unreliability

Making a reliable web service unreliable, but in a controlled way?

I have a Java 6 based web service client using the standard Java 6 annotation based approach (i.e. no Axis or other third party web service library), which works very well. So does the web service I am calling, which is nice, but now I need to write error handling code, and I need to be able to make the existing web service unreliable i...