java garbage collect

I use jvc(just-in-time) compile my program, and use jview to run it.
can I forbid garbage collect to happen until program run out of memory.
I put one System.gc in different place in my program, why does it cost very different runing time in the same program(9 class).
 
yijunAsked:
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russgoldCommented:
You cannot generally control garbage collection in a system with automatic garbage collection (AG), such as Java.  This is one reason many people don't like AG in real-time systems.  The behavior is simply not predictable.

The normal behavior for most Java VM's is to delay all gc activity until it runs out of memory - or Runtime.gc() is called.
You can take advantage of this fact by adding calls to Runtime.gc() at various non-time-critical points in your system to ensure that a large backlog of unreferenced objects never develops.  Your behavior will still not be entirely predictable, but it should never get to be a problem.
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yijunAuthor Commented:
Hi, thanks!
But how to delay gc happen until using out of memory?
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