关于Interger和Long的hashCode

    /**
     * Returns a hash code for this <code>Integer</code>.
     *
     * @return  a hash code value for this object, equal to the 
     *          primitive <code>int</code> value represented by this 
     *          <code>Integer</code> object. 
     */
    public int hashCode() {
	return value;
    }

 

    /**
     * Returns a hash code for this <code>Long</code>. The result is
     * the exclusive OR of the two halves of the primitive
     * <code>long</code> value held by this <code>Long</code>
     * object. That is, the hashcode is the value of the expression:
     * <blockquote><pre>
     * (int)(this.longValue()^(this.longValue()&gt;&gt;&gt;32))
     * </pre></blockquote>
     *
     * @return  a hash code value for this object.
     */
    public int hashCode() {
	return (int)(value ^ (value >>> 32));
    }