Html 解码的Java类

本类的主要作用，就是将那些HTML编码后的字符，转回本来对应的字符。尤其适合于一些特殊的符号。大部分以&开头

代码:

import java.util.HashMap;

public class HTMLDecoder {

public static final HashMap charTable;

public static String decode(String s) {
String t;
Character ch;
int tmpPos, i;

int maxPos = s.length();
StringBuffer sb = new StringBuffer(maxPos);
int curPos = 0;
while (curPos < maxPos) {
char c = s.charAt(curPos++);
if (c == '&') {
tmpPos = curPos;
if (tmpPos < maxPos) {
char d = s.charAt(tmpPos++);
if (d == '#') {
if (tmpPos < maxPos) {
d = s.charAt(tmpPos++);
if ((d == 'x') || (d == 'X')) {
if (tmpPos < maxPos) {
d = s.charAt(tmpPos++);
if (isHexDigit(d)) {
while (tmpPos < maxPos) {
d = s.charAt(tmpPos++);
if (!isHexDigit(d)) {
if (d == ';') {
t =
s.substring(
curPos + 2,
tmpPos - 1);
try {
i =
Integer.parseInt(
t,
16);
if ((i >= 0)
&& (i < 65536)) {
c = (char) i;
curPos = tmpPos;
}
} catch (NumberFormatException e) {
}
}
break;
}
}
}
}
} else if (isDigit(d)) {
while (tmpPos < maxPos) {
d = s.charAt(tmpPos++);
if (!isDigit(d)) {
if (d == ';') {
t =
s.substring(
curPos + 1,
tmpPos - 1);
try {
i = Integer.parseInt(t);
if ((i >= 0) && (i < 65536)) {
c = (char) i;
curPos = tmpPos;
}
} catch (NumberFormatException e) {
}
}
break;
}
}
}
}
} else if (isLetter(d)) {
while (tmpPos < maxPos) {
d = s.charAt(tmpPos++);
if (!isLetterOrDigit(d)) {
if (d == ';') {
t = s.substring(curPos, tmpPos - 1);
ch = (Character) charTable.get(t);
if (ch != null) {
c = ch.charValue();
curPos = tmpPos;
}
}
break;
}
}
}
}
}
sb.append(c);
}
return sb.toString();
}

private static boolean isLetterOrDigit(char c) {
return isLetter(c) || isDigit(c);
}

private static boolean isHexDigit(char c) {
return isHexLetter(c) || isDigit(c);
}

private static boolean isLetter(char c) {
return ((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z'));
}

private static boolean isHexLetter(char c) {
return ((c >= 'a') && (c <= 'f')) || ((c >= 'A') && (c <= 'F'));
}

private static boolean isDigit(char c) {
return (c >= '0') && (c <= '9');
}

public static String compact(String s) {
int maxPos = s.length();
StringBuffer sb = new StringBuffer(maxPos);
int curPos = 0;
while (curPos < maxPos) {
char c = s.charAt(curPos++);
if (isWhitespace(c)) {
while ((curPos < maxPos) && isWhitespace(s.charAt(curPos))) {
curPos++;
}
c = '/u0020';
}
sb.append(c);
}
return sb.toString();
}

// HTML is very particular about what constitutes white space.
public static boolean isWhitespace(char ch) {
return (ch == '/u0020')
|| (ch == '/r')
|| (ch == '/n')
|| (ch == '/u0009')
|| (ch == '/u000c')
|| (ch == '/u200b');
}

static {
charTable = new HashMap();
charTable.put("quot", new Character((char)34));
charTable.put("amp", new Character((char)38));
charTable.put("apos", new Character((char)39));
charTable.put("lt", new Character((char)60));
charTable.put("gt", new Character((char)62));
charTable.put("nbsp", new Character((char)160));
charTable.put("iexcl", new Character((char)161));
charTable.put("cent", new Character((char)162));
charTable.put("pound", new Character((char)163));
charTable.put("curren", new Character((char)164));
charTable.put("yen", new Character((char)165));
charTable.put("brvbar", new Character((char)166));
charTable.put("sect", new Character((char)167));
charTable.put("uml", new Character((char)168));
charTable.put("copy", new Character((char)169));
charTable.put("ordf", new Character((char)170));
charTable.put("laquo", new Character((char)171));
charTable.put("not", new Character((char)172));
charTable.put("shy", new Character((char)173));
charTable.put("reg", new Character((char)174));
charTable.put("macr", new Character((char)175));
charTable.put("deg", new Character((char)176));
charTable.put("plusmn", new Character((char)177));
charTable.put("sup2", new Character((char)178));
charTable.put("sup3", new Character((char)179));
charTable.put("acute", new Character((char)180));
charTable.put("micro", new Character((char)181));
charTable.put("para", new Character((char)182));
charTable.put("middot", new Character((char)183));
charTable.put("cedil", new Character((char)184));
charTable.put("sup1", new Character((char)185));
charTable.put("ordm", new Character((char)186));
charTable.put("raquo", new Character((char)187));
charTable.put("frac14", new Character((char)188));
charTable.put("frac12", new Character((char)189));
charTable.put("frac34", new Character((char)190));
charTable.put("iquest", new Character((char)191));
charTable.put("Agrave", new Character((char)192));
charTable.put("Aacute", new Character((char)193));
charTable.put("Acirc", new Character((char)194));
charTable.put("Atilde", new Character((char)195));
charTable.put("Auml", new Character((char)196));
charTable.put("Aring", new Character((char)197));
charTable.put("AElig", new Character((char)198));
charTable.put("Ccedil", new Character((char)199));
charTable.put("Egrave", new Character((char)200));
charTable.put("Eacute", new Character((char)201));
charTable.put("Ecirc", new Character((char)202));
charTable.put("Euml", new Character((char)203));
charTable.put("Igrave", new Character((char)204));
charTable.put("Iacute", new Character((char)205));
charTable.put("Icirc", new Character((char)206));
charTable.put("Iuml", new Character((char)207));
charTable.put("ETH", new Character((char)208));
charTable.put("Ntilde", new Character((char)209));
charTable.put("Ograve", new Character((char)210));
charTable.put("Oacute", new Character((char)211));
charTable.put("Ocirc", new Character((char)212));
charTable.put("Otilde", new Character((char)213));
charTable.put("Ouml", new Character((char)214));
charTable.put("times", new Character((char)215));
charTable.put("Oslash", new Character((char)216));
charTable.put("Ugrave", new Character((char)217));
charTable.put("Uacute", new Character((char)218));
charTable.put("Ucirc", new Character((char)219));
charTable.put("Uuml", new Character((char)220));
charTable.put("Yacute", new Character((char)221));
charTable.put("THORN", new Character((char)222));
charTable.put("szlig", new Character((char)223));
charTable.put("agrave", new Character((char)224));
charTable.put("aacute", new Character((char)225));
charTable.put("acirc", new Character((char)226));
charTable.put("atilde", new Character((char)227));
charTable.put("auml", new Character((char)228));
charTable.put("aring", new Character((char)229));
charTable.put("aelig", new Character((char)230));
charTable.put("ccedil", new Character((char)231));
charTable.put("egrave", new Character((char)232));
charTable.put("eacute", new Character((char)233));
charTable.put("ecirc", new Character((char)234));
charTable.put("euml", new Character((char)235));
charTable.put("igrave", new Character((char)236));
charTable.put("iacute", new Character((char)237));
charTable.put("icirc", new Character((char)238));
charTable.put("iuml", new Character((char)239));
charTable.put("eth", new Character((char)240));
charTable.put("ntilde", new Character((char)241));
charTable.put("ograve", new Character((char)242));
charTable.put("oacute", new Character((char)243));
charTable.put("ocirc", new Character((char)244));
charTable.put("otilde", new Character((char)245));
charTable.put("ouml", new Character((char)246));
charTable.put("divide", new Character((char)247));
charTable.put("oslash", new Character((char)248));
charTable.put("ugrave", new Character((char)249));
charTable.put("uacute", new Character((char)250));
charTable.put("ucirc", new Character((char)251));
charTable.put("uuml", new Character((char)252));
charTable.put("yacute", new Character((char)253));
charTable.put("thorn", new Character((char)254));
charTable.put("yuml", new Character((char)255));
charTable.put("OElig", new Character((char)338));
charTable.put("oelig", new Character((char)339));
charTable.put("Scaron", new Character((char)352));
charTable.put("scaron", new Character((char)353));
charTable.put("fnof", new Character((char)402));
charTable.put("circ", new Character((char)710));
charTable.put("tilde", new Character((char)732));
charTable.put("Alpha", new Character((char)913));
charTable.put("Beta", new Character((char)914));
charTable.put("Gamma", new Character((char)915));
charTable.put("Delta", new Character((char)916));
charTable.put("Epsilon", new Character((char)917));
charTable.put("Zeta", new Character((char)918));
charTable.put("Eta", new Character((char)919));
charTable.put("Theta", new Character((char)920));
charTable.put("Iota", new Character((char)921));
charTable.put("Kappa", new Character((char)922));
charTable.put("Lambda", new Character((char)923));
charTable.put("Mu", new Character((char)924));
charTable.put("Nu", new Character((char)925));
charTable.put("Xi", new Character((char)926));
charTable.put("Omicron", new Character((char)927));
charTable.put("i", new Character((char)928));
charTable.put("Rho", new Character((char)929));
charTable.put("Sigma", new Character((char)931));
charTable.put("Tau", new Character((char)932));
charTable.put("Upsilon", new Character((char)933));
charTable.put("hi", new Character((char)934));
charTable.put("Chi", new Character((char)935));
charTable.put("si", new Character((char)936));
charTable.put("Omega", new Character((char)937));
charTable.put("alpha", new Character((char)945));
charTable.put("beta", new Character((char)946));
charTable.put("gamma", new Character((char)947));
charTable.put("delta", new Character((char)948));
charTable.put("epsilon", new Character((char)949));
charTable.put("zeta", new Character((char)950));
charTable.put("eta", new Character((char)951));
charTable.put("theta", new Character((char)952));
charTable.put("iota", new Character((char)953));
charTable.put("kappa", new Character((char)954));
charTable.put("lambda", new Character((char)955));
charTable.put("mu", new Character((char)956));
charTable.put("nu", new Character((char)957));
charTable.put("xi", new Character((char)958));
charTable.put("omicron", new Character((char)959));
charTable.put("pi", new Character((char)960));
charTable.put("rho", new Character((char)961));
charTable.put("sigmaf", new Character((char)962));
charTable.put("sigma", new Character((char)963));
charTable.put("tau", new Character((char)964));
charTable.put("upsilon", new Character((char)965));
charTable.put("phi", new Character((char)966));
charTable.put("chi", new Character((char)967));
charTable.put("psi", new Character((char)968));
charTable.put("omega", new Character((char)969));
charTable.put("thetasym", new Character((char)977));
charTable.put("upsih", new Character((char)978));
charTable.put("piv", new Character((char)982));
charTable.put("ensp", new Character((char)8194));
charTable.put("emsp", new Character((char)8195));
charTable.put("thinsp", new Character((char)8201));
charTable.put("zwnj", new Character((char)8204));
charTable.put("zwj", new Character((char)8205));
charTable.put("lrm", new Character((char)8206));
charTable.put("rlm", new Character((char)8207));
charTable.put("ndash", new Character((char)8211));
charTable.put("mdash", new Character((char)8212));
charTable.put("lsquo", new Character((char)8216));
charTable.put("rsquo", new Character((char)8217));
charTable.put("sbquo", new Character((char)8218));
charTable.put("ldquo", new Character((char)8220));
charTable.put("rdquo", new Character((char)8221));
charTable.put("bdquo", new Character((char)8222));
charTable.put("dagger", new Character((char)8224));
charTable.put("Dagger", new Character((char)8225));
charTable.put("bull", new Character((char)8226));
charTable.put("hellip", new Character((char)8230));
charTable.put("permil", new Character((char)8240));
charTable.put("prime", new Character((char)8242));
charTable.put("rime", new Character((char)8243));
charTable.put("lsaquo", new Character((char)8249));
charTable.put("rsaquo", new Character((char)8250));
charTable.put("oline", new Character((char)8254));
charTable.put("frasl", new Character((char)8260));
charTable.put("euro", new Character((char)8364));
charTable.put("image", new Character((char)8465));
charTable.put("weierp", new Character((char)8472));
charTable.put("real", new Character((char)8476));
charTable.put("trade", new Character((char)8482));
charTable.put("alefsym", new Character((char)8501));
charTable.put("larr", new Character((char)8592));
charTable.put("uarr", new Character((char)8593));
charTable.put("rarr", new Character((char)8594));
charTable.put("darr", new Character((char)8595));
charTable.put("harr", new Character((char)8596));
charTable.put("crarr", new Character((char)8629));
charTable.put("lArr", new Character((char)8656));
charTable.put("uArr", new Character((char)8657));
charTable.put("rArr", new Character((char)8658));
charTable.put("dArr", new Character((char)8659));
charTable.put("hArr", new Character((char)8660));
charTable.put("forall", new Character((char)8704));
charTable.put("part", new Character((char)8706));
charTable.put("exist", new Character((char)8707));
charTable.put("empty", new Character((char)8709));
charTable.put("nabla", new Character((char)8711));
charTable.put("isin", new Character((char)8712));
charTable.put("notin", new Character((char)8713));
charTable.put("ni", new Character((char)8715));
charTable.put("prod", new Character((char)8719));
charTable.put("sum", new Character((char)8721));
charTable.put("minus", new Character((char)8722));
charTable.put("lowast", new Character((char)8727));
charTable.put("radic", new Character((char)8730));
charTable.put("prop", new Character((char)8733));
charTable.put("infin", new Character((char)8734));
charTable.put("ang", new Character((char)8736));
charTable.put("and", new Character((char)8743));
charTable.put("or", new Character((char)8744));
charTable.put("cap", new Character((char)8745));
charTable.put("cup", new Character((char)8746));
charTable.put("int", new Character((char)8747));
charTable.put("there4", new Character((char)8756));
charTable.put("sim", new Character((char)8764));
charTable.put("cong", new Character((char)8773));
charTable.put("asymp", new Character((char)8776));
charTable.put("ne", new Character((char)8800));
charTable.put("equiv", new Character((char)8801));
charTable.put("le", new Character((char)8804));
charTable.put("ge", new Character((char)8805));
charTable.put("sub", new Character((char)8834));
charTable.put("sup", new Character((char)8835));
charTable.put("nsub", new Character((char)8836));
charTable.put("sube", new Character((char)8838));
charTable.put("supe", new Character((char)8839));
charTable.put("oplus", new Character((char)8853));
charTable.put("otimes", new Character((char)8855));
charTable.put("perp", new Character((char)8869));
charTable.put("sdot", new Character((char)8901));
charTable.put("lceil", new Character((char)8968));
charTable.put("rceil", new Character((char)8969));
charTable.put("lfloor", new Character((char)8970));
charTable.put("rfloor", new Character((char)8971));
charTable.put("lang", new Character((char)9001));
charTable.put("rang", new Character((char)9002));
charTable.put("loz", new Character((char)9674));
charTable.put("spades", new Character((char)9824));
charTable.put("clubs", new Character((char)9827));
charTable.put("hearts", new Character((char)9829));
charTable.put("diams", new Character((char)9830));
}
}

相关问题:http://topic.csdn.net/u/20080130/01/8402ba64-d71b-4bac-b5be-81fc2958ba78.html