CharsetICU.java
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2006-2016, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*/
package com.ibm.icu.charset;
import com.ibm.icu.text.UnicodeSet;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.util.HashMap;
/**
* A subclass of java.nio.Charset for providing implementation of ICU's charset converters. This API
* is used to convert codepage or character encoded data to and from UTF-16. You can open a
* converter with {@link Charset#forName} and {@link #forNameICU}. With that converter, you can get
* its properties, set options, convert your data.
*
* <p>Since many software programs recognize different converter names for different types of
* converters, there are other functions in this API to iterate over the converter aliases.
*
* <p>Note that {@link #name()} cannot always return a unique charset name. {@link Charset}
* documents that, for charsets listed in the IANA Charset Registry, the {@link #name()} must be
* listed there, and it “must be the MIME-preferred name” if there are multiple names.
*
* <p>However, there are different implementations of many if not most charsets, ICU provides
* multiple variants for some of them, ICU provides variants of some java.nio-system-supported
* charsets, and ICU users are free to add more variants. This is so that applications can be
* compatible with multiple implementations at the same time.
*
* <p>This is in conflict with the {@link Charset#name()} requirements. It is not possible to offer
* variants of an IANA charset and always use the MIME-preferred name and also have those names be
* unique.
*
* <p>{@link #name()} returns the MIME-preferred name, or IANA name, so that it can always be used
* for the charset field in internet protocols.
*
* <p>Same-name charsets are accessible via {@link Charset#forName} or {@link #forNameICU} by using
* unique aliases (e.g., the ICU-canonical names).
*
* <p>{@link Charset} also documents that “Two charsets are equal if, and only if, they have the
* same canonical names.” This is not possible.
*
* <p>Unfortunately, {@link Charset#equals} is final, and {@link Charset#availableCharsets} returns
* “a sorted map from canonical charset names to charset objects”. Since {@link #name()} cannot be
* unique, {@link #equals} cannot work properly in such cases, and {@link Charset#availableCharsets}
* can only include one variant for a name.
*
* @stable ICU 3.6
*/
public abstract class CharsetICU extends Charset {
String icuCanonicalName;
int options;
float maxCharsPerByte;
String name; /* +4: 60 internal name of the converter- invariant chars */
int codepage; /* +64: 4 codepage # (now IBM-$codepage) */
byte platform; /* +68: 1 platform of the converter (only IBM now) */
byte conversionType; /* +69: 1 conversion type */
int minBytesPerChar; /* +70: 1 Minimum # bytes per char in this codepage */
int maxBytesPerChar; /* +71: 1 Maximum # bytes output per UChar in this codepage */
byte subChar[ /*UCNV_MAX_SUBCHAR_LEN*/]; /* +72: 4 [note: 4 and 8 byte boundary] */
byte subCharLen; /* +76: 1 */
byte
hasToUnicodeFallback; /* +77: 1 UBool needs to be changed to UBool to be consistent across platform */
byte hasFromUnicodeFallback; /* +78: 1 */
short unicodeMask; /* +79: 1 bit 0: has supplementary bit 1: has single surrogates */
byte subChar1; /* +80: 1 single-byte substitution character for IBM MBCS (0 if none) */
// byte reserved[/*19*/]; /* +81: 19 to round out the structure */
// typedef enum UConverterUnicodeSet {
/**
* Parameter that select the set of roundtrippable Unicode code points.
*
* @stable ICU 4.0
*/
public static final int ROUNDTRIP_SET = 0;
/**
* Select the set of Unicode code points with roundtrip or fallback mappings. Not supported at
* this point.
*
* @internal
* @deprecated This API is ICU internal only.
*/
@Deprecated public static final int ROUNDTRIP_AND_FALLBACK_SET = 1;
// } UConverterUnicodeSet;
/**
* @param icuCanonicalName
* @param canonicalName
* @param aliases
* @stable ICU 3.6
*/
protected CharsetICU(String icuCanonicalName, String canonicalName, String[] aliases) {
super(canonicalName, aliases);
if (canonicalName.length() == 0) {
throw new IllegalCharsetNameException(canonicalName);
}
this.icuCanonicalName = icuCanonicalName;
}
/**
* Ascertains if a charset is a sub set of this charset Implements the abstract method of super
* class.
*
* @param cs charset to test
* @return true if the given charset is a subset of this charset
* @stable ICU 3.6
*/
@Override
public boolean contains(Charset cs) {
if (null == cs) {
return false;
} else if (this.equals(cs)) {
return true;
}
return false;
}
private static final HashMap<String, String> algorithmicCharsets =
new HashMap<String, String>();
static {
algorithmicCharsets.put("LMBCS-1", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-2", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-3", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-4", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-5", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-6", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-8", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-11", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-16", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-17", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-18", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("LMBCS-19", "com.ibm.icu.charset.CharsetLMBCS");
algorithmicCharsets.put("BOCU-1", "com.ibm.icu.charset.CharsetBOCU1");
algorithmicCharsets.put("SCSU", "com.ibm.icu.charset.CharsetSCSU");
algorithmicCharsets.put("US-ASCII", "com.ibm.icu.charset.CharsetASCII");
algorithmicCharsets.put("ISO-8859-1", "com.ibm.icu.charset.Charset88591");
algorithmicCharsets.put("UTF-16", "com.ibm.icu.charset.CharsetUTF16");
algorithmicCharsets.put("UTF-16BE", "com.ibm.icu.charset.CharsetUTF16BE");
algorithmicCharsets.put("UTF-16BE,version=1", "com.ibm.icu.charset.CharsetUTF16BE");
algorithmicCharsets.put("UTF-16LE", "com.ibm.icu.charset.CharsetUTF16LE");
algorithmicCharsets.put("UTF-16LE,version=1", "com.ibm.icu.charset.CharsetUTF16LE");
algorithmicCharsets.put("UTF16_OppositeEndian", "com.ibm.icu.charset.CharsetUTF16LE");
algorithmicCharsets.put("UTF16_PlatformEndian", "com.ibm.icu.charset.CharsetUTF16");
algorithmicCharsets.put("UTF-32", "com.ibm.icu.charset.CharsetUTF32");
algorithmicCharsets.put("UTF-32BE", "com.ibm.icu.charset.CharsetUTF32BE");
algorithmicCharsets.put("UTF-32LE", "com.ibm.icu.charset.CharsetUTF32LE");
algorithmicCharsets.put("UTF32_OppositeEndian", "com.ibm.icu.charset.CharsetUTF32LE");
algorithmicCharsets.put("UTF32_PlatformEndian", "com.ibm.icu.charset.CharsetUTF32");
algorithmicCharsets.put("UTF-8", "com.ibm.icu.charset.CharsetUTF8");
algorithmicCharsets.put("CESU-8", "com.ibm.icu.charset.CharsetCESU8");
algorithmicCharsets.put("UTF-7", "com.ibm.icu.charset.CharsetUTF7");
algorithmicCharsets.put("ISCII,version=0", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("ISCII,version=1", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("ISCII,version=2", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("ISCII,version=3", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("ISCII,version=4", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("ISCII,version=5", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("ISCII,version=6", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("ISCII,version=7", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("ISCII,version=8", "com.ibm.icu.charset.CharsetISCII");
algorithmicCharsets.put("IMAP-mailbox-name", "com.ibm.icu.charset.CharsetUTF7");
algorithmicCharsets.put("HZ", "com.ibm.icu.charset.CharsetHZ");
algorithmicCharsets.put(
"ISO_2022,locale=ja,version=0", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=ja,version=1", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=ja,version=2", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=ja,version=3", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=ja,version=4", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=zh,version=0", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=zh,version=1", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=zh,version=2", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=ko,version=0", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put(
"ISO_2022,locale=ko,version=1", "com.ibm.icu.charset.CharsetISO2022");
algorithmicCharsets.put("x11-compound-text", "com.ibm.icu.charset.CharsetCompoundText");
}
/*public*/ static final Charset getCharset(
String icuCanonicalName, String javaCanonicalName, String[] aliases) {
String className = algorithmicCharsets.get(icuCanonicalName);
if (className == null) {
// all the cnv files are loaded as MBCS
className = "com.ibm.icu.charset.CharsetMBCS";
}
try {
CharsetICU conv = null;
Class<? extends CharsetICU> cs = Class.forName(className).asSubclass(CharsetICU.class);
Class<?>[] paramTypes = new Class<?>[] {String.class, String.class, String[].class};
final Constructor<? extends CharsetICU> c = cs.getConstructor(paramTypes);
Object[] params = new Object[] {icuCanonicalName, javaCanonicalName, aliases};
// Run constructor
try {
conv = c.newInstance(params);
if (conv != null) {
return conv;
}
} catch (InvocationTargetException e) {
Throwable cause = e.getCause();
UnsupportedCharsetException e2 =
new UnsupportedCharsetException(
icuCanonicalName
+ ": "
+ "Could not load "
+ className
+ ". Exception: "
+ cause);
e2.initCause(cause);
throw e2;
}
} catch (ClassNotFoundException ex) {
} catch (NoSuchMethodException ex) {
} catch (IllegalAccessException ex) {
} catch (InstantiationException ex) {
}
throw new UnsupportedCharsetException(
icuCanonicalName + ": " + "Could not load " + className);
}
static final boolean isSurrogate(int c) {
return (((c) & 0xfffff800) == 0xd800);
}
/*
* Returns the default charset name
*/
// static final String getDefaultCharsetName(){
// String defaultEncoding = new InputStreamReader(new ByteArrayInputStream(new
// byte[0])).getEncoding();
// return defaultEncoding;
// }
/**
* Returns a charset object for the named charset. This method guarantees that ICU charset is
* returned when available. If the ICU charset provider does not support the specified charset,
* then try other charset providers including the standard Java charset provider.
*
* @param charsetName The name of the requested charset, may be either a canonical name or an
* alias
* @return A charset object for the named charset
* @throws IllegalCharsetNameException If the given charset name is illegal
* @throws UnsupportedCharsetException If no support for the named charset is available in this
* instance of th Java virtual machine
* @stable ICU 3.6
*/
public static Charset forNameICU(String charsetName)
throws IllegalCharsetNameException, UnsupportedCharsetException {
CharsetProviderICU icuProvider = new CharsetProviderICU();
CharsetICU cs = (CharsetICU) icuProvider.charsetForName(charsetName);
if (cs != null) {
return cs;
}
return Charset.forName(charsetName);
}
// /**
// * @see java.lang.Comparable#compareTo(java.lang.Object)
// * @stable 3.8
// */
// public int compareTo(Object otherObj) {
// if (!(otherObj instanceof CharsetICU)) {
// return -1;
// }
// return icuCanonicalName.compareTo(((CharsetICU)otherObj).icuCanonicalName);
// }
/**
* This follows ucnv.c method ucnv_detectUnicodeSignature() to detect the start of the stream
* for example U+FEFF (the Unicode BOM/signature character) that can be ignored.
*
* <p>Detects Unicode signature byte sequences at the start of the byte stream and returns
* number of bytes of the BOM of the indicated Unicode charset. 0 is returned when no Unicode
* signature is recognized.
*/
// TODO This should be proposed as CharsetDecoderICU API.
// static String detectUnicodeSignature(ByteBuffer source) {
// int signatureLength = 0; // number of bytes of the signature
// final int SIG_MAX_LEN = 5;
// String sigUniCharset = null; // states what unicode charset is the BOM
// int i = 0;
//
// /*
// * initial 0xa5 bytes: make sure that if we read <SIG_MAX_LEN bytes we
// * don't misdetect something
// */
// byte start[] = { (byte) 0xa5, (byte) 0xa5, (byte) 0xa5, (byte) 0xa5,
// (byte) 0xa5 };
//
// while (i < source.remaining() && i < SIG_MAX_LEN) {
// start[i] = source.get(i);
// i++;
// }
//
// if (start[0] == (byte) 0xFE && start[1] == (byte) 0xFF) {
// signatureLength = 2;
// sigUniCharset = "UTF-16BE";
// source.position(signatureLength);
// return sigUniCharset;
// } else if (start[0] == (byte) 0xFF && start[1] == (byte) 0xFE) {
// if (start[2] == (byte) 0x00 && start[3] == (byte) 0x00) {
// signatureLength = 4;
// sigUniCharset = "UTF-32LE";
// source.position(signatureLength);
// return sigUniCharset;
// } else {
// signatureLength = 2;
// sigUniCharset = "UTF-16LE";
// source.position(signatureLength);
// return sigUniCharset;
// }
// } else if (start[0] == (byte) 0xEF && start[1] == (byte) 0xBB
// && start[2] == (byte) 0xBF) {
// signatureLength = 3;
// sigUniCharset = "UTF-8";
// source.position(signatureLength);
// return sigUniCharset;
// } else if (start[0] == (byte) 0x00 && start[1] == (byte) 0x00
// && start[2] == (byte) 0xFE && start[3] == (byte) 0xFF) {
// signatureLength = 4;
// sigUniCharset = "UTF-32BE";
// source.position(signatureLength);
// return sigUniCharset;
// } else if (start[0] == (byte) 0x0E && start[1] == (byte) 0xFE
// && start[2] == (byte) 0xFF) {
// signatureLength = 3;
// sigUniCharset = "SCSU";
// source.position(signatureLength);
// return sigUniCharset;
// } else if (start[0] == (byte) 0xFB && start[1] == (byte) 0xEE
// && start[2] == (byte) 0x28) {
// signatureLength = 3;
// sigUniCharset = "BOCU-1";
// source.position(signatureLength);
// return sigUniCharset;
// } else if (start[0] == (byte) 0x2B && start[1] == (byte) 0x2F
// && start[2] == (byte) 0x76) {
//
// if (start[3] == (byte) 0x38 && start[4] == (byte) 0x2D) {
// signatureLength = 5;
// sigUniCharset = "UTF-7";
// source.position(signatureLength);
// return sigUniCharset;
// } else if (start[3] == (byte) 0x38 || start[3] == (byte) 0x39
// || start[3] == (byte) 0x2B || start[3] == (byte) 0x2F) {
// signatureLength = 4;
// sigUniCharset = "UTF-7";
// source.position(signatureLength);
// return sigUniCharset;
// }
// } else if (start[0] == (byte) 0xDD && start[2] == (byte) 0x73
// && start[2] == (byte) 0x66 && start[3] == (byte) 0x73) {
// signatureLength = 4;
// sigUniCharset = "UTF-EBCDIC";
// source.position(signatureLength);
// return sigUniCharset;
// }
//
// /* no known Unicode signature byte sequence recognized */
// return null;
// }
abstract void getUnicodeSetImpl(UnicodeSet setFillIn, int which);
/**
* Returns the set of Unicode code points that can be converted by an ICU Converter.
*
* <p>The current implementation returns only one kind of set (UCNV_ROUNDTRIP_SET): The set of
* all Unicode code points that can be roundtrip-converted (converted without any data loss)
* with the converter This set will not include code points that have fallback mappings or are
* only the result of reverse fallback mappings. See UTR #22 "Character Mapping Markup Language"
* at <a href="http://www.unicode.org/reports/tr22/">http://www.unicode.org/reports/tr22/</a>
*
* <p>In the future, there may be more UConverterUnicodeSet choices to select sets with
* different properties.
*
* <p>This is useful for example for
*
* <ul>
* <li>checking that a string or document can be roundtrip-converted with a converter,
* without/before actually performing the conversion
* <li>testing if a converter can be used for text for typical text for a certain locale, by
* comparing its roundtrip set with the set of ExemplarCharacters from ICU's locale data
* or other sources
* </ul>
*
* @param setFillIn A valid UnicodeSet. It will be cleared by this function before the
* converter's specific set is filled in.
* @param which A selector; currently ROUNDTRIP_SET is the only supported value.
* @throws IllegalArgumentException if the parameters does not match.
* @stable ICU 4.0
*/
public void getUnicodeSet(UnicodeSet setFillIn, int which) {
if (setFillIn == null || which != ROUNDTRIP_SET) {
throw new IllegalArgumentException();
}
setFillIn.clear();
getUnicodeSetImpl(setFillIn, which);
}
/**
* Returns whether or not the charset of the converter has a fixed number of bytes per charset
* character. An example of this are converters that are of the type UCNV_SBCS or UCNV_DBCS.
* Another example is UTF-32 which is always 4 bytes per character. A UTF-32 code point may
* represent more than one UTF-8 or UTF-16 code units but always have size of 4 bytes. Note:
* This method is not intended to be used to determine whether the charset has a fixed ratio of
* bytes to Unicode codes units for any particular Unicode encoding form.
*
* @return true if the converter is fixed-width
* @stable ICU 4.8
*/
public boolean isFixedWidth() {
if (this instanceof CharsetASCII || this instanceof CharsetUTF32) {
return true;
}
if (this instanceof CharsetMBCS) {
if (((CharsetMBCS) this).sharedData.staticData.maxBytesPerChar
== ((CharsetMBCS) this).sharedData.staticData.minBytesPerChar) {
return true;
}
}
return false;
}
static void getNonSurrogateUnicodeSet(UnicodeSet setFillIn) {
setFillIn.add(0, 0xd7ff);
setFillIn.add(0xe000, 0x10ffff);
}
static void getCompleteUnicodeSet(UnicodeSet setFillIn) {
setFillIn.add(0, 0x10ffff);
}
}