public static String removeTitle(String str ,int pos, int len)
    {
        if(pos <= -1) return str;
        
        StringBuilder sb = new StringBuilder();
        char[] strs = str.toCharArray();
        int index = 0;//不包含分隔符的index
        for(int i=0;i<strs.length;i++)
        {
            if(strs[i] != split_char)
            {
                ++index;
            }
            if(index > pos && index <= pos + len)
            {
                continue;
            }
            sb.append(strs[i]);
        }
        return sb.toString();
    }