Object

/*jadclipse*/// Decompiled by Jad v1.5.8g. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://www.kpdus.com/jad.html
// Decompiler options: packimports(3) radix(10) lradix(10) 
// Source File Name:   Object.java

package java.lang;

// Referenced classes of package java.lang:
//            StringBuilder, IllegalArgumentException, CloneNotSupportedException, InterruptedException, 
//            Throwable, Class, Integer, String

public class Object
{

    public Object()
    {
    }

    private static native void registerNatives();

    public final native Class getClass();

    public native int hashCode();

    public boolean equals(Object obj)
    {
        return this == obj;
    }

    protected native Object clone()
        throws CloneNotSupportedException;

    public String toString()
    {
        return (new StringBuilder()).append(getClass().getName()).append("@").append(Integer.toHexString(hashCode())).toString();
    }

    public final native void notify();

    public final native void notifyAll();

    public final native void wait(long l)
        throws InterruptedException;

    public final void wait(long l, int i)
        throws InterruptedException
    {
        if(l < 0L)
            throw new IllegalArgumentException("timeout value is negative");
        if(i < 0 || i > 999999)
            throw new IllegalArgumentException("nanosecond timeout value out of range");
        if(i >= 500000 || i != 0 && l == 0L)
            l++;
        wait(l);
    }

    public final void wait()
        throws InterruptedException
    {
        wait(0L);
    }

    protected void finalize()
        throws Throwable
    {
    }

    static 
    {
        registerNatives();
    }
}


/*
	DECOMPILATION REPORT

	Decompiled from: D:\Java\JRE\lib\rt.jar
	Total time: 93 ms
	Jad reported messages/errors:
	Exit status: 0
	Caught exceptions:
*/

面试遇到问题。因为面试人不同，没遇到合适的而已。虽然我们经常用Object这个对象，但是我还真没太注意里面的方法。看看吧。