| /* |
| ************************************************************************** |
| * Copyright (C) 2005, International Business Machines Corporation and * |
| * others. All Rights Reserved. * |
| ************************************************************************** |
| * |
| */ |
| package com.ibm.icu.text; |
| |
| import java.util.Arrays; |
| |
| /** |
| * CharsetRecognizer implemenation for Asian - double or multi-byte - charsets. |
| * Match is determined mostly by the input data adhering to the |
| * encoding scheme for the charset, and, optionally, |
| * frequency-of-occurence of characters. |
| * <p/> |
| * Instances of this class are singletons, one per encoding |
| * being recognized. They are created in the main |
| * CharsetDetector class and kept in the global list of available |
| * encodings to be checked. The specific encoding being recognized |
| * is determined by subclass. |
| * |
| * @internal |
| */ |
| abstract class CharsetRecog_mbcs extends CharsetRecognizer { |
| |
| |
| |
| /** |
| * Get the IANA name of this charset. |
| * @return the charset name. |
| */ |
| abstract String getName() ; |
| |
| |
| /** |
| * Test the match of this charset with the input text data |
| * which is obtained via the CharsetDetector object. |
| * |
| * @param det The CharsetDetector, which contains the input text |
| * to be checked for being in this charset. |
| * @return Two values packed into one int (Damn java, anyhow) |
| * <br/> |
| * bits 0-7: the match confidence, ranging from 0-100 |
| * <br/> |
| * bits 8-15: The match reason, an enum-like value. |
| */ |
| int match(CharsetDetector det, int [] commonChars) { |
| int singleByteCharCount = 0; |
| int doubleByteCharCount = 0; |
| int commonCharCount = 0; |
| int badCharCount = 0; |
| int totalCharCount = 0; |
| int confidence = 0; |
| iteratedChar iter = new iteratedChar(); |
| |
| detectBlock: { |
| for (iter.reset(); nextChar(iter, det);) { |
| totalCharCount++; |
| if (iter.error) { |
| badCharCount++; |
| } else { |
| |
| if (iter.charValue <= 0xff) { |
| singleByteCharCount++; |
| } else { |
| doubleByteCharCount++; |
| if (commonChars != null) { |
| if (Arrays.binarySearch(commonChars, iter.charValue) >= 0){ |
| commonCharCount++; |
| } |
| } |
| } |
| } |
| if (badCharCount >= 2 && badCharCount*5 >= doubleByteCharCount) { |
| // Bail out early if the byte data is not matching the encoding scheme. |
| break detectBlock; |
| } |
| } |
| |
| if (doubleByteCharCount == 0 && badCharCount== 0) { |
| // No multi-byte chars. |
| // ASCII file? It's probably not our encoding, |
| // but is not incompatible with our encoding, so don't give it a zero. |
| confidence = 10; |
| break detectBlock; |
| } |
| |
| // |
| // No match if there are too many characters that don't fit the encoding scheme. |
| // (should we have zero tolerance for these?) |
| // |
| if (doubleByteCharCount < 20*badCharCount) { |
| confidence = 0; |
| break detectBlock; |
| } |
| |
| if (commonChars == null) { |
| // We have no statistics on frequently occuring characters. |
| // Assess confidence purely on having a reasonable number of |
| // multi-byte characters (the more the better |
| confidence = 30 + doubleByteCharCount - 20*badCharCount; |
| if (confidence > 100) { |
| confidence = 100; |
| } |
| }else { |
| // |
| // Frequency of occurence statistics exist. |
| // |
| double maxVal = Math.log((float)doubleByteCharCount / 4); |
| double scaleFactor = 90.0 / maxVal; |
| confidence = (int)(Math.log(commonCharCount+1) * scaleFactor + 10); |
| confidence = Math.min(confidence, 100); |
| } |
| } // end of detectBlock: |
| |
| return confidence; |
| } |
| |
| // "Character" iterated character class. |
| // Recognizers for specific mbcs encodings make their "characters" available |
| // by providing a nextChar() function that fills in an instance of iteratedChar |
| // with the next char from the input. |
| // The returned characters are not converted to Unicode, but remain as the raw |
| // bytes (concatenated into an int) from the codepage data. |
| // |
| // For Asian charsets, use the raw input rather than the input that has been |
| // stripped of markup. Detection only considers multi-byte chars, effectively |
| // stripping markup anyway, and double byte chars do occur in markup too. |
| // |
| static class iteratedChar { |
| int charValue = 0; // 1-4 bytes from the raw input data |
| int index = 0; |
| int nextIndex = 0; |
| boolean error = false; |
| boolean done = false; |
| |
| void reset() { |
| charValue = 0; |
| index = -1; |
| nextIndex = 0; |
| error = false; |
| done = false; |
| } |
| |
| int nextByte(CharsetDetector det) { |
| if (nextIndex >= det.fRawLength) { |
| done = true; |
| return -1; |
| } |
| int byteValue = (int)det.fRawInput[nextIndex++] & 0x00ff; |
| return byteValue; |
| } |
| } |
| |
| /** |
| * Get the next character (however many bytes it is) from the input data |
| * Subclasses for specific charset encodings must implement this function |
| * to get characters according to the rules of their encoding scheme. |
| * |
| * This function is not a method of class iteratedChar only because |
| * that would require a lot of extra derived classes, which is awkward. |
| * @param it The iteratedChar "struct" into which the returned char is placed. |
| * @param det The charset detector, which is needed to get at the input byte data |
| * being iterated over. |
| * @return True if a character was returned, false at end of input. |
| */ |
| abstract boolean nextChar(iteratedChar it, CharsetDetector det); |
| |
| |
| |
| |
| |
| /** |
| * Shift-JIS charset recognizer. |
| * |
| */ |
| static class CharsetRecog_sjis extends CharsetRecog_mbcs { |
| static int [] commonChars = |
| // TODO: This set of data comes from the character frequency- |
| // of-occurence analysis tool. The data needs to be moved |
| // into a resource and loaded from there. |
| {0x82cc, 0x82c5, 0x82a2, 0x815b, 0x8141, 0x82b5, 0x82c9, 0x82b7, 0x8142, 0x82c4, |
| 0x82c6, 0x82cd, 0x82dc, 0x82f0, 0x82e9, 0x82c8, 0x82aa, 0x8393, 0x82bd, 0x8358, |
| 0x82ea, 0x8343, 0x82a4, 0x82a9, 0x8367, 0x82b1, 0x8145, 0x82e0, 0x838b, 0x834e, |
| 0x82e8, 0x82e7, 0x8140, 0x8362, 0x8389, 0x82c1, 0x838a, 0x82ab, 0x8376, 0x82b3, |
| 0x82f1, 0x82a0, 0x8368, 0x93fa, 0x8175, 0x8176, 0x835e, 0x82e6, 0x8357, 0x82ad, |
| 0x8381, 0x82a6, 0x82b9, 0x82bb, 0x82be, 0x8341, 0x8374, 0x82af, 0x9056, 0x82a8, |
| 0x82c2, 0x8354, 0x8e67, 0x8375, 0x82c7, 0x95f1, 0x8356, 0x967b, 0x92e8, 0x8345, |
| 0x82ce, 0x8385, 0x9770, 0x82df, 0x82dd, 0x836f, 0x8342, 0x8ca7, 0x8352, 0x837d, |
| 0x838d, 0x8346, 0x834f, 0x8380, 0x82ed, 0x8d73, 0x8349, 0x8365, 0x8fee, 0x95b6, |
| 0x8169, 0x816a, 0x836a, 0x8dec, 0x82bf, 0x834c, 0x8366, 0x82e2, 0x838c, 0x945c}; |
| |
| boolean nextChar(iteratedChar it, CharsetDetector det) { |
| it.index = it.nextIndex; |
| it.error = false; |
| int firstByte; |
| firstByte = it.charValue = it.nextByte(det); |
| if (firstByte < 0) { |
| return false; |
| } |
| |
| if (firstByte <= 0x7f || (firstByte>0xa0 && firstByte<=0xdf)) { |
| return true; |
| } |
| |
| int secondByte = it.nextByte(det); |
| if (secondByte < 0) { |
| return false; |
| } |
| it.charValue = (firstByte << 8) | secondByte; |
| if (! ((secondByte>=0x40 && secondByte<=0x7f) || (secondByte>=0x80 && secondByte<=0xff))) { |
| // Illegal second byte value. |
| it.error = true; |
| } |
| return true; |
| } |
| |
| int match(CharsetDetector det) { |
| return match(det, commonChars); |
| } |
| |
| String getName() { |
| return "Shift_JIS"; |
| } |
| |
| } |
| |
| |
| /** |
| * EUC charset recognizers. One abstract class that provides the common function |
| * for getting the next character according to the EUC encoding scheme, |
| * and nested derived classes for EUC_KR, EUC_JP, EUC_CN. |
| * |
| */ |
| abstract static class CharsetRecog_euc extends CharsetRecog_mbcs { |
| |
| /* |
| * (non-Javadoc) |
| * Get the next character value for EUC based encodings. |
| * Character "value" is simply the raw bytes that make up the character |
| * packed into an int. |
| */ |
| boolean nextChar(iteratedChar it, CharsetDetector det) { |
| it.index = it.nextIndex; |
| it.error = false; |
| int firstByte = 0; |
| int secondByte = 0; |
| int thirdByte = 0; |
| int fourthByte = 0; |
| |
| buildChar: { |
| firstByte = it.charValue = it.nextByte(det); |
| if (firstByte < 0) { |
| // Ran off the end of the input data |
| it.done = true; |
| break buildChar; |
| } |
| if (firstByte <= 0x8d) { |
| // single byte char |
| break buildChar; |
| } |
| |
| secondByte = it.nextByte(det); |
| it.charValue = (it.charValue << 8) | secondByte; |
| |
| if (firstByte >= 0xA1 && firstByte <= 0xfe) { |
| // Two byte Char |
| if (secondByte < 0xa1) { |
| it.error = true; |
| } |
| break buildChar; |
| } |
| if (firstByte == 0x8e) { |
| // Code Set 2. |
| // In EUC-JP, total char size is 2 bytes, only one byte of actual char value. |
| // In EUC-TW, total char size is 4 bytes, three bytes contribute to char value. |
| // We don't know which we've got. |
| // Treat it like EUC-JP. If the data really was EUC-TW, the following two |
| // bytes will look like a well formed 2 byte char. |
| if (secondByte < 0xa1) { |
| it.error = true; |
| } |
| break buildChar; |
| } |
| |
| if (firstByte == 0x8f) { |
| // Code set 3. |
| // Three byte total char size, two bytes of actual char value. |
| thirdByte = it.nextByte(det); |
| it.charValue = (it.charValue << 8) | thirdByte; |
| if (thirdByte < 0xa1) { |
| it.error = true; |
| } |
| } |
| } |
| |
| return (it.done == false); |
| } |
| |
| /** |
| * The charset recognize for EUC-JP. A singleton instance of this class |
| * is created and kept by the public CharsetDetector class |
| */ |
| static class CharsetRecog_euc_jp extends CharsetRecog_euc { |
| static int [] commonChars = |
| // TODO: This set of data comes from the character frequency- |
| // of-occurence analysis tool. The data needs to be moved |
| // into a resource and loaded from there. |
| {0xa4ce, 0xa4c7, 0xa4a4, 0xa1bc, 0xa1a2, 0xa4b7, 0xa4cb, 0xa4b9, 0xa1a3, 0xa4c6, |
| 0xa4c8, 0xa4cf, 0xa4de, 0xa4f2, 0xa4eb, 0xa4ca, 0xa4ac, 0xa5f3, 0xa4bf, 0xa5b9, |
| 0xa4ec, 0xa5a4, 0xa4a6, 0xa4ab, 0xa5c8, 0xa4b3, 0xa1a6, 0xa4e2, 0xa5eb, 0xa5af, |
| 0xa4ea, 0xa4e9, 0xa1a1, 0xa5c3, 0xa5e9, 0xa4c3, 0xa5ea, 0xa4ad, 0xa5d7, 0xa4b5, |
| 0xa4f3, 0xa4a2, 0xa5c9, 0xc6fc, 0xa1d6, 0xa1d7, 0xa5bf, 0xa4e8, 0xa5b8, 0xa4af, |
| 0xa5e1, 0xa4a8, 0xa4bb, 0xa4bd, 0xa4c0, 0xa5a2, 0xa5d5, 0xa4b1, 0xbfb7, 0xa4aa, |
| 0xa4c4, 0xa5b5, 0xbbc8, 0xa5d6, 0xa4c9, 0xcaf3, 0xa5b7, 0xcbdc, 0xc4ea, 0xa5a6, |
| 0xa4d0, 0xa5e5, 0xcdd1, 0xa4e1, 0xa4df, 0xa5d0, 0xa5a3, 0xb8a9, 0xa5b3, 0xa5de, |
| 0xa5ed, 0xa5a7, 0xa5b0, 0xa5e0, 0xa4ef, 0xb9d4, 0xa5aa, 0xa5c6, 0xbef0, 0xcab8, |
| 0xa1ca, 0xa1cb, 0xa5cb, 0xbaee, 0xa4c1, 0xa5ad, 0xa5c7, 0xa4e4, 0xa5ec, 0xc7bd}; |
| |
| String getName() { |
| return "EUC-JP"; |
| } |
| |
| int match(CharsetDetector det) { |
| return match(det, commonChars); |
| } |
| } |
| |
| /** |
| * The charset recognize for EUC-KR. A singleton instance of this class |
| * is created and kept by the public CharsetDetector class |
| */ |
| static class CharsetRecog_euc_kr extends CharsetRecog_euc { |
| static int [] commonChars = |
| // TODO: This set of data comes from the character frequency- |
| // of-occurence analysis tool. The data needs to be moved |
| // into a resource and loaded from there. |
| {0xc0cc, 0xb4d9, 0xb4c2, 0xc0c7, 0xbfa1, 0xc7cf, 0xb0a1, 0xb0ed, 0xc7d1, 0xc1f6, |
| 0xc0bb, 0xb7ce, 0xb1e2, 0xbcad, 0xc0ba, 0xbbe7, 0xc1a4, 0xc0da, 0xb5b5, 0xb8a6, |
| 0xbeee, 0xb4cf, 0xbcf6, 0xbdc3, 0xb1d7, 0xb4eb, 0xb8ae, 0xc0ce, 0xb3aa, 0xbec6, |
| 0xc0d6, 0xbab8, 0xb5e9, 0xb6f3, 0xc7d8, 0xb0cd, 0xc0cf, 0xbdba, 0xc0b8, 0xb1b9, |
| 0xc1a6, 0xb9fd, 0xbbf3, 0xb0d4, 0xb8e9, 0xb8b8, 0xb0fa, 0xc0fb, 0xbace, 0xc1d6, |
| 0xbfa9, 0xc0fc, 0xbfeb, 0xb9ae, 0xc6ae, 0xbbfd, 0xbcba, 0xc0a7, 0xbff8, 0xb5c7, |
| 0xbfe4, 0xbfec, 0xbdc5, 0xc7d2, 0xc7e5, 0xb0fc, 0xb1b8, 0xbaf1, 0xbedf, 0xc5cd, |
| 0xb8b6, 0xbdc0, 0xb7af, 0xb5bf, 0xb3bb, 0xc8ad, 0xc0bd, 0xb0b3, 0xc4a1, 0xb7c2, |
| 0xb9ab, 0xc0af, 0xbef8, 0xb5a5, 0xbcd2, 0xb9ce, 0xc1df, 0xbfc0, 0xc1f8, 0xb0e6, |
| 0xb1c7, 0xbad0, 0xbefa, 0xc0e5, 0xbec8, 0xc1b6, 0xb8bb, 0xb0f8, 0xb9cc, 0xb0c5}; |
| |
| String getName() { |
| return "EUC-KR"; |
| } |
| |
| int match(CharsetDetector det) { |
| return match(det, commonChars); |
| } |
| } |
| } |
| |
| /** |
| * |
| * GB-18030 recognizer. Uses simplified Chinese statistics. |
| * |
| */ |
| static class CharsetRecog_gb_18030 extends CharsetRecog_mbcs { |
| |
| /* |
| * (non-Javadoc) |
| * Get the next character value for EUC based encodings. |
| * Character "value" is simply the raw bytes that make up the character |
| * packed into an int. |
| */ |
| boolean nextChar(iteratedChar it, CharsetDetector det) { |
| it.index = it.nextIndex; |
| it.error = false; |
| int firstByte = 0; |
| int secondByte = 0; |
| int thirdByte = 0; |
| int fourthByte = 0; |
| |
| buildChar: { |
| firstByte = it.charValue = it.nextByte(det); |
| |
| if (firstByte < 0) { |
| // Ran off the end of the input data |
| it.done = true; |
| break buildChar; |
| } |
| |
| if (firstByte <= 0x80) { |
| // single byte char |
| break buildChar; |
| } |
| |
| secondByte = it.nextByte(det); |
| it.charValue = (it.charValue << 8) | secondByte; |
| |
| if (firstByte >= 0x81 && firstByte <= 0xFE) { |
| // Two byte Char |
| if ((secondByte >= 0x40 && secondByte <= 0x7E) || (secondByte >=80 && secondByte <=0xFE)) { |
| break buildChar; |
| } |
| |
| // Four byte char |
| if (secondByte >= 0x30 && secondByte <= 0x39) { |
| thirdByte = it.nextByte(det); |
| |
| if (thirdByte >= 0x81 && thirdByte <= 0xFE) { |
| fourthByte = it.nextByte(det); |
| |
| if (fourthByte >= 0x30 && fourthByte <= 0x39) { |
| it.charValue = (it.charValue << 16) | (thirdByte << 8) | fourthByte; |
| break buildChar; |
| } |
| } |
| } |
| |
| it.error = true; |
| break buildChar; |
| } |
| } |
| |
| return (it.done == false); |
| } |
| |
| static int [] commonChars = |
| // TODO: This set of data comes from the character frequency- |
| // of-occurence analysis tool. The data needs to be moved |
| // into a resource and loaded from there. |
| {0xa3ac, 0xb5c4, 0xa1a1, 0xa1a4, 0xa1a3, 0xcac7, 0xd2bb, 0xb4f3, 0xd4da, 0xd6d0, |
| 0xcafd, 0xd3d0, 0xa1f3, 0xb2bb, 0xa3ba, 0xbbfa, 0xc8cb, 0xa1a2, 0xd3c3, 0xd1a7, |
| 0xc8d5, 0xbedd, 0xb8f6, 0xd0c2, 0xcdf8, 0xd2aa, 0xb9fa, 0xc1cb, 0xc9cf, 0xa1b0, |
| 0xa1b1, 0xced2, 0xbcfe, 0xcec4, 0xd2d4, 0xc4dc, 0xc0b4, 0xd4c2, 0xcab1, 0xd0d0, |
| 0xbdcc, 0xbfc9, 0xb6d4, 0xbcdb, 0xb1be, 0xb3f6, 0xb8b4, 0xc9fa, 0xb1b8, 0xbcbc, |
| 0xcfc2, 0xbacd, 0xbecd, 0xb3c9, 0xd5e2, 0xb8df, 0xb7d6, 0xc5cc, 0xbfc6, 0xbbe1, |
| 0xceaa, 0xc8e7, 0xcfb5, 0xa1f1, 0xc4ea, 0xb1a8, 0xb6af, 0xc0ed, 0xd3fd, 0xb7a2, |
| 0xc8ab, 0xb7bd, 0xcee5, 0xc2db, 0xbba7, 0xd0d4, 0xb9c9, 0xc3c7, 0xb9fd, 0xcad0, |
| 0xb5e3, 0xbbd6, 0xcfd6, 0xcab5, 0xd2b2, 0xbfb4, 0xb6e0, 0xccec, 0xc7f8, 0xd0c5, |
| 0xcad6, 0xb9d8, 0xb5bd, 0xb7dd, 0xc6f7, 0xcaf5, 0xa3a1, 0xb7a8, 0xb9ab, 0xd2b5, |
| 0xcbf9, 0xcdbc, 0xc6e4, 0xd3da, 0xd0a1, 0xd1a1, 0xd3ce, 0xbfaa, 0xb4e6, 0xc4bf, |
| 0xd7f7, 0xb5e7, 0xcdb3, 0xc7e9, 0xd7ee, 0xc6c0, 0xcfdf, 0xb5d8, 0xb5c0, 0xbead, |
| 0xb4c5, 0xc6b7, 0xc4da, 0xd0c4, 0xb9a4, 0xd4aa, 0xc2bc, 0xc3c0, 0xbaf3, 0xcabd, |
| 0xbcd2, 0xcef1, 0xbdab, 0xa3ad, 0xa3bf, 0xb3a4, 0xb9fb, 0xd6ae, 0xc1bf, 0xbbd8, |
| 0xb8f1, 0xb6f8, 0xb6a8, 0xcde2, 0xbac3, 0xb3cc, 0xccd8, 0xd7d4, 0xcbb5}; |
| |
| String getName() { |
| return "GB18030"; |
| } |
| |
| int match(CharsetDetector det) { |
| return match(det, commonChars); |
| } |
| } |
| |
| |
| } |
