public static String formatOutput(String str)
    {
        //处理边界的分隔符
        int index = str.length()-1;
        int start = str.charAt(0) == split_char ? 1 : 0;
        int length = str.charAt(index) == split_char ? index : index + 1;
        if(start == 0 || length == index)
        {
            str = str.substring(start, length);
        }
        //格式化输出
        if(str.length()>0)
        {
            return "\""+str.replace(",", "\",\"")+"\"";
        }
        return null;
    }