finalize()函数调用问题

[sunliwen780502]

//: 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);
}
} ///:~

finalize()函数是什么时候被调用的？
如果我采用下面的方法执行。
java Garbage
而不指定命令行参数。我觉得finalize()函数不应该执行。可是它却执行了，请问
这是为什么呢？

[rainwxj]

thik in JAVA中讲：垃圾回收时间是不确定的，所以finalize()函数执行也是不确定的！

[killme2008]

永远不要指望finalize()来做任何操作

[blackpark]

无法得知JVM何时运行finalize方法，
但你可以使用System.gc();强制执行finalize()方法。

[sunliwen780502]

楼上的朋友们：
程序的输出为：
Created 47
Beginning to finalize after 3486 Chairs have been created
Finalizing Chair #47, Setting flag to stop Chair creation
After all Chairs have been created:
total created = 3881, toal finalized = 2684
bye!

显然finalize()函数已经被调用了，是在我不指定命令行参数的情况下调用的。
请各位解释一下啊，我初次接触java,谢谢！！！！