Ask Michael Webinar every second Wednesday

Question

Hello everyone
You may know me as the answerer of questions in this forum and as the author of the Discoverer 10g Handbook. I wanted to let you know that I also conduct a free Ask Michael webinar on Discoverer every second Wednesday of the month at 3pm Central. There is no fee for this and I am not selling anything nor am I touting for business. This is just a way for me to provide another free way to help the Discoverer community by passing on my knowledge.
If you would like to know more click here: http://ascbi.com/question.htm
By the way, I am also presenting a paper on maximizing investment in Discoverer at the IOUG / OAUG Collaborate conference in Orlando in May, and again at the ODTUG conference in Monterey in June. If you happen to be attending come along and say hello.
You may also be interested in reading Oracle's statement of direction for Discoverer which you will find here: http://www.oracle.com/technology/products/discoverer/pdf/discoverer_sod_jan2009.pdf
Best wishes
Michael Armstrong-Smith

Answer 1

The goal with singletons is to ensure that at least one thread has a reference to the object that you do not want finalized. In this case, the class is being garbage-collected and reloaded. In your main, you can do this:
public static void main(String [] argv)
     Class cl = LogManager.class;
}and assuming that main terminates when your app does, that will protect the class from being garbage collected. If your application is based in a thread, then do the same thing in your run() method. It isn't evident in your code how the log manager is exposed - if the functionality is used by calling static methods on the class (I.E., the instances are never shared) then the problem can be fixed as above. If you do share the instance, then it is a race condition as to when the problem will arise.