如何确保始终调用 finalize()(Java 练习中的思考)

Create a class with a finalize( ) method that prints a message. In main( ), create an object of your class. Modify the previous exercise so that your finalize( ) will always be called.

这是我写的代码:

public class Horse {
    boolean inStable;
    Horse(boolean in){
        inStable = in;
    }   
    public void finalize(){
        if (!inStable) System.out.print("Error: A horse is out of its stable!");
    }
}
public class MainWindow {
    public static void main(String[] args) {
        Horse h = new Horse(false);
        h = new Horse(true);
        System.gc();
    }
}

它创建一个新的 Horse 对象，布尔值 inStable 设置为 false.现在，在 finalize() 方法中，它检查 inStable 是否为 false.如果是，它会打印一条消息.