使用finalize让对象涅槃重生

详情参见代码：

package com.imooc.web;
import sun.misc.GC;

import javax.sound.midi.Track;
import java.awt.print.Book;

/**
 * Copyright (C), 2002-2019
 * FileName: TerminationCondition
 * <p>
 * Description:
 *
 * @author 如果这段代码非常棒就是梁子松写的
 * 如果这代码挺差劲那么我也不知道是谁写的
 * @version 1.0.0
 * @create 19-7-6 下午10:07
 */

public class TerminationCondition {

    private static TerminationCondition book = null;

    boolean aBoolean;

    public TerminationCondition(boolean aBoolean) {
        this.aBoolean = aBoolean;
    }

    public static void main(String[] args) throws InterruptedException {
        //初始化
        book = new TerminationCondition(true);
        //取消引用
        book = null;
        //清理
        System.gc();
        //确保被清理
        Thread.sleep(500);
        //因为有finalize方法所以对象会重生
        if (null != book) { //此时对象应该处于(reachable, finalized)状态
            System.out.println("Yes , I am still alive");
        } else {
            System.out.println("No , I am dead");
        }
        //再次取消引用
        book = null;
        //调用gc
        System.gc();
        //确保被清理
        Thread.sleep(500);
        //因为之前已经调用过finalize方法了所以对象已经被清理
        if (null != book) {
            System.out.println("Yes , I am still alive");
        } else {
            System.out.println("No , I am dead");
        }
    }

    @Override
    protected void finalize() throws Throwable {
        super.finalize();
        System.out.println("execute method finalize()");
        book = this;
    }
}

输出

execute method finalize()
Yes , I am still alive
No , I am dead