Object方法

Object方法就是在Object類中定義的方法，在接口中不允許爲Object方法提供缺省實現。

Object類定義如下：

public class Object {

    private static native void registerNatives();
    static {
        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 getClass().getName() + "@" + Integer.toHexString(hashCode());
    }

   
    public final native void notify();

   
    public final native void notifyAll();

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

    
    public final void wait(long timeout, int nanos) throws InterruptedException {
        if (timeout < 0) {
            throw new IllegalArgumentException("timeout value is negative");
        }

        if (nanos < 0 || nanos > 999999) {
            throw new IllegalArgumentException(
                                "nanosecond timeout value out of range");
        }

        if (nanos >= 500000 || (nanos != 0 && timeout == 0)) {
            timeout++;
        }

        wait(timeout);
    }

  
    public final void wait() throws InterruptedException {
        wait(0);
    }
    protected void finalize() throws Throwable { }
}