HtmlUtils.java
package org.spf4j.base;
//CHECKSTYLE:OFF
/*
* Copyright 2002-2004 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.HashMap;
import java.util.Map;
/**
* Utility class for HTML escaping. Escapes and unescapes based on the W3C HTML
* 4.01 recommendation.
*
* <p>Reference:
* <a href="http://www.w3.org/TR/html4/charset.html">
* http://www.w3.org/TR/html4/charset.html
* </a>
*
* @author Chris Wilson
* @author Juergen Hoeller
* @since 01.03.2003
*/
public final class HtmlUtils {
private HtmlUtils() {
}
private static final String EMPTY_REFERENCE = "&;";
private static final String REFERENCE_START = "&#";
private static final String MALFORMED_REFERENCE = "&#;";
private static final Map ENTITIES = new HashMap();
static {
ENTITIES.put("nbsp", 160);
ENTITIES.put("iexcl", 161);
ENTITIES.put("cent", 162);
ENTITIES.put("pound", 163);
ENTITIES.put("curren", 164);
ENTITIES.put("yen", 165);
ENTITIES.put("brvbar", 166);
ENTITIES.put("sect", 167);
ENTITIES.put("uml", 168);
ENTITIES.put("copy", 169);
ENTITIES.put("ordf", 170);
ENTITIES.put("laquo", 171);
ENTITIES.put("not", 172);
ENTITIES.put("shy", 173);
ENTITIES.put("reg", 174);
ENTITIES.put("macr", 175);
ENTITIES.put("deg", 176);
ENTITIES.put("plusmn", 177);
ENTITIES.put("sup2", 178);
ENTITIES.put("sup3", 179);
ENTITIES.put("acute", 180);
ENTITIES.put("micro", 181);
ENTITIES.put("para", 182);
ENTITIES.put("middot", 183);
ENTITIES.put("cedil", 184);
ENTITIES.put("sup1", 185);
ENTITIES.put("ordm", 186);
ENTITIES.put("raquo", 187);
ENTITIES.put("frac14", 188);
ENTITIES.put("frac12", 189);
ENTITIES.put("frac34", 190);
ENTITIES.put("iquest", 191);
ENTITIES.put("Agrave", 192);
ENTITIES.put("Aacute", 193);
ENTITIES.put("Acirc", 194);
ENTITIES.put("Atilde", 195);
ENTITIES.put("Auml", 196);
ENTITIES.put("Aring", 197);
ENTITIES.put("AElig", 198);
ENTITIES.put("Ccedil", 199);
ENTITIES.put("Egrave", 200);
ENTITIES.put("Eacute", 201);
ENTITIES.put("Ecirc", 202);
ENTITIES.put("Euml", 203);
ENTITIES.put("Igrave", 204);
ENTITIES.put("Iacute", 205);
ENTITIES.put("Icirc", 206);
ENTITIES.put("Iuml", 207);
ENTITIES.put("ETH", 208);
ENTITIES.put("Ntilde", 209);
ENTITIES.put("Ograve", 210);
ENTITIES.put("Oacute", 211);
ENTITIES.put("Ocirc", 212);
ENTITIES.put("Otilde", 213);
ENTITIES.put("Ouml", 214);
ENTITIES.put("times", 215);
ENTITIES.put("Oslash", 216);
ENTITIES.put("Ugrave", 217);
ENTITIES.put("Uacute", 218);
ENTITIES.put("Ucirc", 219);
ENTITIES.put("Uuml", 220);
ENTITIES.put("Yacute", 221);
ENTITIES.put("THORN", 222);
ENTITIES.put("szlig", 223);
ENTITIES.put("agrave", 224);
ENTITIES.put("aacute", 225);
ENTITIES.put("acirc", 226);
ENTITIES.put("atilde", 227);
ENTITIES.put("auml", 228);
ENTITIES.put("aring", 229);
ENTITIES.put("aelig", 230);
ENTITIES.put("ccedil", 231);
ENTITIES.put("egrave", 232);
ENTITIES.put("eacute", 233);
ENTITIES.put("ecirc", 234);
ENTITIES.put("euml", 235);
ENTITIES.put("igrave", 236);
ENTITIES.put("iacute", 237);
ENTITIES.put("icirc", 238);
ENTITIES.put("iuml", 239);
ENTITIES.put("eth", 240);
ENTITIES.put("ntilde", 241);
ENTITIES.put("ograve", 242);
ENTITIES.put("oacute", 243);
ENTITIES.put("ocirc", 244);
ENTITIES.put("otilde", 245);
ENTITIES.put("ouml", 246);
ENTITIES.put("divide", 247);
ENTITIES.put("oslash", 248);
ENTITIES.put("ugrave", 249);
ENTITIES.put("uacute", 250);
ENTITIES.put("ucirc", 251);
ENTITIES.put("uuml", 252);
ENTITIES.put("yacute", 253);
ENTITIES.put("thorn", 254);
ENTITIES.put("yuml", 255);
ENTITIES.put("fnof", 402);
ENTITIES.put("Alpha", 913);
ENTITIES.put("Beta", 914);
ENTITIES.put("Gamma", 915);
ENTITIES.put("Delta", 916);
ENTITIES.put("Epsilon", 917);
ENTITIES.put("Zeta", 918);
ENTITIES.put("Eta", 919);
ENTITIES.put("Theta", 920);
ENTITIES.put("Iota", 921);
ENTITIES.put("Kappa", 922);
ENTITIES.put("Lambda", 923);
ENTITIES.put("Mu", 924);
ENTITIES.put("Nu", 925);
ENTITIES.put("Xi", 926);
ENTITIES.put("Omicron", 927);
ENTITIES.put("Pi", 928);
ENTITIES.put("Rho", 929);
ENTITIES.put("Sigma", 931);
ENTITIES.put("Tau", 932);
ENTITIES.put("Upsilon", 933);
ENTITIES.put("Phi", 934);
ENTITIES.put("Chi", 935);
ENTITIES.put("Psi", 936);
ENTITIES.put("Omega", 937);
ENTITIES.put("alpha", 945);
ENTITIES.put("beta", 946);
ENTITIES.put("gamma", 947);
ENTITIES.put("delta", 948);
ENTITIES.put("epsilon", 949);
ENTITIES.put("zeta", 950);
ENTITIES.put("eta", 951);
ENTITIES.put("theta", 952);
ENTITIES.put("iota", 953);
ENTITIES.put("kappa", 954);
ENTITIES.put("lambda", 955);
ENTITIES.put("mu", 956);
ENTITIES.put("nu", 957);
ENTITIES.put("xi", 958);
ENTITIES.put("omicron", 959);
ENTITIES.put("pi", 960);
ENTITIES.put("rho", 961);
ENTITIES.put("sigmaf", 962);
ENTITIES.put("sigma", 963);
ENTITIES.put("tau", 964);
ENTITIES.put("upsilon", 965);
ENTITIES.put("phi", 966);
ENTITIES.put("chi", 967);
ENTITIES.put("psi", 968);
ENTITIES.put("omega", 969);
ENTITIES.put("thetasym", 977);
ENTITIES.put("upsih", 978);
ENTITIES.put("piv", 982);
ENTITIES.put("bull", 8226);
ENTITIES.put("hellip", 8230);
ENTITIES.put("prime", 8242);
ENTITIES.put("Prime", 8243);
ENTITIES.put("oline", 8254);
ENTITIES.put("frasl", 8260);
ENTITIES.put("weierp", 8472);
ENTITIES.put("image", 8465);
ENTITIES.put("real", 8476);
ENTITIES.put("trade", 8482);
ENTITIES.put("alefsym", 8501);
ENTITIES.put("larr", 8592);
ENTITIES.put("uarr", 8593);
ENTITIES.put("rarr", 8594);
ENTITIES.put("darr", 8595);
ENTITIES.put("harr", 8596);
ENTITIES.put("crarr", 8629);
ENTITIES.put("lArr", 8656);
ENTITIES.put("uArr", 8657);
ENTITIES.put("rArr", 8658);
ENTITIES.put("dArr", 8659);
ENTITIES.put("hArr", 8660);
ENTITIES.put("forall", 8704);
ENTITIES.put("part", 8706);
ENTITIES.put("exist", 8707);
ENTITIES.put("empty", 8709);
ENTITIES.put("nabla", 8711);
ENTITIES.put("isin", 8712);
ENTITIES.put("notin", 8713);
ENTITIES.put("ni", 8715);
ENTITIES.put("prod", 8719);
ENTITIES.put("sum", 8721);
ENTITIES.put("minus", 8722);
ENTITIES.put("lowast", 8727);
ENTITIES.put("radic", 8730);
ENTITIES.put("prop", 8733);
ENTITIES.put("infin", 8734);
ENTITIES.put("ang", 8736);
ENTITIES.put("and", 8743);
ENTITIES.put("or", 8744);
ENTITIES.put("cap", 8745);
ENTITIES.put("cup", 8746);
ENTITIES.put("int", 8747);
ENTITIES.put("there4", 8756);
ENTITIES.put("sim", 8764);
ENTITIES.put("cong", 8773);
ENTITIES.put("asymp", 8776);
ENTITIES.put("ne", 8800);
ENTITIES.put("equiv", 8801);
ENTITIES.put("le", 8804);
ENTITIES.put("ge", 8805);
ENTITIES.put("sub", 8834);
ENTITIES.put("sup", 8835);
ENTITIES.put("nsub", 8836);
ENTITIES.put("sube", 8838);
ENTITIES.put("supe", 8839);
ENTITIES.put("oplus", 8853);
ENTITIES.put("otimes", 8855);
ENTITIES.put("perp", 8869);
ENTITIES.put("sdot", 8901);
ENTITIES.put("lceil", 8968);
ENTITIES.put("rceil", 8969);
ENTITIES.put("lfloor", 8970);
ENTITIES.put("rfloor", 8971);
ENTITIES.put("lang", 9001);
ENTITIES.put("rang", 9002);
ENTITIES.put("loz", 9674);
ENTITIES.put("spades", 9824);
ENTITIES.put("clubs", 9827);
ENTITIES.put("hearts", 9829);
ENTITIES.put("diams", 9830);
ENTITIES.put("quot", 34);
ENTITIES.put("amp", 38);
ENTITIES.put("lt", 60);
ENTITIES.put("gt", 62);
ENTITIES.put("OElig", 338);
ENTITIES.put("oelig", 339);
ENTITIES.put("Scaron", 352);
ENTITIES.put("scaron", 353);
ENTITIES.put("Yuml", 376);
ENTITIES.put("circ", 710);
ENTITIES.put("tilde", 732);
ENTITIES.put("ensp", 8194);
ENTITIES.put("emsp", 8195);
ENTITIES.put("thinsp", 8201);
ENTITIES.put("zwnj", 8204);
ENTITIES.put("zwj", 8205);
ENTITIES.put("lrm", 8206);
ENTITIES.put("rlm", 8207);
ENTITIES.put("ndash", 8211);
ENTITIES.put("mdash", 8212);
ENTITIES.put("lsquo", 8216);
ENTITIES.put("rsquo", 8217);
ENTITIES.put("sbquo", 8218);
ENTITIES.put("ldquo", 8220);
ENTITIES.put("rdquo", 8221);
ENTITIES.put("bdquo", 8222);
ENTITIES.put("dagger", 8224);
ENTITIES.put("Dagger", 8225);
ENTITIES.put("permil", 8240);
ENTITIES.put("lsaquo", 8249);
ENTITIES.put("rsaquo", 8250);
ENTITIES.put("euro", 8364);
}
/**
* Turn special characters into HTML character references. Handles complete
* character set defined in HTML 4.01 recommendation.
* <p>Escapes all special characters to their corresponding numerial
* reference in the decimal format: &#<i>Decimal</i>;
* <p>Reference:
* <a href="http://www.w3.org/TR/html4/sgml/entities.html">
* http://www.w3.org/TR/html4/sgml/entities.html
* </a>
*/
public static String htmlEscape(String s) {
if (s == null) {
return null;
}
StringBuilder escaped = new StringBuilder(s.length());
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
// handle non special ASCII chars first since they will be most common
if ((c >= 0 && c <= 33)
|| (c >= 35 && c <= 37)
|| (c >= 39 && c <= 59)
|| (c == 61)
|| (c >= 63 && c <= 159)) {
escaped.append(c);
continue;
}
// handle special chars
if (c == 34) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 38) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 60) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 62) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 160 && c <= 255) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 338 && c <= 339) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 352 && c <= 353) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 376) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 402) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 710) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 732) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 913 && c <= 929) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 931 && c <= 937) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 945 && c <= 969) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 977 && c <= 978) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 982) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8194 && c <= 8195) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8201) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8204 && c <= 8207) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8211 && c <= 8212) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8216 && c <= 8218) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8220 && c <= 8222) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8224 && c <= 8226) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8230) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8240) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8242 && c <= 8243) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8249 && c <= 8250) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8254) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8260) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8364) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8465) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8472) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8476) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8482) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8501) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8592 && c <= 8596) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8629) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8656 && c <= 8660) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8704) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8706 && c <= 8707) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8709) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8711 && c <= 8713) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8715) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8719) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8721 && c <= 8722) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8727) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8730) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8733 && c <= 8734) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8736) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8743 && c <= 8747) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8756) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8764) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8773) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8776) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8800 && c <= 8801) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8804 && c <= 8805) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8834 && c <= 8836) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8838 && c <= 8839) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8853) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8855) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8869) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 8901) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 8968 && c <= 8971) {
writeDecimalReference(c, escaped);
continue;
}
if (c >= 9001 && c <= 9002) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 9674) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 9824) {
writeDecimalReference(c, escaped);
continue;
}
if (c == 9827) {
writeDecimalReference(c, escaped);
continue;
}
// all other chars
escaped.append(c);
}
return escaped.toString();
}
private static final int MAX_ESCAPE_SEQ = 12;
/**
* Turn HTML character references into their plain text UNICODE equivalent.
* <p>Handles complete character set defined in HTML 4.01 recommendation and
* all reference types (decimal, hex, and entity).
* <p>Correctly converts the following formats:
* <blockquote>
* &#<i>Decimal</i>; - <i>(Example: &#68;)</i><br>
* &#x<i>Hex</i>; - <i>(Example: &#xE5;) case insensitive</i><br>
* &#<i>Entity</i>; - <i>(Example: &amp;) case sensitive</i>
* </blockquote>
* Gracefully handles malformed character references by copying original
* characters as is when encountered.<p>
* <p>Reference:
* <a href="http://www.w3.org/TR/html4/sgml/entities.html">
* http://www.w3.org/TR/html4/sgml/entities.html
* </a>
*/
public static String htmlUnescape(final String s) {
if (s == null) {
return null;
}
StringBuilder unescaped = new StringBuilder(s.length());
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == '&') {
// don't look more than 12 chars ahead as reference like strings
// should not be longer than 12 chars in length (including ';')
// prevents the entire string from being searched when an '&'
// with no following ';' is an encountered
int start = Math.min(i + 1, s.length() - 1);
int end = Math.min(s.length(), start + MAX_ESCAPE_SEQ);
String reference = s.substring(start, end);
int semi = reference.indexOf(';');
if (semi == -1) {
unescaped.append(c);
continue;
}
reference = reference.substring(0, semi);
i = start + semi;
// try entity reference first
Integer iso = (Integer) ENTITIES.get(reference);
if (iso != null) {
unescaped.append((char) iso.intValue());
continue;
}
if (reference.length() == 0) {
unescaped.append(EMPTY_REFERENCE);
continue;
}
if (reference.charAt(0) == '#') {
if (reference.length() > 2) {
int index = 1;
if (reference.charAt(1) == 'x' || reference.charAt(1) == 'X') {
index = 2;
}
try {
unescaped.append(
(char) Integer.parseInt(
reference.substring(index),
(index == 1) ? 10 : 16));
continue;
} catch (NumberFormatException e) {
// wasn't hex or decimal, copy original chars
unescaped.append('&').append(reference).append(';');
continue;
}
}
unescaped.append(MALFORMED_REFERENCE);
continue;
}
// may not be valid reference, forget it
i = start - 1;
}
unescaped.append(c);
}
return unescaped.toString();
}
/**
* Write the given character as decimal reference.
*
* @param c the character to write
* @param buf the buffer to write into
*/
private static void writeDecimalReference(final char c, final StringBuilder buf) {
buf.append(REFERENCE_START);
buf.append((int) c);
buf.append(';');
}
}