Internationalization Java

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import java.io.UnsupportedEncodingException;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.util.HashMap;
import java.util.Map;
import java.util.SortedSet;
import java.util.TreeSet;
/**
 * Utility class for working with character sets. It is somewhat similar to
 * the Java 1.4 java.nio.charset.Charset class but knows many
 * more aliases and is compatible with Java 1.3. It will use a simple detection
 * mechanism to detect what character sets the current VM supports. This will
 * be a sub-set of the character sets listed in the
 * 
 * Java 1.5 (J2SE5.0) Supported Encodings document.
 * 


 * The 
 * IANA Character Sets document has been used to determine the preferred
 * MIME character set names and to get a list of known aliases.
 * 


 * This is a complete list of the character sets known to this class:
 * 


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Canonical (Java) nameMIME preferredAliases
ASCIIUS-ASCIIANSI_X3.4-1968 iso-ir-6 ANSI_X3.4-1986 ISO_646.irv:1991 ISO646-US us IBM367 cp367 csASCII ascii7 646 iso_646.irv:1983 
Big5Big5csBig5 CN-Big5 BIG-FIVE BIGFIVE 
Big5_HKSCSBig5-HKSCSbig5hkscs 
Big5_Solaris?
Cp037IBM037ebcdic-cp-us ebcdic-cp-ca ebcdic-cp-wt ebcdic-cp-nl csIBM037 
Cp1006?
Cp1025?
Cp1026IBM1026csIBM1026 
Cp1046?
Cp1047IBM1047IBM-1047 
Cp1097?
Cp1098?
Cp1112?
Cp1122?
Cp1123?
Cp1124?
Cp1140IBM01140CCSID01140 CP01140 ebcdic-us-37+euro 
Cp1141IBM01141CCSID01141 CP01141 ebcdic-de-273+euro 
Cp1142IBM01142CCSID01142 CP01142 ebcdic-dk-277+euro ebcdic-no-277+euro 
Cp1143IBM01143CCSID01143 CP01143 ebcdic-fi-278+euro ebcdic-se-278+euro 
Cp1144IBM01144CCSID01144 CP01144 ebcdic-it-280+euro 
Cp1145IBM01145CCSID01145 CP01145 ebcdic-es-284+euro 
Cp1146IBM01146CCSID01146 CP01146 ebcdic-gb-285+euro 
Cp1147IBM01147CCSID01147 CP01147 ebcdic-fr-297+euro 
Cp1148IBM01148CCSID01148 CP01148 ebcdic-international-500+euro 
Cp1149IBM01149CCSID01149 CP01149 ebcdic-is-871+euro 
Cp1250windows-1250
Cp1251windows-1251
Cp1252windows-1252
Cp1253windows-1253
Cp1254windows-1254
Cp1255windows-1255
Cp1256windows-1256
Cp1257windows-1257
Cp1258windows-1258
Cp1381?
Cp1383?
Cp273IBM273csIBM273 
Cp277IBM277EBCDIC-CP-DK EBCDIC-CP-NO csIBM277 
Cp278IBM278CP278 ebcdic-cp-fi ebcdic-cp-se csIBM278 
Cp280IBM280ebcdic-cp-it csIBM280 
Cp284IBM284ebcdic-cp-es csIBM284 
Cp285IBM285ebcdic-cp-gb csIBM285 
Cp297IBM297ebcdic-cp-fr csIBM297 
Cp33722?
Cp420IBM420ebcdic-cp-ar1 csIBM420 
Cp424IBM424ebcdic-cp-he csIBM424 
Cp437IBM437437 csPC8CodePage437 
Cp500IBM500ebcdic-cp-be ebcdic-cp-ch csIBM500 
Cp737?
Cp775IBM775csPC775Baltic 
Cp838IBM-Thai
Cp850IBM850850 csPC850Multilingual 
Cp852IBM852852 csPCp852 
Cp855IBM855855 csIBM855 
Cp856?
Cp857IBM857857 csIBM857 
Cp858IBM00858CCSID00858 CP00858 PC-Multilingual-850+euro 
Cp860IBM860860 csIBM860 
Cp861IBM861861 cp-is csIBM861 
Cp862IBM862862 csPC862LatinHebrew 
Cp863IBM863863 csIBM863 
Cp864IBM864cp864 csIBM864 
Cp865IBM865865 csIBM865 
Cp866IBM866866 csIBM866 
Cp868IBM868cp-ar csIBM868 
Cp869IBM869cp-gr csIBM869 
Cp870IBM870ebcdic-cp-roece ebcdic-cp-yu csIBM870 
Cp871IBM871ebcdic-cp-is csIBM871 
Cp875?
Cp918IBM918ebcdic-cp-ar2 csIBM918 
Cp921?
Cp922?
Cp930?
Cp933?
Cp935?
Cp937?
Cp939?
Cp942?
Cp942C?
Cp943?
Cp943C?
Cp948?
Cp949?
Cp949C?
Cp950?
Cp964?
Cp970?
EUC_CNGB2312x-EUC-CN csGB2312 euccn euc-cn gb2312-80 gb2312-1980 CN-GB CN-GB-ISOIR165 
EUC_JPEUC-JPcsEUCPkdFmtJapanese Extended_UNIX_Code_Packed_Format_for_Japanese eucjis x-eucjp eucjp x-euc-jp 
EUC_JP_LINUX?
EUC_JP_Solaris?
EUC_KREUC-KRcsEUCKR ksc5601 5601 ksc5601_1987 ksc_5601 ksc5601-1987 ks_c_5601-1987 euckr 
EUC_TWEUC-TWx-EUC-TW cns11643 euctw 
GB18030GB18030gb18030-2000 
GBKwindows-936CP936 MS936 ms_936 x-mswin-936 
ISCII91?x-ISCII91 iscii 
ISO2022CNISO-2022-CN
ISO2022JPISO-2022-JPcsISO2022JP JIS jis_encoding csjisencoding 
ISO2022KRISO-2022-KRcsISO2022KR 
ISO2022_CN_CNS?
ISO2022_CN_GB?
ISO8859_1ISO-8859-1ISO_8859-1:1987 iso-ir-100 ISO_8859-1 latin1 l1 IBM819 CP819 csISOLatin1 8859_1 819 IBM-819 ISO8859-1 ISO_8859_1 
ISO8859_13ISO-8859-13
ISO8859_15ISO-8859-15ISO_8859-15 Latin-9 8859_15 csISOlatin9 IBM923 cp923 923 L9 IBM-923 ISO8859-15 LATIN9 LATIN0 csISOlatin0 ISO8859_15_FDIS 
ISO8859_2ISO-8859-2ISO_8859-2:1987 iso-ir-101 ISO_8859-2 latin2 l2 csISOLatin2 8859_2 iso8859_2 
ISO8859_3ISO-8859-3ISO_8859-3:1988 iso-ir-109 ISO_8859-3 latin3 l3 csISOLatin3 8859_3 
ISO8859_4ISO-8859-4ISO_8859-4:1988 iso-ir-110 ISO_8859-4 latin4 l4 csISOLatin4 8859_4 
ISO8859_5ISO-8859-5ISO_8859-5:1988 iso-ir-144 ISO_8859-5 cyrillic csISOLatinCyrillic 8859_5 
ISO8859_6ISO-8859-6ISO_8859-6:1987 iso-ir-127 ISO_8859-6 ECMA-114 ASMO-708 arabic csISOLatinArabic 8859_6 
ISO8859_7ISO-8859-7ISO_8859-7:1987 iso-ir-126 ISO_8859-7 ELOT_928 ECMA-118 greek greek8 csISOLatinGreek 8859_7 sun_eu_greek 
ISO8859_8ISO-8859-8ISO_8859-8:1988 iso-ir-138 ISO_8859-8 hebrew csISOLatinHebrew 8859_8 
ISO8859_9ISO-8859-9ISO_8859-9:1989 iso-ir-148 ISO_8859-9 latin5 l5 csISOLatin5 8859_9 
JISAutoDetect?
JIS_C6626-1983JIS_C6626-1983x-JIS0208 JIS0208 csISO87JISX0208 x0208 JIS_X0208-1983 iso-ir-87 
JIS_X0201JIS_X0201X0201 JIS0201 csHalfWidthKatakana 
JIS_X0212-1990JIS_X0212-1990iso-ir-159 x0212 JIS0212 csISO159JISX02121990 
KOI8_RKOI8-RcsKOI8R koi8 
MS874windows-874cp874 
MS932Windows-31Jwindows-932 csWindows31J x-ms-cp932 
MS949windows-949windows949 ms_949 x-windows-949 
MS950windows-950x-windows-950 
MS950_HKSCS
MacArabic?
MacCentralEurope?
MacCroatian?
MacCyrillic?
MacDingbat?
MacGreekMacGreek
MacHebrew?
MacIceland?
MacRomanMacRomanMacintosh MAC csMacintosh 
MacRomania?
MacSymbol?
MacThai?
MacTurkish?
MacUkraine?
SJISShift_JISMS_Kanji csShiftJIS shift-jis x-sjis pck 
TIS620TIS-620
UTF-16UTF-16UTF_16 
UTF8UTF-8
UnicodeBig?
UnicodeBigUnmarkedUTF-16BEX-UTF-16BE UTF_16BE ISO-10646-UCS-2 
UnicodeLittle?
UnicodeLittleUnmarkedUTF-16LEUTF_16LE X-UTF-16LE 
x-Johabjohabjohab cp1361 ms1361 ksc5601-1992 ksc5601_1992 
x-iso-8859-11?

 */
public class CharsetUtil {
    private static class Charset implements Comparable {
        private String canonical = null;
        private String mime = null;
        private String[] aliases = null;
        
        private Charset(String canonical, String mime, String[] aliases) {
            this.canonical = canonical;
            this.mime = mime;
            this.aliases = aliases;
        }
        public int compareTo(Charset c) {
            return this.canonical.compareTo(c.canonical);
        }
    }
    
    private static Charset[] JAVA_CHARSETS = {
        new Charset("ISO8859_1", "ISO-8859-1", 
                    new String[] {"ISO_8859-1:1987", "iso-ir-100", "ISO_8859-1", 
                                  "latin1", "l1", "IBM819", "CP819", 
                                  "csISOLatin1", "8859_1", "819", "IBM-819", 
                                  "ISO8859-1", "ISO_8859_1"}),
        new Charset("ISO8859_2", "ISO-8859-2", 
                    new String[] {"ISO_8859-2:1987", "iso-ir-101", "ISO_8859-2",  
                                  "latin2", "l2", "csISOLatin2", "8859_2", 
                                  "iso8859_2"}),
        new Charset("ISO8859_3", "ISO-8859-3", new String[] {"ISO_8859-3:1988", "iso-ir-109", "ISO_8859-3", "latin3", "l3", "csISOLatin3", "8859_3"}),
        new Charset("ISO8859_4", "ISO-8859-4", 
                    new String[] {"ISO_8859-4:1988", "iso-ir-110", "ISO_8859-4",
                                  "latin4", "l4", "csISOLatin4", "8859_4"}),
        new Charset("ISO8859_5", "ISO-8859-5", 
                    new String[] {"ISO_8859-5:1988", "iso-ir-144", "ISO_8859-5", 
                                  "cyrillic", "csISOLatinCyrillic", "8859_5"}),
        new Charset("ISO8859_6", "ISO-8859-6", new String[] {"ISO_8859-6:1987", "iso-ir-127", "ISO_8859-6", "ECMA-114", "ASMO-708", "arabic", "csISOLatinArabic", "8859_6"}),
        new Charset("ISO8859_7", "ISO-8859-7", 
                    new String[] {"ISO_8859-7:1987", "iso-ir-126", "ISO_8859-7", 
                                  "ELOT_928", "ECMA-118", "greek", "greek8", 
                                  "csISOLatinGreek", "8859_7", "sun_eu_greek"}),
        new Charset("ISO8859_8", "ISO-8859-8", new String[] {"ISO_8859-8:1988", "iso-ir-138", "ISO_8859-8", "hebrew", "csISOLatinHebrew", "8859_8"}),
        new Charset("ISO8859_9", "ISO-8859-9", 
                    new String[] {"ISO_8859-9:1989", "iso-ir-148", "ISO_8859-9",  
                                  "latin5", "l5", "csISOLatin5", "8859_9"}),
        new Charset("ISO8859_13", "ISO-8859-13", new String[] {}),
        new Charset("ISO8859_15", "ISO-8859-15", 
                    new String[] {"ISO_8859-15", "Latin-9", "8859_15", 
                                  "csISOlatin9", "IBM923", "cp923", "923", "L9",
                                  "IBM-923", "ISO8859-15", "LATIN9", "LATIN0", 
                                  "csISOlatin0", "ISO8859_15_FDIS"}),
        new Charset("KOI8_R", "KOI8-R", new String[] {"csKOI8R", "koi8"}),
        new Charset("ASCII", "US-ASCII", 
                    new String[] {"ANSI_X3.4-1968", "iso-ir-6", 
                                  "ANSI_X3.4-1986", "ISO_646.irv:1991", 
                                  "ISO646-US", "us", "IBM367", "cp367", 
                                  "csASCII", "ascii7", "646", "iso_646.irv:1983"}),
        new Charset("UTF8", "UTF-8", new String[] {}),
        new Charset("UTF-16", "UTF-16", new String[] {"UTF_16"}),
        new Charset("UnicodeBigUnmarked", "UTF-16BE", new String[] {"X-UTF-16BE", "UTF_16BE", "ISO-10646-UCS-2"}),
        new Charset("UnicodeLittleUnmarked", "UTF-16LE", new String[] {"UTF_16LE", "X-UTF-16LE"}),
        new Charset("Big5", "Big5", new String[] {"csBig5", "CN-Big5", "BIG-FIVE", "BIGFIVE"}),
        new Charset("Big5_HKSCS", "Big5-HKSCS", new String[] {"big5hkscs"}),
        new Charset("EUC_JP", "EUC-JP", 
                    new String[] {"csEUCPkdFmtJapanese", 
                              "Extended_UNIX_Code_Packed_Format_for_Japanese",
                              "eucjis", "x-eucjp", "eucjp", "x-euc-jp"}),
        new Charset("EUC_KR", "EUC-KR", 
                    new String[] {"csEUCKR", "ksc5601", "5601", "ksc5601_1987", 
                                  "ksc_5601", "ksc5601-1987", "ks_c_5601-1987", 
                                  "euckr"}),
        new Charset("GB18030", "GB18030", new String[] {"gb18030-2000"}),
        new Charset("EUC_CN", "GB2312", new String[] {"x-EUC-CN", "csGB2312", "euccn", "euc-cn", "gb2312-80", "gb2312-1980", "CN-GB", "CN-GB-ISOIR165"}),
        new Charset("GBK", "windows-936", new String[] {"CP936", "MS936", "ms_936", "x-mswin-936"}),
        new Charset("Cp037", "IBM037", new String[] {"ebcdic-cp-us", "ebcdic-cp-ca", "ebcdic-cp-wt", "ebcdic-cp-nl", "csIBM037"}),
        new Charset("Cp273", "IBM273", new String[] {"csIBM273"}),
        new Charset("Cp277", "IBM277", new String[] {"EBCDIC-CP-DK", "EBCDIC-CP-NO", "csIBM277"}),
        new Charset("Cp278", "IBM278", new String[] {"CP278", "ebcdic-cp-fi", "ebcdic-cp-se", "csIBM278"}),
        new Charset("Cp280", "IBM280", new String[] {"ebcdic-cp-it", "csIBM280"}),
        new Charset("Cp284", "IBM284", new String[] {"ebcdic-cp-es", "csIBM284"}),
        new Charset("Cp285", "IBM285", new String[] {"ebcdic-cp-gb", "csIBM285"}),
        new Charset("Cp297", "IBM297", new String[] {"ebcdic-cp-fr", "csIBM297"}),
        new Charset("Cp420", "IBM420", new String[] {"ebcdic-cp-ar1", "csIBM420"}),
        new Charset("Cp424", "IBM424", new String[] {"ebcdic-cp-he", "csIBM424"}),
        new Charset("Cp437", "IBM437", new String[] {"437", "csPC8CodePage437"}),
        new Charset("Cp500", "IBM500", new String[] {"ebcdic-cp-be", "ebcdic-cp-ch", "csIBM500"}),
        new Charset("Cp775", "IBM775", new String[] {"csPC775Baltic"}),
        new Charset("Cp838", "IBM-Thai", new String[] {}),
        new Charset("Cp850", "IBM850", new String[] {"850", "csPC850Multilingual"}),
        new Charset("Cp852", "IBM852", new String[] {"852", "csPCp852"}),
        new Charset("Cp855", "IBM855", new String[] {"855", "csIBM855"}),
        new Charset("Cp857", "IBM857", new String[] {"857", "csIBM857"}),
        new Charset("Cp858", "IBM00858", 
                new String[] {"CCSID00858", "CP00858", 
                              "PC-Multilingual-850+euro"}),
        new Charset("Cp860", "IBM860", new String[] {"860", "csIBM860"}),
        new Charset("Cp861", "IBM861", new String[] {"861", "cp-is", "csIBM861"}),
        new Charset("Cp862", "IBM862", new String[] {"862", "csPC862LatinHebrew"}),
        new Charset("Cp863", "IBM863", new String[] {"863", "csIBM863"}),
        new Charset("Cp864", "IBM864", new String[] {"cp864", "csIBM864"}),
        new Charset("Cp865", "IBM865", new String[] {"865", "csIBM865"}),
        new Charset("Cp866", "IBM866", new String[] {"866", "csIBM866"}),
        new Charset("Cp868", "IBM868", new String[] {"cp-ar", "csIBM868"}),
        new Charset("Cp869", "IBM869", new String[] {"cp-gr", "csIBM869"}),
        new Charset("Cp870", "IBM870", new String[] {"ebcdic-cp-roece", "ebcdic-cp-yu", "csIBM870"}),
        new Charset("Cp871", "IBM871", new String[] {"ebcdic-cp-is", "csIBM871"}),
        new Charset("Cp918", "IBM918", new String[] {"ebcdic-cp-ar2", "csIBM918"}),
        new Charset("Cp1026", "IBM1026", new String[] {"csIBM1026"}),
        new Charset("Cp1047", "IBM1047", new String[] {"IBM-1047"}),
        new Charset("Cp1140", "IBM01140", 
                    new String[] {"CCSID01140", "CP01140", 
                                  "ebcdic-us-37+euro"}),
        new Charset("Cp1141", "IBM01141", 
                    new String[] {"CCSID01141", "CP01141", 
                                  "ebcdic-de-273+euro"}),
        new Charset("Cp1142", "IBM01142", new String[] {"CCSID01142", "CP01142", "ebcdic-dk-277+euro", "ebcdic-no-277+euro"}),
        new Charset("Cp1143", "IBM01143", new String[] {"CCSID01143", "CP01143", "ebcdic-fi-278+euro", "ebcdic-se-278+euro"}),
        new Charset("Cp1144", "IBM01144", new String[] {"CCSID01144", "CP01144", "ebcdic-it-280+euro"}),
        new Charset("Cp1145", "IBM01145", new String[] {"CCSID01145", "CP01145", "ebcdic-es-284+euro"}),
        new Charset("Cp1146", "IBM01146", new String[] {"CCSID01146", "CP01146", "ebcdic-gb-285+euro"}),
        new Charset("Cp1147", "IBM01147", new String[] {"CCSID01147", "CP01147", "ebcdic-fr-297+euro"}),
        new Charset("Cp1148", "IBM01148", new String[] {"CCSID01148", "CP01148", "ebcdic-international-500+euro"}),
        new Charset("Cp1149", "IBM01149", new String[] {"CCSID01149", "CP01149", "ebcdic-is-871+euro"}),
        new Charset("Cp1250", "windows-1250", new String[] {}),
        new Charset("Cp1251", "windows-1251", new String[] {}),
        new Charset("Cp1252", "windows-1252", new String[] {}),
        new Charset("Cp1253", "windows-1253", new String[] {}),
        new Charset("Cp1254", "windows-1254", new String[] {}),
        new Charset("Cp1255", "windows-1255", new String[] {}),
        new Charset("Cp1256", "windows-1256", new String[] {}),
        new Charset("Cp1257", "windows-1257", new String[] {}),
        new Charset("Cp1258", "windows-1258", new String[] {}),
        new Charset("ISO2022CN", "ISO-2022-CN", new String[] {}),
        new Charset("ISO2022JP", "ISO-2022-JP", new String[] {"csISO2022JP", "JIS", "jis_encoding", "csjisencoding"}),
        new Charset("ISO2022KR", "ISO-2022-KR", new String[] {"csISO2022KR"}),
        new Charset("JIS_X0201", "JIS_X0201", new String[] {"X0201", "JIS0201", "csHalfWidthKatakana"}),
        new Charset("JIS_X0212-1990", "JIS_X0212-1990", new String[] {"iso-ir-159", "x0212", "JIS0212", "csISO159JISX02121990"}),
        new Charset("JIS_C6626-1983", "JIS_C6626-1983", new String[] {"x-JIS0208", "JIS0208", "csISO87JISX0208", "x0208", "JIS_X0208-1983", "iso-ir-87"}),
        new Charset("SJIS", "Shift_JIS", new String[] {"MS_Kanji", "csShiftJIS", "shift-jis", "x-sjis", "pck"}),
        new Charset("TIS620", "TIS-620", new String[] {}),
        new Charset("MS932", "Windows-31J", new String[] {"windows-932", "csWindows31J", "x-ms-cp932"}),
        new Charset("EUC_TW", "EUC-TW", new String[] {"x-EUC-TW", "cns11643", "euctw"}),
        new Charset("x-Johab", "johab", new String[] {"johab", "cp1361", "ms1361", "ksc5601-1992", "ksc5601_1992"}),
        new Charset("MS950_HKSCS", "", new String[] {}),
        new Charset("MS874", "windows-874", new String[] {"cp874"}),
        new Charset("MS949", "windows-949", new String[] {"windows949", "ms_949", "x-windows-949"}),
        new Charset("MS950", "windows-950", new String[] {"x-windows-950"}),
        new Charset("Cp737", null, new String[] {}),
        new Charset("Cp856", null, new String[] {}),
        new Charset("Cp875", null, new String[] {}),
        new Charset("Cp921", null, new String[] {}),
        new Charset("Cp922", null, new String[] {}),
        new Charset("Cp930", null, new String[] {}),
        new Charset("Cp933", null, new String[] {}),
        new Charset("Cp935", null, new String[] {}),
        new Charset("Cp937", null, new String[] {}),
        new Charset("Cp939", null, new String[] {}),
        new Charset("Cp942", null, new String[] {}),
        new Charset("Cp942C", null, new String[] {}),
        new Charset("Cp943", null, new String[] {}),
        new Charset("Cp943C", null, new String[] {}),
        new Charset("Cp948", null, new String[] {}),
        new Charset("Cp949", null, new String[] {}),
        new Charset("Cp949C", null, new String[] {}),
        new Charset("Cp950", null, new String[] {}),
        new Charset("Cp964", null, new String[] {}),
        new Charset("Cp970", null, new String[] {}),
        new Charset("Cp1006", null, new String[] {}),
        new Charset("Cp1025", null, new String[] {}),    
        new Charset("Cp1046", null, new String[] {}),
        new Charset("Cp1097", null, new String[] {}),
        new Charset("Cp1098", null, new String[] {}),
        new Charset("Cp1112", null, new String[] {}),
        new Charset("Cp1122", null, new String[] {}),
        new Charset("Cp1123", null, new String[] {}),
        new Charset("Cp1124", null, new String[] {}),
        new Charset("Cp1381", null, new String[] {}),
        new Charset("Cp1383", null, new String[] {}),
        new Charset("Cp33722", null, new String[] {}),
        new Charset("Big5_Solaris", null, new String[] {}),
        new Charset("EUC_JP_LINUX", null, new String[] {}),
        new Charset("EUC_JP_Solaris", null, new String[] {}),
        new Charset("ISCII91", null, new String[] {"x-ISCII91", "iscii"}),
        new Charset("ISO2022_CN_CNS", null, new String[] {}),
        new Charset("ISO2022_CN_GB", null, new String[] {}),
        new Charset("x-iso-8859-11", null, new String[] {}),
        new Charset("JISAutoDetect", null, new String[] {}),
        new Charset("MacArabic", null, new String[] {}),
        new Charset("MacCentralEurope", null, new String[] {}),
        new Charset("MacCroatian", null, new String[] {}),
        new Charset("MacCyrillic", null, new String[] {}),
        new Charset("MacDingbat", null, new String[] {}),
        new Charset("MacGreek", "MacGreek", new String[] {}),
        new Charset("MacHebrew", null, new String[] {}),
        new Charset("MacIceland", null, new String[] {}),
        new Charset("MacRoman", "MacRoman", new String[] {"Macintosh", "MAC", "csMacintosh"}),
        new Charset("MacRomania", null, new String[] {}),
        new Charset("MacSymbol", null, new String[] {}),
        new Charset("MacThai", null, new String[] {}),
        new Charset("MacTurkish", null, new String[] {}),
        new Charset("MacUkraine", null, new String[] {}),
        new Charset("UnicodeBig", null, new String[] {}),
        new Charset("UnicodeLittle", null, new String[] {})
    };
    /**
     * Contains the canonical names of character sets which can be used to 
     * decode bytes into Java chars.
     */
    private static SortedSet decodingSupported = null;
    
    /**
     * Contains the canonical names of character sets which can be used to 
     * encode Java chars into bytes.
     */
    private static SortedSet encodingSupported = null;
    
    /**
     * Maps character set names to Charset objects. All possible names of
     * a charset will be mapped to the Charset.
     */
    private static Map charsetMap = null;
    
    static {
        decodingSupported = new TreeSet();
        encodingSupported = new TreeSet();
        byte[] dummy = new byte[] {'d', 'u', 'm', 'm', 'y'};
        for (Charset c : JAVA_CHARSETS) {
            try {
                new String(dummy, c.canonical);
                decodingSupported.add(c.canonical.toLowerCase());
            } catch (UnsupportedOperationException e) {
            } catch (UnsupportedEncodingException e) {
            }
            try {
                "dummy".getBytes(c.canonical);
                encodingSupported.add(c.canonical.toLowerCase());
            } catch (UnsupportedOperationException e) {
            } catch (UnsupportedEncodingException e) {
            }
        }
        
        charsetMap = new HashMap();
        for (Charset c : JAVA_CHARSETS) {
            charsetMap.put(c.canonical.toLowerCase(), c);
            if (c.mime != null) {
                charsetMap.put(c.mime.toLowerCase(), c);
            }
            if (c.aliases != null) {
                for (String str : c.aliases) {
                    charsetMap.put(str.toLowerCase(), c);
                }
            }
        }
    }
    /** carriage return - line feed sequence */
    public static final String CRLF = "\r\n";
    /** US-ASCII CR, carriage return (13) */
    public static final int CR = '\r';
    /** US-ASCII LF, line feed (10) */
    public static final int LF = '\n';
    /** US-ASCII SP, space (32) */
    public static final int SP = ' ';
    /** US-ASCII HT, horizontal-tab (9) */
    public static final int HT = '\t';
    public static final java.nio.charset.Charset US_ASCII = java.nio.charset.Charset
            .forName("US-ASCII");
    public static final java.nio.charset.Charset ISO_8859_1 = java.nio.charset.Charset
            .forName("ISO-8859-1");
    public static final java.nio.charset.Charset UTF_8 = java.nio.charset.Charset
            .forName("UTF-8");
    public static final java.nio.charset.Charset DEFAULT_CHARSET = US_ASCII;
    /**
     * Returns true if the specified character falls into the US
     * ASCII character set (Unicode range 0000 to 007f).
     * 
     * @param ch
     *            character to test.
     * @return true if the specified character falls into the US
     *         ASCII character set, false otherwise.
     */
    public static boolean isASCII(char ch) {
        return (0xFF80 & ch) == 0;
    }
    /**
     * Returns true if the specified string consists entirely of
     * US ASCII characters.
     * 
     * @param s
     *            string to test.
     * @return true if the specified string consists entirely of
     *         US ASCII characters, false otherwise.
     */
    public static boolean isASCII(final String s) {
        if (s == null) {
            throw new IllegalArgumentException("String may not be null");
        }
        final int len = s.length();
        for (int i = 0; i < len; i++) {
            if (!isASCII(s.charAt(i))) {
                return false;
            }
        }
        return true;
    }
    /**
     * Returns true if the specified character is a whitespace
     * character (CR, LF, SP or HT).
     * 
     * @param ch
     *            character to test.
     * @return true if the specified character is a whitespace
     *         character, false otherwise.
     */
    public static boolean isWhitespace(char ch) {
        return ch == SP || ch == HT || ch == CR || ch == LF;
    }
    /**
     * Returns true if the specified string consists entirely of
     * whitespace characters.
     * 
     * @param s
     *            string to test.
     * @return true if the specified string consists entirely of
     *         whitespace characters, false otherwise.
     */
    public static boolean isWhitespace(final String s) {
        if (s == null) {
            throw new IllegalArgumentException("String may not be null");
        }
        final int len = s.length();
        for (int i = 0; i < len; i++) {
            if (!isWhitespace(s.charAt(i))) {
                return false;
            }
        }
        return true;
    }
    
    /**
     * Determines if the VM supports encoding (chars to bytes) the 
     * specified character set. NOTE: the given character set name may 
     * not be known to the VM even if this method returns true.
     * Use {@link #toJavaCharset(String)} to get the canonical Java character
     * set name.
     * 
     * @param charsetName the characters set name.
     * @return true if encoding is supported, false
     *         otherwise.
     */
    public static boolean isEncodingSupported(String charsetName) {
        return encodingSupported.contains(charsetName.toLowerCase());
    }
    
    /**
     * Determines if the VM supports decoding (bytes to chars) the 
     * specified character set. NOTE: the given character set name may 
     * not be known to the VM even if this method returns true.
     * Use {@link #toJavaCharset(String)} to get the canonical Java character
     * set name.
     * 
     * @param charsetName the characters set name.
     * @return true if decoding is supported, false
     *         otherwise.
     */
    public static boolean isDecodingSupported(String charsetName) {
        return decodingSupported.contains(charsetName.toLowerCase());
    }
    
    /**
     * Gets the preferred MIME character set name for the specified
     * character set or null if not known.
     * 
     * @param charsetName the character set name to look for.
     * @return the MIME preferred name or null if not known.
     */
    public static String toMimeCharset(String charsetName) {
        Charset c = charsetMap.get(charsetName.toLowerCase());
        if (c != null) {
            return c.mime;
        }
        return null;
    }
    
    /**
     * Gets the canonical Java character set name for the specified
     * character set or null if not known. This should be
     * called before doing any conversions using the Java API. NOTE:
     * you must use {@link #isEncodingSupported(String)} or
     * {@link #isDecodingSupported(String)} to make sure the returned
     * Java character set is supported by the current VM.
     * 
     * @param charsetName the character set name to look for.
     * @return the canonical Java name or null if not known.
     */
    public static String toJavaCharset(String charsetName) {
        Charset c = charsetMap.get(charsetName.toLowerCase());
        if (c != null) {
            return c.canonical;
        }
        return null;
    }
    public static java.nio.charset.Charset getCharset(String charsetName) {
        String defaultCharset = "ISO-8859-1";
        
        // Use the default chareset if given charset is null
        if(charsetName == null) charsetName = defaultCharset;
            
        try {
            return java.nio.charset.Charset.forName(charsetName);
        } catch (IllegalCharsetNameException e) {
            // Use default charset on exception 
            return java.nio.charset.Charset.forName(defaultCharset);
        } catch (UnsupportedCharsetException ex) {
            // Use default charset on exception
            return java.nio.charset.Charset.forName(defaultCharset);
        }
        
    }
    /*
     * Uncomment the code below and run the main method to regenerate the
     * Javadoc table above when the known charsets change. 
     */
    
    /*
    private static String dumpHtmlTable() {
        List l = new LinkedList(Arrays.asList(JAVA_CHARSETS));
        Collections.sort(l);
        StringBuilder sb = new StringBuilder();
        sb.append(" * \n");
        sb.append(" *     \n");
        sb.append(" *         \n");
        sb.append(" *         \n");
        sb.append(" *         \n");
        sb.append(" *     \n");
        for (Charset c : l) {
            sb.append(" *     \n");
            sb.append(" *         \n");
            sb.append(" *         \n");
            sb.append(" *         \n");
            sb.append(" *     \n");
        }
        sb.append(" * 
Canonical (Java) nameMIME preferredAliases
" + c.canonical + "" + (c.mime == null ? "?" : c.mime)+ "");
            for (int i = 0; c.aliases != null && i < c.aliases.length; i++) {
                sb.append(c.aliases[i] + " ");
            }
            sb.append("
\n");
        return sb.toString();
    }
    
    public static void main(String[] args) {
        System.out.println(dumpHtmlTable());
    }
    */
}