What is the exact purpose of calling System.exit() in java

java object garbage-collection jvm systemexit
maXfenda picture maXfenda · Aug 12, 2013 · Viewed 7.6k times · Source

I am in a little bit confusion with system.exit. I founded some things about from this link.

but I have some doubts in my mind. If I use system exit, what will happened to the created objects,variable and ect. Are everything get destroyed once I called system.exit? If "Yes" then why we force to the garbage collection before system.exit() ? If "No" how long the created objects are stored in the JVM (memory)? If run the program again after exit from system, what will happened to the previous objects if they not destroyed once I called System.exit();?

Thanks.

Answer

Peter Lawrey picture Peter Lawrey · Aug 12, 2013

If I use system exit, what will happened to the created objects,variable and ect. Are everything get destroyed once I called system.exit?

Only user threads are destroyed by a System exit.

why we force to the garbage collection before system.exit() ?

We don't and it wouldn't be very useful as this might not do anything.

how long the created objects are stored in the JVM (memory)?

Until they are no longer needed and a clean up occurs, of the JVM really exits

If run the program again after exit from system, what will happened to the previous objects if they not destroyed once I called System.exit();?

They are destroyed when the program finishes. In any case, every program gets it's own new set of variables even if run multiple times. There is no sharing of variables between programs.

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