记录几个比较特别的
1、protected Object clone() throws CloneNotSupportedException
其中官方文档中有一句：The class Object does not itself implement the interface Cloneable, so calling the clone method on an object whose class is Object will result in throwing an exception at run time.
大体意思是：使用clone()前提是该对象须实现Cloneable接口，否则报CloneNotSupportException异常
2、public final void notify()
参考官网文档可能看得有点晕，建议看看《Java线程锁，synchronized、wait、notify详解》
原文：https://www.cnblogs.com/wochenjun/p/10649139.html