[C#,Java,PHP] IMAP文件夹名称编码和解码方法

[C#] 来源：http://www.oschina.net/code/snippet_110991_2237

// 编码
private string IMAPEncode(string folder)
{
   string rtn = "", base64;
   int index = 0;
   Regex regAsis = new Regex(@"\G(?:[\x20-\x25\x27-\x7e])+");
   Regex reg26 = new Regex(@"\G&");
   Regex regEncode = new Regex(@"\G(?:[^\x20-\x7e])+");
   Regex regEq = new Regex(@"=+$");
   Regex regSlash = new Regex(@"\/");
   while (index < folder.Length) {
      Match m;
      m = regAsis.Match(folder, index);
      if(m.Success)
      {
         index = index + m.Length;
         rtn = rtn + m.Value;
         continue;
      }
      m = reg26.Match(folder, index);
      if(m.Success)
      {
         index = index + m.Length;
         rtn = rtn + "&-";
         continue;
      }
      m = regEncode.Match(folder, index);
      if(m.Success)
      {
         index = index + m.Length;
         base64 = Convert.ToBase64String(Encoding.GetEncoding("UTF-16BE").GetBytes(m.Value));
         base64 = regEq.Replace(base64, "");
         base64 = regSlash.Replace(base64, ",");
         rtn = rtn + "&" + base64 + "-";
         continue;
      }
   }
   return rtn;
}

// 解码
private string IMAPDeconde(string folder)
{
   string rtn = "", base64;
   int index = 0;
   Regex regAsis = new Regex(@"\G([^&]+)");
   Regex reg26 = new Regex(@"\G\&-");
   Regex regDecode = new Regex(@"\G\&([A-Za-z0-9+,]+)-?");
   Regex regComma = new Regex(@",");
   while (index < folder.Length) {
      Match m;
      m = regAsis.Match(folder, index);
      if(m.Success)
      {
         index = index + m.Length;
         rtn = rtn + m.Value;
         continue;
      }
      m = reg26.Match(folder, index);
      if(m.Success)
      {
         index = index + m.Length;
         rtn = rtn + "&";
         continue;
      }
      m = regDecode.Match(folder, index);
      if(m.Success)
      {
         index = index + m.Length;
         base64 = m.Value.Substring(1, m.Value.Length - 2);
         base64 = regComma.Replace(base64, "/");
         int mod = base64.Length % 4;
         if(mod > 0 ) base64 = base64.PadRight(base64.Length + (4 - mod), '=');
         base64 = Encoding.GetEncoding("UTF-16BE").GetString(Convert.FromBase64String(base64));
         rtn = rtn + base64;
         continue;
      }
   }
   return rtn;
}

[Java] 来源：http://grandboy.iteye.com/blog/908887

// 编码
public class ImapFolderEncoder {
    public static String encode(String folder) {
    String rtn = "", base64;
    int index = 0;
    Pattern regAsis = Pattern.compile("\\G(?:[\\x20-\\x25\\x27-\\x7e])+");
    Pattern reg26 = Pattern.compile("\\G&");
    Pattern regEncode = Pattern.compile("\\G(?:[^\\x20-\\x7e])+");
    Pattern regEq = Pattern.compile("=+$");
    Pattern regSlash = Pattern.compile("\\/");
    while (index < folder.length()) {
        Matcher m;
        m = regAsis.matcher(folder);
        if (m.find(index)) {
        index = index + (m.end() - m.start());
        rtn = rtn + m.group();
        continue;
        }
        m = reg26.matcher(folder);
        if (m.find(index)) {
        index = index + (m.end() - m.start());
        rtn = rtn + "&-";
        continue;
        }
        m = regEncode.matcher(folder);
        if (m.find(index)) {
        index = index + (m.end() - m.start());
        base64 = SimpleUtil.encodeBase64Content(m.group(), "UTF-16BE");
        base64 = base64.replaceAll(regEq.pattern(), "");
        base64 = base64.replaceAll(regSlash.pattern(), ",");
        rtn = rtn + "&" + base64 + "-";
        continue;
        }
    }
    return rtn;
    }
    
}

// 解码
public class ImapFolderDecoder {
    public static String decode(String folder) {
    String rtn = "", base64;
    int index = 0;
    Pattern regAsis = Pattern.compile("\\G([^&]+)");
    Pattern reg26 = Pattern.compile("\\G\\&-");
    Pattern regDecode = Pattern.compile("\\G\\&([A-Za-z0-9+,]+)-?");
    Pattern regComma = Pattern.compile(",");
    while (index < folder.length()) {
        Matcher m;
        m = regAsis.matcher(folder);
        if (m.find(index)) {
        index = index + (m.end() - m.start());
        rtn = rtn + m.group();
        continue;
        }
        m = reg26.matcher(folder);
        if (m.find(index)) {
        index = index + (m.end() - m.start());
        rtn = rtn + "&";
        continue;
        }
        m = regDecode.matcher(folder);
        if (m.find(index)) {
        index = index + (m.end() - m.start());
        base64 = m.group().substring(1, m.group().length() - 1);
        base64 = base64.replaceAll(regComma.pattern(), "/");
        int mod = base64.length() % 4;
        int count = 4 - mod;
        while (count > 0) {
            base64 += "=";
            count--;
        }
        base64 = SimpleUtil.base64Decode(base64, "UTF-16BE");
        rtn = rtn + base64;
        continue;
        }
    }
    return rtn;
    }
}

[PHP] 来源：从上面C#的代码翻译过来

// 编码
function IMAPEncode($sStr)
{
    $sOut = '';
    $sBase64 = '';
    $nIndex = 0;
    $sRegAsis = '/^(?:[\x20-\x25\x27-\x7e])+/';
    $sReg26 = '/^&/';
    $sRegEncode = '/^(?:[^\x20-\x7e])+/';
    $sRegEq = '/=+$/';
    $sRegSlash = '/\//';

    while ($nIndex < strlen($sStr))
    {
        $aTmp = array();
        $nResult = preg_match($sRegAsis, $sStr, &$aTmp, null, $nIndex);
        if ($nResult)
        {
            $nIndex += strlen($aTmp[0]);
            $sOut .= $aTmp[0];
            continue;
        }
        $nResult = preg_match($sReg26, $sStr, &$aTmp, null, $nIndex);
        if ($nResult)
        {
            $nIndex += strlen($aTmp[0]);
            $sOut .= '&-';
            continue;
        }
        $nResult = preg_match($sRegEncode, $sStr, &$aTmp, null, $nIndex);
        if ($nResult)
        {
            $nIndex += strlen($aTmp[0]);
            $sBase64 = base64_encode(iconv('UTF-8', 'UTF-16BE', $aTmp[0]));
            $sBase64 = preg_replace($sRegEq, '', $sBase64);
            $sBase64 = preg_replace($sRegSlash, ',', $sBase64);
            $sOut .= '&' . $sBase64 . '-';
            continue;
        }
    }
    return $sOut;
}

// 解码
function IMAPDeconde($sStr)
{
    $sOut = '';
    $sBase64 = '';
    $nIndex = 0;
    $sRegAsis = '/^([^&]+)/';
    $sReg26 = '/^\&-/';
    $sRegDecode = '/^\&([A-Za-z0-9+,]+)-?/';
    $sRegComma = '/,/';

    while ($nIndex < strlen($sStr))
    {
        $aTmp = array();
        $nResult = preg_match($sRegAsis, $sStr, &$aTmp, null, $nIndex);
        if ($nResult)
        {
            $nIndex += strlen($aTmp[0]);
            $sOut .= $aTmp[0];
            continue;
        }
        $nResult = preg_match($sReg26, $sStr, &$aTmp, null, $nIndex);
        if ($nResult)
        {
            $nIndex += strlen($aTmp[0]);
            $sOut .= '&';
            continue;
        }
        $nResult = preg_match($sRegDecode, $sStr, &$aTmp, null, $nIndex);
        if ($nResult)
        {
            $nIndex += strlen($aTmp[0]);
            $sBase64 = substr($aTmp[0], 1, strlen($aTmp[0]) - 2);
            $sBase64 = preg_replace($sRegComma, '/', $sBase64);
            $nMod = strlen($sBase64) % 4;
            if ($nMod > 0) $sBase64 .= str_repeat('=', 4 - $nMod);
            $sBase64 = iconv('UTF-16BE', 'UTF-8', base64_decode($sBase64));
            $sOut .= $sBase64;
            continue;
        }
    }
    return $sOut;
}