src/org/nutz/lang/Strings.java
public static String removeFirst(CharSequence str) {
        if (str == null)
            return null;
        if (str.length() > 1)
            return str.subSequence(1, str.length()).toString();
        return "";
    }
public static String removeFirst(CharSequence str) {
        if (str == null)
            return null;
        if (str.length() > 1)
            return str.subSequence(1, str.length()).toString();
        return "";
    }
截去第一个字符
<p>
比如:
<ul>
<li>removeFirst("12345") => 2345
<li>removeFirst("A") => ""
</ul>

@param str
字符串
@return 新字符串