, Throwable exception)
true if the FullAjaxExceptionHandler should handle this exception root cause. If
this returns false, then the FullAjaxExceptionHandler will skip handling this exception and
delegate it further to the wrapped exception handler. The default implementation just returns true.context - The involved faces context.exception - The caught exception to determine the root cause for.true if the given exception should be handled by the FullAjaxExceptionHandler.protected String findErrorPageLocation(FacesContext context, Throwable exception)
WebXml.findErrorPageLocation(Throwable).context - The involved faces context.exception - The exception to determine the error page for./ and be relative to the context path.protected void logException(FacesContext context, Throwable exception, String location, String message, Object... parameters)
java.util.logging as SEVERE.context - The involved faces context.exception - The exception to log.location - The error page location.message - The log message.parameters - The log message parameters, if any.public ExceptionHandler getWrapped()
getWrapped in interface FacesWrapper<ExceptionHandler>getWrapped in class ExceptionHandlerWrapper