Some customizing exceptions need to be handled with customizing logic, such as creating a specific error.jsp in web applications. You can develop your own exception handler to implement your customized exception handling logic. After configuring in btt.xml, the customizing exception handler handles the exceptions from channel layer.

The toolkit initializes the customizing exception handler, where the customizing exception handling logic is defined to meet certain requirements. When the customizing exception is caught, the customizing exception handler will execute the predefined the logic at channel layer, such as switching to an error page in web application.