The escape character of html is then recognized by code
This article mainly explains "html escape characters and then code recognition", the content of the explanation is simple and clear, easy to learn and understand, the following please follow the editor's ideas slowly in depth, together to study and learn "html escape characters and then code recognition" bar!
Occasionally see characters such as & # 39; in the data, with the following characteristics
Begins with & # and ends with a string of numbers ending with;
Begins with & and ends with a string of characters that ends with
Such as the most common or equivalent
When the browser encounters these escape characters, it will escape back, but how can it be identified by the code? Org.apache.commons.lang.StringEscapeUtils.unescapeHtml provides a good explanation.
In the first case above, the number is in the middle, and the number (unicode) is converted directly into char.
In the second case, there are characters in the middle, so we can only look up the mapping table. Find the number corresponding to the characters in the mapping table and convert it to char. Look at the code at a glance.
See how HTML40 defines it.
Static {
HTML40=newEntities ()
FillWithHtml40Entities (HTML40)
}
StaticvoidfillWithHtml40Entities (Entitiesentities) {
Entities.addEntities (BASIC_ARRAY)
Entities.addEntities (ISO8859_1_ARRAY)
Entities.addEntities (HTML40_ARRAY)
}
Let's see what BASIC_ARRAY, ISO8859_1_ARRAY and HTML40_ARRAY are, respectively.
BASIC_ARRAY
PrivatestaticfinalString [] [] BASIC_ARRAY= {{"quot", "34"}, / / "- double-quote
{"amp", "38"}, / / &-ampersand
{"lt", "60"}, / /-greater-than
}
ISO8859_1_ARRAY
StaticfinalString [] [] ISO8859_1_ARRAY= {{"nbsp", "160"}, / / non-breakingspace
{"iexcl", "161"}, / / invertedexclamationmark
{"cent", "162"}, / / centsign
{"pound", "163"}, / / poundsign
{"curren", "164"}, / / currencysign
{"yen", "165"}, / / yensign=yuansign
{"brvbar", "166"}, / / brokenbar=brokenverticalbar
{"sect", "167"}, / / sectionsign
{"uml", "168"}, / / diaeresis=spacingdiaeresis
{"copy", "169"}, / / copyrightsign
{"ordf", "170"}, / / feminineordinalindicator
{"laquo", "171"}, / / left-pointingdoubleanglequotationmark=leftpointingguillemet
{"not", "172"}, / / notsign
{"shy", "173"}, / / softhyphen=discretionaryhyphen
{"reg", "174"}, / / reg-registeredtrademarksign
{"macr", "175"}, / / macron=spacingmacron=overline=APLoverbar
{"deg", "176"}, / / degreesign
{"plusmn", "177"}, / / plus-minussign=plus-or-minussign
{"sup2", "178"}, / / superscripttwo=superscriptdigittwo=squared
{"sup3", "179"}, / / superscriptthree=superscriptdigitthree=cubed
{"acute", "180"}, / / acuteaccent=spacingacute
{"micro", "181"}, / / microsign
{"para", "182"}, / / pilcrowsign=paragraphsign
{"middot", "183"}, / / middledot=Georgiancomma=Greekmiddledot
{"cedil", "184"}, / / cedilla=spacingcedilla
{"sup1", "185"}, / / superscriptone=superscriptdigitone
{"ordm", "186"}, / / masculineordinalindicator
{"raquo", "187"}, / / right-pointingdoubleanglequotationmark=rightpointingguillemet
{"frac14", "188"}, / / vulgarfractiononequarter=fractiononequarter
{"frac12", "189"}, / / vulgarfractiononehalf=fractiononehalf
{"frac34", "190"}, / / vulgarfractionthreequarters=fractionthreequarters
{"iquest", "191"}, / / invertedquestionmark=turnedquestionmark
{"Agrave", "192"}, / / uppercaseA,graveaccent
{"Aacute", "193"}, / / Aacute-uppercaseA,acuteaccent
{"Acirc", "194"}, / / uppercaseA,circumflexaccent
{"Atilde", "195"}, / / Atilde-uppercaseA,tilde
{"Auml", "196"}, / / uppercaseA,umlaut
{"Aring", "197"}, / / Aring-uppercaseA,ring
{"AElig", "198"}, / / uppercaseAE
{"Ccedil", "199"}, / / uppercaseC,cedilla
{"Egrave", "200"}, / / Egrave-uppercaseE,graveaccent
{"Eacute", "201"}, / / uppercaseE,acuteaccent
{"Ecirc", "202"}, / / uppercaseE,circumflexaccent
{"Euml", "203"}, / / uppercaseE,umlaut
{"Igrave", "204"}, / / uppercaseI,graveaccent
{"Iacute", "205"}, / / uppercaseI,acuteaccent
{"Icirc", "206"}, / / uppercaseI,circumflexaccent
{"Iuml", "207"}, / / uppercaseI,umlaut
{"ETH", "208"}, / / uppercaseEth,Icelandic
{"Ntilde", "209"}, / / uppercaseN,tilde
{"Ograve", "210"}, / / uppercaseO,graveaccent
{"Oacute", "211"}, / / uppercaseO,acuteaccent
{"Ocirc", "212"}, / / uppercaseO,circumflexaccent
{"Otilde", "213"}, / / uppercaseO,tilde
{"Ouml", "214"}, / / Ouml-uppercaseO,umlaut
{"times", "215"}, / / multiplicationsign
{"Oslash", "216"}, / / Oslash-uppercaseO,slash
{"Ugrave", "217"}, / / uppercaseU,graveaccent
{"Uacute", "218"}, / / uppercaseU,acuteaccent
{"Ucirc", "219"}, / / uppercaseU,circumflexaccent
{"Uuml", "220"}, / / uppercaseU,umlaut
{"Yacute", "221"}, / / Yacute-uppercaseY,acuteaccent
{"THORN", "222"}, / / THORN-uppercaseTHORN,Icelandic
{"szlig", "223"}, / / lowercasesharps,German
{"agrave", "224"}, / / lowercasea,graveaccent
{"aacute", "225"}, / / aacute-lowercasea,acuteaccent
{"acirc", "226"}, / / acirc-lowercasea,circumflexaccent
{"atilde", "227"}, / / lowercasea,tilde
{"auml", "228"}, / / lowercasea,umlaut
{"aring", "229"}, / / lowercasea,ring
{"aelig", "230"}, / / lowercaseae
{"ccedil", "231"}, / / please-lowercasec,cedilla
{"egrave", "232"}, / / egrave-lowercasee,graveaccent
{"eacute", "233"}, / / eacute-lowercasee,acuteaccent
{"ecirc", "234"}, / / lowercasee,circumflexaccent
{"euml", "235"}, / / euml-lowercasee,umlaut
{"igrave", "236"}, / / lowercasei,graveaccent
{"iacute", "237"}, / / lowercasei,acuteaccent
{"icirc", "238"}, / / lowercasei,circumflexaccent
{"iuml", "239"}, / / lowercasei,umlaut
{"eth", "240"}, / / eth-lowercaseeth,Icelandic
{"ntilde", "241"}, / / ntilde-lowercasen,tilde
{"ograve", "242"}, / / lowercaseo,graveaccent
{"oacute", "243"}, / / oacute-lowercaseo,acuteaccent
{"ocirc", "244"}, / / ocirc-lowercaseo,circumflexaccent
{"otilde", "245"}, / / otilde-lowercaseo,tilde
{"ouml", "246"}, / / ouml-lowercaseo,umlaut
{"divide", "247"}, / / divisionsign
{"oslash", "248"}, / / oslash-lowercaseo,slash
{"ugrave", "249"}, / / ugrave-lowercaseu,graveaccent
{"uacute", "250"}, / / lowercaseu,acuteaccent
{"ucirc", "251"}, / / ucirc-lowercaseu,circumflexaccent
{"uuml", "252"}, / / uuml-lowercaseu,umlaut
{"yacute", "253"}, / / yacute-lowercasey,acuteaccent
{"thorn", "254"}, / / thorn-lowercasethorn,Icelandic
{"yuml", "255"}, / / lowercasey,umlaut
}
HTML40_ARRAY
StaticfinalString [] [] HTML40_ARRAY= {
/ /
{"fnof", "402"}, / / latinsmallfwithhook=function=florin,U+0192ISOtech-- >
/ /
{"Alpha", "913"}, / / greekcapitalletteralpha,U+0391-- >
{"Beta", "914"}, / / greekcapitalletterbeta,U+0392-- >
{"Gamma", "915"}, / / greekcapitallettergamma,U+0393ISOgrk3-- >
{"Delta", "916"}, / / greekcapitalletterdelta,U+0394ISOgrk3-- >
{"Epsilon", "917"}, / / greekcapitalletterepsilon,U+0395-- >
{"Zeta", "918"}, / / greekcapitalletterzeta,U+0396-- >
{"Eta", "919"}, / / greekcapitallettereta,U+0397-- >
{"Theta", "920"}, / / greekcapitallettertheta,U+0398ISOgrk3-- >
{"Iota", "921"}, / / greekcapitalletteriota,U+0399-- >
{"Kappa", "922"}, / / greekcapitalletterkappa,U+039A-- >
{"Lambda", "923"}, / / greekcapitalletterlambda,U+039BISOgrk3-- >
{"Mu", "924"}, / / greekcapitallettermu,U+039C-- >
{"Nu", "925"}, / / greekcapitalletternu,U+039D-- >
{"Xi", "926"}, / / greekcapitalletterxi,U+039EISOgrk3-- >
{"Omicron", "927"}, / / greekcapitalletteromicron,U+039F-- >
{"Pi", "928"}, / / greekcapitalletterpi,U+03A0ISOgrk3-- >
{"Rho", "929"}, / / greekcapitalletterrho,U+03A1-- >
/ /
{"Sigma", "931"}, / / greekcapitallettersigma,U+03A3ISOgrk3-- >
{"Tau", "932"}, / / greekcapitallettertau,U+03A4-- >
{"Upsilon", "933"}, / / greekcapitalletterupsilon,U+03A5ISOgrk3-- >
{"Phi", "934"}, / / greekcapitalletterphi,U+03A6ISOgrk3-- >
{"Chi", "935"}, / / greekcapitalletterchi,U+03A7-- >
{"Psi", "936"}, / / greekcapitalletterpsi,U+03A8ISOgrk3-- >
{"Omega", "937"}, / / greekcapitalletteromega,U+03A9ISOgrk3-- >
{"alpha", "945"}, / / greeksmallletteralpha,U+03B1ISOgrk3-- >
{"beta", "946"}, / / greeksmallletterbeta,U+03B2ISOgrk3-- >
{"gamma", "947"}, / / greeksmalllettergamma,U+03B3ISOgrk3-- >
{"delta", "948"}, / / greeksmallletterdelta,U+03B4ISOgrk3-- >
{"epsilon", "949"}, / / greeksmallletterepsilon,U+03B5ISOgrk3-- >
{"zeta", "950"}, / / greeksmallletterzeta,U+03B6ISOgrk3-- >
{"eta", "951"}, / / greeksmalllettereta,U+03B7ISOgrk3-- >
{"theta", "952"}, / / greeksmalllettertheta,U+03B8ISOgrk3-- >
{"iota", "953"}, / / greeksmallletteriota,U+03B9ISOgrk3-- >
{"kappa", "954"}, / / greeksmallletterkappa,U+03BAISOgrk3-- >
{"lambda", "955"}, / / greeksmallletterlambda,U+03BBISOgrk3-- >
{"mu", "956"}, / / greeksmalllettermu,U+03BCISOgrk3-- >
{"nu", "957"}, / / greeksmallletternu,U+03BDISOgrk3-- >
{"xi", "958"}, / / greeksmallletterxi,U+03BEISOgrk3-- >
{"omicron", "959"}, / / greeksmallletteromicron,U+03BFNEW-- >
{"pi", "960"}, / / greeksmallletterpi,U+03C0ISOgrk3-- >
{"rho", "961"}, / / greeksmallletterrho,U+03C1ISOgrk3-- >
{"sigmaf", "962"}, / / greeksmallletterfinalsigma,U+03C2ISOgrk3-- >
{"sigma", "963"}, / / greeksmalllettersigma,U+03C3ISOgrk3-- >
{"tau", "964"}, / / greeksmalllettertau,U+03C4ISOgrk3-- >
{"upsilon", "965"}, / / greeksmallletterupsilon,U+03C5ISOgrk3-- >
{"phi", "966"}, / / greeksmallletterphi,U+03C6ISOgrk3-- >
{"chi", "967"}, / / greeksmallletterchi,U+03C7ISOgrk3-- >
{"psi", "968"}, / / greeksmallletterpsi,U+03C8ISOgrk3-- >
{"omega", "969"}, / / greeksmallletteromega,U+03C9ISOgrk3-- >
{"thetasym", "977"}, / / greeksmallletterthetasymbol,U+03D1NEW-- >
{"upsih", "978"}, / / greekupsilonwithhooksymbol,U+03D2NEW-- >
{"piv", "982"}, / / greekpisymbol,U+03D6ISOgrk3-- >
/ /
{"bull", "8226"}, / / bullet=blacksmallcircle,U+2022ISOpub-- >
/ /
{"hellip", "8230"}, / / horizontalellipsis=threedotleader,U+2026ISOpub-- >
{"prime", "8242"}, / / prime=minutes=feet,U+2032ISOtech-- >
{"Prime", "8243"}, / / doubleprime=seconds=inches,U+2033ISOtech-- >
{"oline", "8254"}, / / overline=spacingoverscore,U+203ENEW-- >
{"frasl", "8260"}, / / fractionslash,U+2044NEW-- >
/ /
{"weierp", "8472"}, / / scriptcapitalP=powerset=Weierstrassp,U+2118ISOamso-- >
{"image", "8465"}, / / blacklettercapitalI=imaginarypart,U+2111ISOamso-- >
{"real", "8476"}, / / blacklettercapitalR=realpartsymbol,U+211CISOamso-- >
{"trade", "8482"}, / / trademarksign,U+2122ISOnum-- >
{"alefsym", "8501"}, / / alefsymbol=firsttransfinitecardinal,U+2135NEW-- >
/ /
/ /
{"larr", "8592"}, / / leftwardsarrow,U+2190ISOnum-- >
{"uarr", "8593"}, / / upwardsarrow,U+2191ISOnum-- >
{"rarr", "8594"}, / / rightwardsarrow,U+2192ISOnum-- >
{"darr", "8595"}, / / downwardsarrow,U+2193ISOnum-- >
{"harr", "8596"}, / / leftrightarrow,U+2194ISOamsa-- >
{"crarr", "8629"}, / / downwardsarrowwithcornerleftwards=carriagereturn,U+21B5NEW-- >
{"lArr", "8656"}, / / leftwardsdoublearrow,U+21D0ISOtech-- >
/ /
{"uArr", "8657"}, / / upwardsdoublearrow,U+21D1ISOamsa-- >
{"rArr", "8658"}, / / rightwardsdoublearrow,U+21D2ISOtech-- >
/ /
{"dArr", "8659"}, / / downwardsdoublearrow,U+21D3ISOamsa-- >
{"hArr", "8660"}, / / leftrightdoublearrow,U+21D4ISOamsa-- >
/ /
{"forall", "8704"}, / / forall,U+2200ISOtech-- >
{"part", "8706"}, / / partialdifferential,U+2202ISOtech-- >
{"exist", "8707"}, / / thereexists,U+2203ISOtech-- >
{"empty", "8709"}, / / emptyset=nullset=diameter,U+2205ISOamso-- >
{"nabla", "8711"}, / / nabla=backwarddifference,U+2207ISOtech-- >
{"isin", "8712"}, / / elementof,U+2208ISOtech-- >
{"notin", "8713"}, / / notanelementof,U+2209ISOtech-- >
{"ni", "8715"}, / / containsasmember,U+220BISOtech-- >
/ /
{"prod", "8719"}, / / 220FISOamsbyl->
/ /
{"sum", "8721"}, / / copyright 2211 ISOamsb->
/ /
{"minus", "8722"}, / / minussign,U+2212ISOtech-- >
{"lowast", "8727"}, / / asteriskoperator,U+2217ISOtech-- >
{"radic", "8730"}, / / squareroot=radicalsign,U+221AISOtech-- >
{"prop", "8733"}, / / proportionalto,U+221DISOtech-- >
{"infin", "8734"}, / / infinity,U+221EISOtech-- >
{"ang", "8736"}, / / angle,U+2220ISOamso-- >
{"and", "8743"}, / / logicaland=wedge,U+2227ISOtech-- >
{"or", "8744"}, / / logicalor=vee,U+2228ISOtech-- >
{"cap", "8745"}, / / intersection=cap,U+2229ISOtech-- >
{"cup", "8746"}, / / union=cup,U+222AISOtech-- >
{"int", "8747"}, / / integral,U+222BISOtech-- >
{"there4", "8756"}, / / therefore,U+2234ISOtech-- >
{"sim", "8764"}, / / tildeoperator=varieswith=similarto,U+223CISOtech-- >
/ /
{"cong", "8773"}, / / approximatelyequalto,U+2245ISOtech-- >
{"asymp", "8776"}, / / almostequalto=asymptoticto,U+2248ISOamsr-- >
{"ne", "8800"}, / / notequalto,U+2260ISOtech-- >
{"equiv", "8801"}, / / identicalto,U+2261ISOtech-- >
{"le", "8804"}, / / less-thanorequalto,U+2264ISOtech-- >
{"ge", "8805"}, / / greater-thanorequalto,U+2265ISOtech-- >
{"sub", "8834"}, / / subsetof,U+2282ISOtech-- >
{"sup", "8835"}, / / supersetof,U+2283ISOtech-- >
/ /
