private static void addCharacterSet(int value, String encodingName)
{
var eci = new CharacterSetECI(value, encodingName);
VALUE_TO_ECI[value] = eci; // can't use valueOf
NAME_TO_ECI[encodingName] = eci;
}
/// <summary>
/// returns the encoding object fo the specified charset
/// </summary>
/// <param name="charsetECI"></param>
/// <returns></returns>
public static System.Text.Encoding getEncoding(CharacterSetECI charsetECI)
{
if (charsetECI == null)
{
return(null);
}
return(getEncoding(charsetECI.EncodingName));
}
private static void addCharacterSet(int value, String[] encodingNames)
{
var eci = new CharacterSetECI(value, encodingNames[0]);
VALUE_TO_ECI[value] = eci; // can't use valueOf
foreach (string t in encodingNames)
{
NAME_TO_ECI[t] = eci;
}
}
/// <param name="value_Renamed">ECI value
/// </param>
/// <returns> {@link ECI} representing ECI of given value, or null if it is legal but unsupported
/// </returns>
/// <throws> IllegalArgumentException if ECI value is invalid </throws>
public static ECI getECIByValue(int value_Renamed)
{
if (value_Renamed < 0 || value_Renamed > 999999)
{
throw new System.ArgumentException("Bad ECI value: " + value_Renamed);
}
if (value_Renamed < 900)
{
// Character set ECIs use 000000 - 000899
return(CharacterSetECI.getCharacterSetECIByValue(value_Renamed));
}
return(null);
}
static StringUtils()
{
#if (NETFX_CORE || PORTABLE || NETSTANDARD)
PLATFORM_DEFAULT_ENCODING = UTF8;
PLATFORM_DEFAULT_ENCODING_T = Encoding.UTF8;
#else
PLATFORM_DEFAULT_ENCODING = Encoding.Default.WebName.ToUpper();
PLATFORM_DEFAULT_ENCODING_T = Encoding.Default;
#endif
SHIFT_JIS_ENCODING = CharacterSetECI.getEncoding(SHIFT_JIS);
GB2312_ENCODING = CharacterSetECI.getEncoding(GB2312);
EUC_JP_ENCODING = CharacterSetECI.getEncoding(EUC_JP);
ISO88591_ENCODING = CharacterSetECI.getEncoding(ISO88591);
ASSUME_SHIFT_JIS =
PLATFORM_DEFAULT_ENCODING_T.Equals(SHIFT_JIS_ENCODING) ||
PLATFORM_DEFAULT_ENCODING_T.Equals(EUC_JP_ENCODING);
}
private static void appendECI(CharacterSetECI eci, BitArray bits)
{
bits.appendBits(Mode.ECI.Bits, 4);
// This is correct for values up to 127, which is all we need now.
bits.appendBits(eci.Value, 8);
}
private static void addCharacterSet(int value, String[] encodingNames)
{
var eci = new CharacterSetECI(value, encodingNames[0]);
VALUE_TO_ECI[value] = eci; // can't use valueOf
foreach (string t in encodingNames)
{
NAME_TO_ECI[t] = eci;
}
}
private static void addCharacterSet(int value, String encodingName)
{
var eci = new CharacterSetECI(value, encodingName);
VALUE_TO_ECI[value] = eci; // can't use valueOf
NAME_TO_ECI[encodingName] = eci;
}
private static bool decodeByteSegment (BitSource bits,
StringBuilder result,
int count,
CharacterSetECI currentCharacterSetECI,
IList<byte[]> byteSegments,
IDictionary<DecodeHintType, object> hints)
{
// Don't crash trying to read more bits than we have available.
if (count << 3 > bits.available ()) {
return false;
}
byte[] readBytes = new byte[count];
for (int i = 0; i < count; i++) {
readBytes [i] = (byte)bits.readBits (8);
}
String encoding;
if (currentCharacterSetECI == null) {
// The spec isn't clear on this mode; see
// section 6.4.5: t does not say which encoding to assuming
// upon decoding. I have seen ISO-8859-1 used as well as
// Shift_JIS -- without anything like an ECI designator to
// give a hint.
encoding = StringUtils.guessEncoding (readBytes, hints);
} else {
encoding = currentCharacterSetECI.EncodingName;
}
try {
result.Append (Encoding.GetEncoding (encoding).GetString (readBytes, 0, readBytes.Length));
}
#if (WINDOWS_PHONE70 || WINDOWS_PHONE71 || SILVERLIGHT4 || SILVERLIGHT5 || NETFX_CORE || MONOANDROID || MONOTOUCH)
catch (ArgumentException)
{
try
{
// Silverlight only supports a limited number of character sets, trying fallback to UTF-8
result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
}
catch (Exception)
{
return false;
}
}
#endif
#if WindowsCE
catch (PlatformNotSupportedException)
{
try
{
// WindowsCE doesn't support all encodings. But it is device depended.
// So we try here the some different ones
if (encoding == "ISO-8859-1")
{
result.Append(Encoding.GetEncoding(1252).GetString(readBytes, 0, readBytes.Length));
}
else
{
result.Append(Encoding.GetEncoding("UTF-8").GetString(readBytes, 0, readBytes.Length));
}
}
catch (Exception)
{
return false;
}
}
#endif
catch (Exception) {
return false;
}
byteSegments.Add (readBytes);
return true;
}
/// <summary></summary>
/// <param name="bytes">bytes encoding a string, whose encoding should be guessed</param>
/// <param name="hints">decode hints if applicable</param>
/// <returns>Charset of guessed encoding; at the moment will only guess one of:
/// {@link #SHIFT_JIS_CHARSET}, {@link StandardCharsets#UTF_8},
/// {@link StandardCharsets#ISO_8859_1}, {@link StandardCharsets#UTF_16},
/// or the platform default encoding if
/// none of these can possibly be correct</returns>
public static Encoding guessCharset(byte[] bytes, IDictionary <DecodeHintType, object> hints)
{
if (hints != null && hints.ContainsKey(DecodeHintType.CHARACTER_SET))
{
String characterSet = (String)hints[DecodeHintType.CHARACTER_SET];
if (characterSet != null)
{
var encoding = CharacterSetECI.getEncoding(characterSet);
if (encoding != null)
{
return(encoding);
}
}
}
// First try UTF-16, assuming anything with its BOM is UTF-16
if (bytes.Length > 2 &&
((bytes[0] == (byte)0xFE && bytes[1] == (byte)0xFF) ||
(bytes[0] == (byte)0xFF && bytes[1] == (byte)0xFE)))
{
return(Encoding.Unicode);
}
// For now, merely tries to distinguish ISO-8859-1, UTF-8 and Shift_JIS,
// which should be by far the most common encodings.
int length = bytes.Length;
bool canBeISO88591 = true;
bool canBeShiftJIS = true;
bool canBeUTF8 = true;
int utf8BytesLeft = 0;
int utf2BytesChars = 0;
int utf3BytesChars = 0;
int utf4BytesChars = 0;
int sjisBytesLeft = 0;
int sjisKatakanaChars = 0;
int sjisCurKatakanaWordLength = 0;
int sjisCurDoubleBytesWordLength = 0;
int sjisMaxKatakanaWordLength = 0;
int sjisMaxDoubleBytesWordLength = 0;
int isoHighOther = 0;
bool utf8bom = bytes.Length > 3 &&
bytes[0] == 0xEF &&
bytes[1] == 0xBB &&
bytes[2] == 0xBF;
for (int i = 0;
i < length && (canBeISO88591 || canBeShiftJIS || canBeUTF8);
i++)
{
int value = bytes[i] & 0xFF;
// UTF-8 stuff
if (canBeUTF8)
{
if (utf8BytesLeft > 0)
{
if ((value & 0x80) == 0)
{
canBeUTF8 = false;
}
else
{
utf8BytesLeft--;
}
}
else if ((value & 0x80) != 0)
{
if ((value & 0x40) == 0)
{
canBeUTF8 = false;
}
else
{
utf8BytesLeft++;
if ((value & 0x20) == 0)
{
utf2BytesChars++;
}
else
{
utf8BytesLeft++;
if ((value & 0x10) == 0)
{
utf3BytesChars++;
}
else
{
utf8BytesLeft++;
if ((value & 0x08) == 0)
{
utf4BytesChars++;
}
else
{
canBeUTF8 = false;
}
}
}
}
}
}
// ISO-8859-1 stuff
if (canBeISO88591)
{
if (value > 0x7F && value < 0xA0)
{
canBeISO88591 = false;
}
else if (value > 0x9F)
{
if (value < 0xC0 || value == 0xD7 || value == 0xF7)
{
isoHighOther++;
}
}
}
// Shift_JIS stuff
if (canBeShiftJIS)
{
if (sjisBytesLeft > 0)
{
if (value < 0x40 || value == 0x7F || value > 0xFC)
{
canBeShiftJIS = false;
}
else
{
sjisBytesLeft--;
}
}
else if (value == 0x80 || value == 0xA0 || value > 0xEF)
{
canBeShiftJIS = false;
}
else if (value > 0xA0 && value < 0xE0)
{
sjisKatakanaChars++;
sjisCurDoubleBytesWordLength = 0;
sjisCurKatakanaWordLength++;
if (sjisCurKatakanaWordLength > sjisMaxKatakanaWordLength)
{
sjisMaxKatakanaWordLength = sjisCurKatakanaWordLength;
}
}
else if (value > 0x7F)
{
sjisBytesLeft++;
//sjisDoubleBytesChars++;
sjisCurKatakanaWordLength = 0;
sjisCurDoubleBytesWordLength++;
if (sjisCurDoubleBytesWordLength > sjisMaxDoubleBytesWordLength)
{
sjisMaxDoubleBytesWordLength = sjisCurDoubleBytesWordLength;
}
}
else
{
//sjisLowChars++;
sjisCurKatakanaWordLength = 0;
sjisCurDoubleBytesWordLength = 0;
}
}
}
if (canBeUTF8 && utf8BytesLeft > 0)
{
canBeUTF8 = false;
}
if (canBeShiftJIS && sjisBytesLeft > 0)
{
canBeShiftJIS = false;
}
// Easy -- if there is BOM or at least 1 valid not-single byte character (and no evidence it can't be UTF-8), done
if (canBeUTF8 && (utf8bom || utf2BytesChars + utf3BytesChars + utf4BytesChars > 0))
{
return(Encoding.UTF8);
}
// Easy -- if assuming Shift_JIS or >= 3 valid consecutive not-ascii characters (and no evidence it can't be), done
if (canBeShiftJIS && (ASSUME_SHIFT_JIS || sjisMaxKatakanaWordLength >= 3 || sjisMaxDoubleBytesWordLength >= 3))
{
return(SHIFT_JIS_ENCODING);
}
// Distinguishing Shift_JIS and ISO-8859-1 can be a little tough for short words. The crude heuristic is:
// - If we saw
// - only two consecutive katakana chars in the whole text, or
// - at least 10% of bytes that could be "upper" not-alphanumeric Latin1,
// - then we conclude Shift_JIS, else ISO-8859-1
if (canBeISO88591 && canBeShiftJIS)
{
return((sjisMaxKatakanaWordLength == 2 && sjisKatakanaChars == 2) || isoHighOther * 10 >= length
? SHIFT_JIS_ENCODING : ISO88591_ENCODING);
}
// Otherwise, try in order ISO-8859-1, Shift JIS, UTF-8 and fall back to default platform encoding
if (canBeISO88591)
{
return(ISO88591_ENCODING);
}
if (canBeShiftJIS)
{
return(SHIFT_JIS_ENCODING);
}
if (canBeUTF8)
{
return(Encoding.UTF8);
}
// Otherwise, we take a wild guess with platform encoding
return(PLATFORM_DEFAULT_ENCODING_T);
}