Arrays.equals()

　　我们知道判断字符串相等使用的是equals方法，那么要是判断两个字符串数组是否相等呢，要是char数组呢，同样的java.util.Arrays类提供了equals()方法，如下是官方API：

/**
     * Returns <tt>true</tt> if the two specified arrays of Objects are
     * <i>equal</i> to one another.  The two arrays are considered equal if
     * both arrays contain the same number of elements, and all corresponding
     * pairs of elements in the two arrays are equal.  Two objects <tt>e1</tt>
     * and <tt>e2</tt> are considered <i>equal</i> if <tt>(e1==null ? e2==null
     * : e1.equals(e2))</tt>.  In other words, the two arrays are equal if
     * they contain the same elements in the same order.  Also, two array
     * references are considered equal if both are <tt>null</tt>.<p>
     *
     * @param a one array to be tested for equality
     * @param a2 the other array to be tested for equality
     * @return <tt>true</tt> if the two arrays are equal
     */
    public static boolean equals(Object[] a, Object[] a2) {
        if (a==a2)
            return true;
        if (a==null || a2==null)
            return false;

int length = a.length;
        if (a2.length != length)
            return false;

for (int i=0; i<length; i++) {
            Object o1 = a[i];
            Object o2 = a2[i];
            if (!(o1==null ? o2==null : o1.equals(o2)))
                return false;
        }

return true;
    }

看看上面的红色部分，其实底层调用的还是Object 的equals方法