//: c04:Garbage.java // From Thinking in Java, 2nd Edition // Available at http://www.BruceEckel.com // (c) Bruce Eckel 1999 // Copyright notice in Copyright.txt // Demonstration of the garbage // collector and finalization class Chair { static boolean gcrun = false; static boolean f = false; static int created = 0; static int finalized = 0; int i; Chair() { i = ++created; if(created == 47) System.out.println("Created 47"); } protected void finalize() { if(!gcrun) { gcrun = true; System.out.println( "Beginning to finalize after " + created + " Chairs have been created"); } if(i == 47) { System.out.println( "Finalizing Chair #47, " + "Setting flag to stop Chair creation"); f = true; } finalized++; if(finalized >= created) System.out.println( "All " + finalized + " finalized"); } } public class Garbage { public static void main(String[] args) { if(args.length == 0) { System.err.println("Usage: \n" + "java Garbage before\n or:\n" + "java Garbage after"); return; } while(!Chair.f) { new Chair(); new String("To take up space"); } System.out.println( "After all Chairs have been created:\n" + "total created = " + Chair.created + ", total finalized = " + Chair.finalized); if(args[0].equals("before")) { System.out.println("gc():"); System.gc(); System.out.println("runFinalization():"); System.runFinalization(); } System.out.println("bye!"); if(args[0].equals("after")) System.runFinalizersOnExit(true); } } ///:~