将某个字符串的首字母进行大小写转换

主要是熟悉对character的用法

public static String toLowerCaseFirstOne(String s)
    {
        if(Character.isLowerCase(s.charAt(0)))
            return s;
        else
            return (new StringBuilder()).append(Character.toLowerCase(s.charAt(0))).append(s.substring(1)).toString();
    }

    public static String toUpperCaseFirstOne(String s)
    {
        if(Character.isUpperCase(s.charAt(0)))
            return s;
        else
            return (new StringBuilder()).append(Character.toUpperCase(s.charAt(0))).append(s.substring(1)).toString();
    }