variantsupport.java

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    /**
     * <p>Turns a codepage number into the equivalent character encoding's 
     * name.</p>
     *
     * @param codepage The codepage number
     * 
     * @return The character encoding's name. If the codepage number is 65001, 
     * the encoding name is "UTF-8". All other positive numbers are mapped to
     * "cp" followed by the number, e.g. if the codepage number is 1252 the 
     * returned character encoding name will be "cp1252".
     * 
     * @exception UnsupportedEncodingException if the specified codepage is
     * less than zero.
     */
    public static String codepageToEncoding(final int codepage)
    throws UnsupportedEncodingException
    {
        if (codepage <= 0)
            throw new UnsupportedEncodingException
                ("Codepage number may not be " + codepage);
        switch (codepage)
        {
            case Constants.CP_UTF16:
                return "UTF-16";
            case Constants.CP_UTF16_BE:
                return "UTF-16BE";
            case Constants.CP_UTF8:
                return "UTF-8";
            case Constants.CP_037:
                return "cp037";
            case Constants.CP_GBK:
                return "GBK";
            case Constants.CP_MS949:
                return "ms949";
            case Constants.CP_WINDOWS_1250:
                return "windows-1250";
            case Constants.CP_WINDOWS_1251:
                return "windows-1251";
            case Constants.CP_WINDOWS_1252:
                return "windows-1252";
            case Constants.CP_WINDOWS_1253:
                return "windows-1253";
            case Constants.CP_WINDOWS_1254:
                return "windows-1254";
            case Constants.CP_WINDOWS_1255:
                return "windows-1255";
            case Constants.CP_WINDOWS_1256:
                return "windows-1256";
            case Constants.CP_WINDOWS_1257:
                return "windows-1257";
            case Constants.CP_WINDOWS_1258:
                return "windows-1258";
            case Constants.CP_JOHAB:
                return "johab";
            case Constants.CP_MAC_ROMAN:
                return "MacRoman";
            case Constants.CP_MAC_JAPAN:
                return "SJIS";
            case Constants.CP_MAC_CHINESE_TRADITIONAL:
                return "Big5";
            case Constants.CP_MAC_KOREAN:
                return "EUC-KR";
            case Constants.CP_MAC_ARABIC:
                return "MacArabic";
            case Constants.CP_MAC_HEBREW:
                return "MacHebrew";
            case Constants.CP_MAC_GREEK:
                return "MacGreek";
            case Constants.CP_MAC_CYRILLIC:
                return "MacCyrillic";
            case Constants.CP_MAC_CHINESE_SIMPLE:
                return "EUC_CN";
            case Constants.CP_MAC_ROMANIA:
                return "MacRomania";
            case Constants.CP_MAC_UKRAINE:
                return "MacUkraine";
            case Constants.CP_MAC_THAI:
                return "MacThai";
            case Constants.CP_MAC_CENTRAL_EUROPE:
                return "MacCentralEurope";
            case Constants.CP_MAC_ICELAND:
                  return "MacIceland";
            case Constants.CP_MAC_TURKISH:
                return "MacTurkish";
            case Constants.CP_MAC_CROATIAN:
                return "MacCroatian";
            case Constants.CP_US_ACSII:
            case Constants.CP_US_ASCII2:
                return "US-ASCII";
            case Constants.CP_KOI8_R:
                return "KOI8-R";
            case Constants.CP_ISO_8859_1:
                return "ISO-8859-1";
            case Constants.CP_ISO_8859_2:
                return "ISO-8859-2";
            case Constants.CP_ISO_8859_3:
                return "ISO-8859-3";
            case Constants.CP_ISO_8859_4:
                return "ISO-8859-4";
            case Constants.CP_ISO_8859_5:
                return "ISO-8859-5";
            case Constants.CP_ISO_8859_6:
                return "ISO-8859-6";
            case Constants.CP_ISO_8859_7:
                return "ISO-8859-7";
            case Constants.CP_ISO_8859_8:
                return "ISO-8859-8";
            case Constants.CP_ISO_8859_9:
                return "ISO-8859-9";
            case Constants.CP_ISO_2022_JP1:
            case Constants.CP_ISO_2022_JP2:
            case Constants.CP_ISO_2022_JP3:
                return "ISO-2022-JP";
            case Constants.CP_ISO_2022_KR:
                return "ISO-2022-KR";
            case Constants.CP_EUC_JP:
                return "EUC-JP";
            case Constants.CP_EUC_KR:
                return "EUC-KR";
            case Constants.CP_GB2312:
                return "GB2312";
            case Constants.CP_GB18030:
                return "GB18030";
            case Constants.CP_SJIS:
                return "SJIS";
            default:
                return "cp" + codepage;
        }
    }


    /**
     * <p>Writes a variant value to an output stream. This method ensures that
     * always a multiple of 4 bytes is written.</p>
     *
     * <p>If the codepage is UTF-16, which is encouraged, strings
     * <strong>must</strong> always be written as {@link Variant#VT_LPWSTR}
     * strings, not as {@link Variant#VT_LPSTR} strings. This method ensure this
     * by converting strings appropriately, if needed.</p>
     *
     * @param out The stream to write the value to.
     * @param type The variant's type.
     * @param value The variant's value.
     * @param codepage The codepage to use to write non-wide strings
     * @return The number of entities that have been written. In many cases an
     * "entity" is a byte but this is not always the case.
     * @exception IOException if an I/O exceptions occurs
     * @exception WritingNotSupportedException if a property is to be written
     * who's variant type HPSF does not yet support
     */
    public static int write(final OutputStream out, final long type,
                            final Object value, final int codepage)
        throws IOException, WritingNotSupportedException
    {
        int length = 0;
        switch ((int) type)
        {
            case Variant.VT_BOOL:
            {
                int trueOrFalse;
                if (((Boolean) value).booleanValue())
                    trueOrFalse = 1;
                else
                    trueOrFalse = 0;
                length = TypeWriter.writeUIntToStream(out, trueOrFalse);
                break;
            }
            case Variant.VT_LPSTR:
            {
                final byte[] bytes =
                    (codepage == -1 ?
                    ((String) value).getBytes() :
                    ((String) value).getBytes(codepageToEncoding(codepage)));
                length = TypeWriter.writeUIntToStream(out, bytes.length + 1);
                final byte[] b = new byte[bytes.length + 1];
                System.arraycopy(bytes, 0, b, 0, bytes.length);
                b[b.length - 1] = 0x00;
                out.write(b);
                length += b.length;
                break;
            }
            case Variant.VT_LPWSTR:
            {
                final int nrOfChars = ((String) value).length() + 1; 
                length += TypeWriter.writeUIntToStream(out, nrOfChars);
                char[] s = Util.pad4((String) value);
                for (int i = 0; i < s.length; i++)
                {
                    final int high = ((s[i] & 0x0000ff00) >> 8);
                    final int low = (s[i] & 0x000000ff);
                    final byte highb = (byte) high;
                    final byte lowb = (byte) low;
                    out.write(lowb);
                    out.write(highb);
                    length += 2;
                }
                out.write(0x00);
                out.write(0x00);
                length += 2;
                break;
            }
            case Variant.VT_CF:
            {
                final byte[] b = (byte[]) value; 
                out.write(b);
                length = b.length;
                break;
            }
            case Variant.VT_EMPTY:
            {
                TypeWriter.writeUIntToStream(out, Variant.VT_EMPTY);
                length = LittleEndianConsts.INT_SIZE;
                break;
            }
            case Variant.VT_I2:
            {
                TypeWriter.writeToStream(out, ((Integer) value).shortValue());
                length = LittleEndianConsts.SHORT_SIZE;
                break;
            }
            case Variant.VT_I4:
            {
                if (!(value instanceof Integer))
                {
                    throw new ClassCastException("Could not cast an object to "
                            + Integer.class.toString() + ": "
                            + value.getClass().toString() + ", "
                            + value.toString());
                }
                length += TypeWriter.writeToStream(out, 
                          ((Integer) value).intValue());
                break;
            }
            case Variant.VT_I8:
            {
                TypeWriter.writeToStream(out, ((Long) value).longValue());
                length = LittleEndianConsts.LONG_SIZE;
                break;
            }
            case Variant.VT_R8:
            {
                length += TypeWriter.writeToStream(out, 
                          ((Double) value).doubleValue());
                break;
            }
            case Variant.VT_FILETIME:
            {
                long filetime = Util.dateToFileTime((Date) value);
                int high = (int) ((filetime >> 32) & 0x00000000FFFFFFFFL);
                int low = (int) (filetime & 0x00000000FFFFFFFFL);
                length += TypeWriter.writeUIntToStream
                    (out, 0x0000000FFFFFFFFL & low);
                length += TypeWriter.writeUIntToStream
                    (out, 0x0000000FFFFFFFFL & high);
                break;
            }
            default:
            {
                /* The variant type is not supported yet. However, if the value
                 * is a byte array we can write it nevertheless. */
                if (value instanceof byte[])
                {
                    final byte[] b = (byte[]) value; 
                    out.write(b);
                    length = b.length;
                    writeUnsupportedTypeMessage
                        (new WritingNotSupportedException(type, value));
                }
                else
                    throw new WritingNotSupportedException(type, value);
                break;
            }
        }

        return length;
    }

}