System.gc() 和System.runFinalization()
The ? Java ? language ? provides ? some ? built-in ? routines ? for ? controlling ? garbage ? collection: ? the ? methods ? System.gc() ? and ? System.runFinalization(). ? System.gc() ? requests ? that ? garbage ? collection ? be ? run. ? System.runFinalizers() ? asks ? that ? finalizers ? be ? executed, ? but ? that ? memory ? is ? not ? necessarily ? freed.
