垃圾收集Java中的静态变量

Question

I am running one Java process in Unix machine. If I want to stop the application, I am simply killing the process using shell script.

Here is my question:

How static variables are garbage collected after killing the process ?

Do i require to set each static variable to null to claim back the memory or JVM itself do immediately ?

Answer 1

If you are on a unix box, and force a thread dump (kill -3), it should force garbage collection.

Static variables are referenced by Class objects which are referenced by ClassLoaders -so, when the classloders become elligible for collection, your static variables will follow suit.

Assigning null to an object or System.gc() doesn't start garbage collection, they just signal eligibility for garbage collection. Killing the process returns the entire java heap to the system.

Answer 2

When a process is killed, the entire java heap is returned to the system; there is no need for the JVM to garbage collect at this point.

Answer 3

Java will itself do the garbage collection. Even if you set it to null you cannot force the JVM to do the garbage collection.

Answer 4

Java application is run over JVM which is an other application which runs over OS. Killing an application means killing JVM itself,after than OS will deallocate the memory occupied by JVM, in other words java application.