总结
public final native Class<?> getClass() //返回此 Object 运行时的类
public native int hashCode() //返回对象的哈希码
public boolean equals(Object obj) //判断其他对象与此对象是否“相等”
protected native Object clone() throws CloneNotSupportedException //创建并返回此对象的一个副本
public String toString() //返回对象的字符串表示
public final native void notify() //唤醒在此对象监视器上等待的单个线程
public final native void notifyAll() //唤醒在此对象监视器上等待的所有线程
public final native void wait(long timeout) throws InterruptedException //使当前对象的线程等待 timeout 时长
public final void wait(long timeout, int nanos) throws InterruptedException //使当前对象的线程等待 timeout 时长,或其他线程中断当前线程
public final void wait() throws InterruptedException //使当前对象的线程等待
protected void finalize() throws Throwable {} //垃圾回收时调用该方法