java 垃圾回收的陷阱~

//: Garbage.java
// 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);
	}
} // /:~