decode.java

手机邮箱撒的方式方式方式的

        } else if (lower.startsWith("=?iso-8859-1?q?")) {
            return decodeQuotedPrintable(s.substring(15, s.length() - 2), BodyPart.CH_ISO88591);
        } else if (lower.startsWith("=?iso-8859-2?q?")) {
            return decodeQuotedPrintable(s.substring(15, s.length() - 2), BodyPart.CH_ISO88592);
        } else if (lower.startsWith("=?utf-8?q?")) {
            return decodeQuotedPrintable(s.substring(10, s.length() - 2), BodyPart.CH_UTF8);
        } // base64 encoding
        else if (lower.startsWith("=?windows-1250?b?")) {
            return decodeBase64(s.substring(17, s.length() - 2), BodyPart.CH_WIN1250);
        } else if (lower.startsWith("=?iso-8859-1?b?")) {
            return decodeBase64(s.substring(15, s.length() - 2), BodyPart.CH_ISO88591);
        } else if (lower.startsWith("=?iso-8859-2?b?")) {
            return decodeBase64(s.substring(15, s.length() - 2), BodyPart.CH_ISO88592);
        } else if (lower.startsWith("=?utf-8?b?") ) {
            //return  decodeBase64(s.substring(10,s.length()-2), MessageHeader.CH_UTF8);
            return decodeBase64(s.substring(10, s.length() - 2), BodyPart.CH_UTF8);
        }
        return s;
    }

    /**
     * Decodes quoted header field (mostly a SUBJECT nad RECIPIENTS).
     * @param s Message header entry. line from message header. ( Subject:=?windows-1250?q?Alf?=)
     * @return original header entry where vakue sting was decoded (Subject:alf)
     */
    public static String decodeHeaderField(String s) throws MyException {
        int beginQuoted;
        int endQuoted;
        String begin, middle, end;
        beginQuoted = s.indexOf("=?");

        if (beginQuoted == -1) {
            return s;
        } else {
            endQuoted = s.indexOf("?", beginQuoted + 2);
            endQuoted = s.indexOf("?", endQuoted + 1);
            endQuoted = s.indexOf("?=", endQuoted + 1) + 2;
            begin = s.substring(0, beginQuoted);
            try {
                middle = decodeQuotedOrBinary(s.substring(beginQuoted, endQuoted));
            } catch (Exception ex) {
                throw new MyException(MyException.VARIOUS_DECODE_ILLEGAL_MIME);
            }
            end = decodeHeaderField(s.substring(endQuoted));
            return begin + middle + end;
        }
    }

    /** 
     * Encodes header value to into standartized mail format.
     * @param input Plain text value representation
     * @return string in utf-8 encoding stored in base64 with header
     */
    public static String encodeHeaderField(String input) {
        if (input.length() == 0) {
            return input;
        }
        return "=?UTF-8?B?" + toBase64(input, false) + "?=";
    }

    /**
     * Encodes an input string into base64 format. It means, that only 64 characters are needed to encode the text string.
     * @author <a href="http://izhuk.com">Igor Zhukovsky</a>
     * @param input string to convert to base64
     * @param isFile set to true if input is raw file data, false if input is text to be convert to utf-8
     */
    public static String toBase64(String input, boolean isFile) {
          if (DEBUG) { System.out.println("DEBUG Decode.toBase64(input=\"" + input + "\", isFile=" + isFile + ")"); }
        byte inData[] = null;
        if (isFile) {
            inData = new byte[ input.length()];
                  for (int l = 0; l < input.length(); l++) {
                inData[l] = (byte)input.charAt(l);
            }
        } else {
            try {
                // Not file, standard stirng
                inData = input.getBytes("utf-8");
            } catch (UnsupportedEncodingException ex) {
                ex.printStackTrace();
		// if exception is created converting to utf-8 (meaning it is likely
		// not available, use naive text conversion before converting to base64
                for (int l = 0; l < input.length(); l++) {
                    inData[l] = (byte)input.charAt(l);
                }
            }
        }
        
        String base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
        char output[] = new char[4];
        int state = 1;
        int restbits = 0;
        int chunks = 0;

        StringBuffer encoded = new StringBuffer();

        for (int i = 0; i < inData.length; i++) {
            int ic = inData[i] & 0xFF;
            switch (state) {
                case 1:
                    output[0] = base64.charAt(ic >>> 2);
                    restbits = ic & 0x03;
                    break;
                case 2:
                    output[1] = base64.charAt((restbits << 4) | (ic >>> 4));
                    restbits = ic & 0x0F;
                    break;
                case 3:
                    output[2] = base64.charAt((restbits << 2) | (ic >>> 6));
                    output[3] = base64.charAt(ic & 0x3F);
                    encoded.append(output);

                    // keep no more the 76 character per line
                    chunks++;
                    if ((chunks % 19) == 0) {
                        encoded.append("\r\n");
                    }
                    break;
            }
            state = (state < 3 ? state + 1 : 1);
        } // for

        /* final */
        switch (state) {
            case 2:
                output[1] = base64.charAt((restbits << 4));
                output[2] = output[3] = '=';
                encoded.append(output);
                break;
            case 3:
                output[2] = base64.charAt((restbits << 2));
                output[3] = '=';
                encoded.append(output);
                break;
        }

          if (DEBUG) { System.out.println("DEBUG Decode.toBase64 result=\"" + encoded + "\""); }
        return encoded.toString();
    }

    /**
     * Does a base64 decoding for a single character.
     * @return 6bit number reprezented by this char if base64 encoded
     * <p>
     * Contains code from Stefan Haustein's KObjects library (www.kobjects.org)
     * used by permission.
     */
    private static int decode(char c) throws MyException {
        //System.out.println("char= " + c);
        if (c >= 'A' && c <= 'Z') {
            return ((int) c) - 65;
        } else if (c >= 'a' && c <= 'z') {
            return ((int) c) - 97 + 26;
        } else if (c >= '0' && c <= '9') {
            return ((int) c) - 48 + 26 + 26;
        } else {
            switch (c) {
                case '+':
                    return 62;
                case '/':
                    return 63;
                case '=':
                    return 0;
                default:
                    throw new MyException(MyException.VARIOUS_DECODE_ILLEGAL_MIME);
            }
        }
    }

    /**
     * Decodes a <code>String</code> that is encoded in the Base64 encoding. If there occures an illegel
     * Base64 character, then a <code>MyException</code> with an appropriate message is thrown. This method
     * serves to encode a header fields.
     * @param s an encoded input header field.
     * @param charset a charset of the header field.
     */
    public static String decodeBase64(String s, byte charset) throws MyException {
        StringBuffer buff = new StringBuffer();
        int i = 0;
        int len = s.length(), b;

        while (true) {
            while (i < len && s.charAt(i) <= ' ') {
                i++;
            }

            if (i + 3 >= len) {
                break;
            }
            int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12) + (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3)));

            for (int j = 16; j >= 0; j -= 8) {
                if (j == 8 && s.charAt(i + 2) == '=') {
                    break;
                }
                if (j == 0 && s.charAt(i + 3) == '=') {
                    break;
                }
                b = (tri >> j) & 255;
                buff.append((char) b);
            }
            i += 4;
        }

        return convertCharSet(buff, charset).toString();
    }
    
    /**
     * Decodes a <code>String</code> that is encoded in the Base64 encoding. If there occures an illegel
     * Base64 character, then a <code>MyException</code> with a propriete message is thrown.
     */
    public static ByteArrayOutputStream decodeBase64(String s) throws MyException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        int i = 0;
        int len = s.length(), b;

        while (true) {
            while (i < len && s.charAt(i) <= ' ') {
                i++;
            }

            if (i + 3 >= len) {
                break;
            }
            int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12) + (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3)));

            for (int j = 16; j >= 0; j -= 8) {
                if (j == 8 && s.charAt(i + 2) == '=') {
                    break;
                }
                if (j == 0 && s.charAt(i + 3) == '=') {
                    break;
                }
                b = (tri >> j) & 255;
                bos.write((char) b);
            }
            i += 4;
        }
	return bos;
    }
}