转义字符html识别吗,HTML_谈谈html转义字符如何通过代码识别，偶尔会在数据中看到诸如 - phpStudy...

谈谈html转义字符如何通过代码识别

偶尔会在数据中看到诸如' 这样的字符，特征如下

以开头，中间是一串数字，以；结尾

以&开头，中间一串字符，以；结尾

比如最常见的 或者等价的 

浏览器遇到这些转义符，会转义回来，但如何通过代码识别？ org.apache.commons.lang.StringEscapeUtils.unescapeHtml提供了很好的说明

遇到上面的第一种情况，中间是数字的，直接将数字(unicode)转为char

遇到第二情况，中间是字符，只能查映射表了,从映射表中找到字符对应的数字再转换为char 看看代码就一目了然了

看看HTML40如何定义的

复制代码代码如下:

static {

HTML40 = new Entities();

fillWithHtml40Entities(HTML40);

}

static void fillWithHtml40Entities(Entities entities) {

entities.addEntities(BASIC_ARRAY);

entities.addEntities(ISO8859_1_ARRAY);

entities.addEntities(HTML40_ARRAY);

}

再看看BASIC_ARRAY、ISO8859_1_ARRAY、HTML40_ARRAY 分别是什么

BASIC_ARRAY

复制代码代码如下:

private static final String[][] BASIC_ARRAY = {{"quot", "34"}, // " - double-quote

{"amp", "38"}, // & - ampersand

{"lt", "60"}, // < - less-than

{"gt", "62"}, // > - greater-than

};

ISO8859_1_ARRAY

复制代码代码如下:

static final String[][] ISO8859_1_ARRAY = {{"nbsp", "160"}, // non-breaking space

{"iexcl", "161"}, // inverted exclamation mark

{"cent", "162"}, // cent sign

{"pound", "163"}, // pound sign

{"curren", "164"}, // currency sign

{"yen", "165"}, // yen sign = yuan sign

{"brvbar", "166"}, // broken bar = broken vertical bar

{"sect", "167"}, // section sign

{"uml", "168"}, // diaeresis = spacing diaeresis

{"copy", "169"}, // � - copyright sign

{"ordf", "170"}, // feminine ordinal indicator

{"laquo", "171"}, // left-pointing double angle quotation mark = left pointing guillemet

{"not", "172"}, // not sign

{"shy", "173"}, // soft hyphen = discretionary hyphen

{"reg", "174"}, // � - registered trademark sign

{"macr", "175"}, // macron = spacing macron = overline = APL overbar

{"deg", "176"}, // degree sign

{"plusmn", "177"}, // plus-minus sign = plus-or-minus sign

{"sup2", "178"}, // superscript two = superscript digit two = squared

{"sup3", "179"}, // superscript three = superscript digit three = cubed

{"acute", "180"}, // acute accent = spacing acute

{"micro", "181"}, // micro sign

{"para", "182"}, // pilcrow sign = paragraph sign

{"middot", "183"}, // middle dot = Georgian comma = Greek middle dot

{"cedil", "184"}, // cedilla = spacing cedilla

{"sup1", "185"}, // superscript one = superscript digit one

{"ordm", "186"}, // masculine ordinal indicator

{"raquo", "187"}, // right-pointing double angle quotation mark = right pointing guillemet

{"frac14", "188"}, // vulgar fraction one quarter = fraction one quarter

{"frac12", "189"}, // vulgar fraction one half = fraction one half

{"frac34", "190"}, // vulgar fraction three quarters = fraction three quarters

{"iquest", "191"}, // inverted question mark = turned question mark

{"Agrave", "192"}, // � - uppercase A, grave accent

{"Aacute", "193"}, // � - uppercase A, acute accent

{"Acirc", "194"}, // � - uppercase A, circumflex accent

{"Atilde", "195"}, // � - uppercase A, tilde

{"Auml", "196"}, // � - uppercase A, umlaut

{"Aring", "197"}, // � - uppercase A, ring

{"AElig", "198"}, // � - uppercase AE

{"Ccedil", "199"}, // � - uppercase C, cedilla

{"Egrave", "200"}, // � - uppercase E, grave accent

{"Eacute", "201"}, // � - uppercase E, acute accent

{"Ecirc", "202"}, // � - uppercase E, circumflex accent

{"Euml", "203"}, // � - uppercase E, umlaut

{"Igrave", "204"}, // � - uppercase I, grave accent

{"Iacute", "205"}, // � - uppercase I, acute accent

{"Icirc", "206"}, // � - uppercase I, circumflex accent

{"Iuml", "207"}, // � - uppercase I, umlaut

{"ETH", "208"}, // � - uppercase Eth, Icelandic

{"Ntilde", "209"}, // � - uppercase N, tilde

{"Ograve", "210"}, // � - uppercase O, grave accent

{"Oacute", "211"}, // � - uppercase O, acute accent

{"Ocirc", "212"}, // � - uppercase O, circumflex accent

{"Otilde", "213"}, // � - uppercase O, tilde

{"Ouml", "214"}, // � - uppercase O, umlaut

{"times", "215"}, // multiplication sign

{"Oslash", "216"}, // � - uppercase O, slash

{"Ugrave", "217"}, // � - uppercase U, grave accent

{"Uacute", "218"}, // � - uppercase U, acute accent

{"Ucirc", "219"}, // � - uppercase U, circumflex accent

{"Uuml", "220"}, // � - uppercase U, umlaut

{"Yacute", "221"}, // � - uppercase Y, acute accent

{"THORN", "222"}, // � - uppercase THORN, Icelandic

{"szlig", "223"}, // � - lowercase sharps, German

{"agrave", "224"}, // � - lowercase a, grave accent

{"aacute", "225"}, // � - lowercase a, acute accent

{"acirc", "226"}, // � - lowercase a, circumflex accent

{"atilde", "227"}, // � - lowercase a, tilde

{"auml", "228"}, // � - lowercase a, umlaut

{"aring", "229"}, // � - lowercase a, ring

{"aelig", "230"}, // � - lowercase ae

{"ccedil", "231"}, // � - lowercase c, cedilla

{"egrave", "232"}, // � - lowercase e, grave accent

{"eacute", "233"}, // � - lowercase e, acute accent

{"ecirc", "234"}, // � - lowercase e, circumflex accent

{"euml", "235"}, // � - lowercase e, umlaut

{"igrave", "236"}, // � - lowercase i, grave accent

{"iacute", "237"}, // � - lowercase i, acute accent

{"icirc", "238"}, // � - lowercase i, circumflex accent

{"iuml", "239"}, // � - lowercase i, umlaut

{"eth", "240"}, // � - lowercase eth, Icelandic

{"ntilde", "241"}, // � - lowercase n, tilde

{"ograve", "242"}, // � - lowercase o, grave accent

{"oacute", "243"}, // � - lowercase o, acute accent

{"ocirc", "244"}, // � - lowercase o, circumflex accent

{"otilde", "245"}, // � - lowercase o, tilde

{"ouml", "246"}, // � - lowercase o, umlaut

{"divide", "247"}, // division sign

{"oslash", "248"}, // � - lowercase o, slash

{"ugrave", "249"}, // � - lowercase u, grave accent

{"uacute", "250"}, // � - lowercase u, acute accent

{"ucirc", "251"}, // � - lowercase u, circumflex accent

{"uuml", "252"}, // � - lowercase u, umlaut

{"yacute", "253"}, // � - lowercase y, acute accent

{"thorn", "254"}, // � - lowercase thorn, Icelandic

{"yuml", "255"}, // � - lowercase y, umlaut

};

HTML40_ARRAY

复制代码代码如下:

static final String[][] HTML40_ARRAY = {

//

{"fnof", "402"}, // latin small f with hook = function= florin, U+0192 ISOtech -->

//

{"Alpha", "913"}, // greek capital letter alpha, U+0391 -->

{"Beta", "914"}, // greek capital letter beta, U+0392 -->

{"Gamma", "915"}, // greek capital letter gamma,U+0393 ISOgrk3 -->

{"Delta", "916"}, // greek capital letter delta,U+0394 ISOgrk3 -->

{"Epsilon", "917"}, // greek capital letter epsilon, U+0395 -->

{"Zeta", "918"}, // greek capital letter zeta, U+0396 -->

{"Eta", "919"}, // greek capital letter eta, U+0397 -->

{"Theta", "920"}, // greek capital letter theta,U+0398 ISOgrk3 -->

{"Iota", "921"}, // greek capital letter iota, U+0399 -->

{"Kappa", "922"}, // greek capital letter kappa, U+039A -->

{"Lambda", "923"}, // greek capital letter lambda,U+039B ISOgrk3 -->

{"Mu", "924"}, // greek capital letter mu, U+039C -->

{"Nu", "925"}, // greek capital letter nu, U+039D -->

{"Xi", "926"}, // greek capital letter xi, U+039E ISOgrk3 -->

{"Omicron", "927"}, // greek capital letter omicron, U+039F -->

{"Pi", "928"}, // greek capital letter pi, U+03A0 ISOgrk3 -->

{"Rho", "929"}, // greek capital letter rho, U+03A1 -->

//

{"Sigma", "931"}, // greek capital letter sigma,U+03A3 ISOgrk3 -->

{"Tau", "932"}, // greek capital letter tau, U+03A4 -->

{"Upsilon", "933"}, // greek capital letter upsilon,U+03A5 ISOgrk3 -->

{"Phi", "934"}, // greek capital letter phi,U+03A6 ISOgrk3 -->

{"Chi", "935"}, // greek capital letter chi, U+03A7 -->

{"Psi", "936"}, // greek capital letter psi,U+03A8 ISOgrk3 -->

{"Omega", "937"}, // greek capital letter omega,U+03A9 ISOgrk3 -->

{"alpha", "945"}, // greek small letter alpha,U+03B1 ISOgrk3 -->

{"beta", "946"}, // greek small letter beta, U+03B2 ISOgrk3 -->

{"gamma", "947"}, // greek small letter gamma,U+03B3 ISOgrk3 -->

{"delta", "948"}, // greek small letter delta,U+03B4 ISOgrk3 -->

{"epsilon", "949"}, // greek small letter epsilon,U+03B5 ISOgrk3 -->

{"zeta", "950"}, // greek small letter zeta, U+03B6 ISOgrk3 -->

{"eta", "951"}, // greek small letter eta, U+03B7 ISOgrk3 -->

{"theta", "952"}, // greek small letter theta,U+03B8 ISOgrk3 -->

{"iota", "953"}, // greek small letter iota, U+03B9 ISOgrk3 -->

{"kappa", "954"}, // greek small letter kappa,U+03BA ISOgrk3 -->

{"lambda", "955"}, // greek small letter lambda,U+03BB ISOgrk3 -->

{"mu", "956"}, // greek small letter mu, U+03BC ISOgrk3 -->

{"nu", "957"}, // greek small letter nu, U+03BD ISOgrk3 -->

{"xi", "958"}, // greek small letter xi, U+03BE ISOgrk3 -->

{"omicron", "959"}, // greek small letter omicron, U+03BF NEW -->

{"pi", "960"}, // greek small letter pi, U+03C0 ISOgrk3 -->

{"rho", "961"}, // greek small letter rho, U+03C1 ISOgrk3 -->

{"sigmaf", "962"}, // greek small letter final sigma,U+03C2 ISOgrk3 -->

{"sigma", "963"}, // greek small letter sigma,U+03C3 ISOgrk3 -->

{"tau", "964"}, // greek small letter tau, U+03C4 ISOgrk3 -->

{"upsilon", "965"}, // greek small letter upsilon,U+03C5 ISOgrk3 -->

{"phi", "966"}, // greek small letter phi, U+03C6 ISOgrk3 -->

{"chi", "967"}, // greek small letter chi, U+03C7 ISOgrk3 -->

{"psi", "968"}, // greek small letter psi, U+03C8 ISOgrk3 -->

{"omega", "969"}, // greek small letter omega,U+03C9 ISOgrk3 -->

{"thetasym", "977"}, // greek small letter theta symbol,U+03D1 NEW -->

{"upsih", "978"}, // greek upsilon with hook symbol,U+03D2 NEW -->

{"piv", "982"}, // greek pi symbol, U+03D6 ISOgrk3 -->

//

{"bull", "8226"}, // bullet = black small circle,U+2022 ISOpub -->

//

{"hellip", "8230"}, // horizontal ellipsis = three dot leader,U+2026 ISOpub -->

{"prime", "8242"}, // prime = minutes = feet, U+2032 ISOtech -->

{"Prime", "8243"}, // double prime = seconds = inches,U+2033 ISOtech -->

{"oline", "8254"}, // overline = spacing overscore,U+203E NEW -->

{"frasl", "8260"}, // fraction slash, U+2044 NEW -->

//

{"weierp", "8472"}, // script capital P = power set= Weierstrass p, U+2118 ISOamso -->

{"image", "8465"}, // blackletter capital I = imaginary part,U+2111 ISOamso -->

{"real", "8476"}, // blackletter capital R = real part symbol,U+211C ISOamso -->

{"trade", "8482"}, // trade mark sign, U+2122 ISOnum -->

{"alefsym", "8501"}, // alef symbol = first transfinite cardinal,U+2135 NEW -->

//

//

{"larr", "8592"}, // leftwards arrow, U+2190 ISOnum -->

{"uarr", "8593"}, // upwards arrow, U+2191 ISOnum-->

{"rarr", "8594"}, // rightwards arrow, U+2192 ISOnum -->

{"darr", "8595"}, // downwards arrow, U+2193 ISOnum -->

{"harr", "8596"}, // left right arrow, U+2194 ISOamsa -->

{"crarr", "8629"}, // downwards arrow with corner leftwards= carriage return, U+21B5 NEW -->

{"lArr", "8656"}, // leftwards double arrow, U+21D0 ISOtech -->

//

{"uArr", "8657"}, // upwards double arrow, U+21D1 ISOamsa -->

{"rArr", "8658"}, // rightwards double arrow,U+21D2 ISOtech -->

//

{"dArr", "8659"}, // downwards double arrow, U+21D3 ISOamsa -->

{"hArr", "8660"}, // left right double arrow,U+21D4 ISOamsa -->

//

{"forall", "8704"}, // for all, U+2200 ISOtech -->

{"part", "8706"}, // partial differential, U+2202 ISOtech -->

{"exist", "8707"}, // there exists, U+2203 ISOtech -->

{"empty", "8709"}, // empty set = null set = diameter,U+2205 ISOamso -->

{"nabla", "8711"}, // nabla = backward difference,U+2207 ISOtech -->

{"isin", "8712"}, // element of, U+2208 ISOtech -->

{"notin", "8713"}, // not an element of, U+2209 ISOtech -->

{"ni", "8715"}, // contains as member, U+220B ISOtech -->

//

{"prod", "8719"}, // n-ary product = product sign,U+220F ISOamsb -->

//

{"sum", "8721"}, // n-ary summation, U+2211 ISOamsb -->

//

{"minus", "8722"}, // minus sign, U+2212 ISOtech -->

{"lowast", "8727"}, // asterisk operator, U+2217 ISOtech -->

{"radic", "8730"}, // square root = radical sign,U+221A ISOtech -->

{"prop", "8733"}, // proportional to, U+221D ISOtech -->

{"infin", "8734"}, // infinity, U+221E ISOtech -->

{"ang", "8736"}, // angle, U+2220 ISOamso -->

{"and", "8743"}, // logical and = wedge, U+2227 ISOtech -->

{"or", "8744"}, // logical or = vee, U+2228 ISOtech -->

{"cap", "8745"}, // intersection = cap, U+2229 ISOtech -->

{"cup", "8746"}, // union = cup, U+222A ISOtech -->

{"int", "8747"}, // integral, U+222B ISOtech -->

{"there4", "8756"}, // therefore, U+2234 ISOtech -->

{"sim", "8764"}, // tilde operator = varies with = similar to,U+223C ISOtech -->

//

{"cong", "8773"}, // approximately equal to, U+2245 ISOtech -->

{"asymp", "8776"}, // almost equal to = asymptotic to,U+2248 ISOamsr -->

{"ne", "8800"}, // not equal to, U+2260 ISOtech -->

{"equiv", "8801"}, // identical to, U+2261 ISOtech -->

{"le", "8804"}, // less-than or equal to, U+2264 ISOtech -->

{"ge", "8805"}, // greater-than or equal to,U+2265 ISOtech -->

{"sub", "8834"}, // subset of, U+2282 ISOtech -->

{"sup", "8835"}, // superset of, U+2283 ISOtech -->

//

// not a subset of, U+2284 ISOamsn -->

{"sube", "8838"}, // subset of or equal to, U+2286 ISOtech -->

{"supe", "8839"}, // superset of or equal to,U+2287 ISOtech -->

{"oplus", "8853"}, // circled plus = direct sum,U+2295 ISOamsb -->

{"otimes", "8855"}, // circled times = vector product,U+2297 ISOamsb -->

{"perp", "8869"}, // up tack = orthogonal to = perpendicular,U+22A5 ISOtech -->

{"sdot", "8901"}, // dot operator, U+22C5 ISOamsb -->

//

//

{"lceil", "8968"}, // left ceiling = apl upstile,U+2308 ISOamsc -->

{"rceil", "8969"}, // right ceiling, U+2309 ISOamsc -->

{"lfloor", "8970"}, // left floor = apl downstile,U+230A ISOamsc -->

{"rfloor", "8971"}, // right floor, U+230B ISOamsc -->

{"lang", "9001"}, // left-pointing angle bracket = bra,U+2329 ISOtech -->

//

{"rang", "9002"}, // right-pointing angle bracket = ket,U+232A ISOtech -->

//

//

{"loz", "9674"}, // lozenge, U+25CA ISOpub -->

//

{"spades", "9824"}, // black spade suit, U+2660 ISOpub -->

//

{"clubs", "9827"}, // black club suit = shamrock,U+2663 ISOpub -->

{"hearts", "9829"}, // black heart suit = valentine,U+2665 ISOpub -->

{"diams", "9830"}, // black diamond suit, U+2666 ISOpub -->

//

{"OElig", "338"}, // -- latin capital ligature OE,U+0152 ISOlat2 -->

{"oelig", "339"}, // -- latin small ligature oe, U+0153 ISOlat2 -->

//

{"Scaron", "352"}, // -- latin capital letter S with caron,U+0160 ISOlat2 -->

{"scaron", "353"}, // -- latin small letter s with caron,U+0161 ISOlat2 -->

{"Yuml", "376"}, // -- latin capital letter Y with diaeresis,U+0178 ISOlat2 -->

//

{"circ", "710"}, // -- modifier letter circumflex accent,U+02C6 ISOpub -->

{"tilde", "732"}, // small tilde, U+02DC ISOdia -->

//

{"ensp", "8194"}, // en space, U+2002 ISOpub -->

{"emsp", "8195"}, // em space, U+2003 ISOpub -->

{"thinsp", "8201"}, // thin space, U+2009 ISOpub -->

{"zwnj", "8204"}, // zero width non-joiner,U+200C NEW RFC 2070 -->

{"zwj", "8205"}, // zero width joiner, U+200D NEW RFC 2070 -->

{"lrm", "8206"}, // left-to-right mark, U+200E NEW RFC 2070 -->

{"rlm", "8207"}, // right-to-left mark, U+200F NEW RFC 2070 -->

{"ndash", "8211"}, // en dash, U+2013 ISOpub -->

{"mdash", "8212"}, // em dash, U+2014 ISOpub -->

{"lsquo", "8216"}, // left single quotation mark,U+2018 ISOnum -->

{"rsquo", "8217"}, // right single quotation mark,U+2019 ISOnum -->

{"sbquo", "8218"}, // single low-9 quotation mark, U+201A NEW -->

{"ldquo", "8220"}, // left double quotation mark,U+201C ISOnum -->

{"rdquo", "8221"}, // right double quotation mark,U+201D ISOnum -->

{"bdquo", "8222"}, // double low-9 quotation mark, U+201E NEW -->

{"dagger", "8224"}, // dagger, U+2020 ISOpub -->

{"Dagger", "8225"}, // double dagger, U+2021 ISOpub -->

{"permil", "8240"}, // per mille sign, U+2030 ISOtech -->

{"lsaquo", "8249"}, // single left-pointing angle quotation mark,U+2039 ISO proposed -->

//

{"rsaquo", "8250"}, // single right-pointing angle quotation mark,U+203A ISO proposed -->

//

{"euro", "8364"}, // -- euro sign, U+20AC NEW -->

};

再扩展下

从前面可以看到转义字符中间的那段数字是unicode，那么 这个 转移字符可以 随便构造了 ，并不限于上面的定义，比如 中的unicode是20013，那么构造一个转移字符中,经过浏览器的渲染 就变回中了 ,虽然不必这么绕为了显示一个字符，但如果在一些不方便传输特殊字符的场景 就可以派上用途了相关阅读:

Win10 Mobile可实现文件系统的完全访问

PHP多线程编程之管道通信实例分析

android 开发教程之日历项目实践(一)

不到30行JS代码实现Excel表格的方法

C#托管堆对象实例包含内容分析

C++ 简单实现MFC ListControl 点击列头排序

js精准的倒计时函数分享

js 动态添加元素(div、li、img等)及设置属性的方法

Win8系统如何将常用应用固定在搜索框最顶端？将常用应用固定在搜索框最顶端的方法

浅谈javascript 函数内部属性

ubuntu虚拟机怎么设置全屏显示？

System.Timers.Timer定时执行程序示例代码

解决Asp.net Mvc返回JsonResult中DateTime类型数据格式问题的方法

html5开发之viewport使用