The implicit object ‘exception‘ is not available to all JSP pages. The ‘exception’ object is available only to JSP error pages. JSP error pages are pages to which processing is forwarded when an exception is thrown from another JSP page. The implicit ‘exception’ object represents the uncaught exception that was thrown from another JSP page and that resulted in this error page being invoked.

The exception object is accessible only from the JSP error page instance to which processing was forwarded when the exception was encountered. JSP page can be marked as an error page by setting the attribute of the page directive ‘isErrorPage‘ to ‘true‘.