How to ensure singleton classes no longer exist

hi all not sure if this is the right forum....
I am writting an application that integrates another, I wish to stop and then restart the integrated application but it seems that the singleton classes of which there are quite a few ( each being statically initalised) do not disappear when I try to shut them dowm. (if I am shutting them down that is ...)
is there a way to ensure these instances are terminated so I can restart the integrated application inside my application?
is there a way to see what instances exist so I can see if in fact I am disposing of any?
thanks for ur help

is there a way to ensure these instances are
terminated so I can restart the integrated application
inside my application?
is there a way to see what instances exist so I can
see if in fact I am disposing of any?
What exactly are you trying to achieve?
Do these hold on to resources which you must clean first? Then you must have a clean/dispose method. There is no other option. You can use a registration class to make this easier.
Do you simply want to reinitialize them? Then you could use a class loader but it probably going to take less time to simply do the same as above and add a reinit method to each. Again you can use a registration class to make this easier.

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Tom wrote:
Hi ,
I tried implementing a singleton class , and then invoking the same in a filter class.
Both are then deployed as a web app (war file) in a managed server.
I created a similar app , deployed the same as another app in the same managed server .
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But am getting two instances of the singleton class in the two apps - not the same .Two apps = two instances.
Basically by definition.
>
I was under the impression that , a singleton is loaded in the class loader level , and since all apps under the same managed server used the same JVM , singleton will only get initialized once. A class is loaded by a class loader.
Any class loader that loads a class, by definition loads the class.
A VM can have many class loaders. And far as I know every JEE server in existance that anyone uses, uses class loaders.
And finally there might be a problem with the architecture/design of a JEE system which has two applications but which is trying to solve it with a singleton. That suggests a there might be concept problem with understanding what an "app" is in the first place.

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How to ensure singleton classes no longer exist

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