As with the SAX and DOM factory classes, one exception handles requested — but unsupported — features, and another exception handles instantiation errors.

For transparent switch over, applications can be coded to catch the StaleConnection exception and retry a specified number of times to obtain new connection handles.

This code is included in the code which handles the click event for the Invoke Service button and its purpose is to avoid a null pointer exception when the web service is invoked with an empty string.