如何在Java中取消显示HTML字符实体？

基本上，我想解码一个给定的Html文档，并替换所有特殊字符，例如

，
，
，
，
，
，
，

在.NET中，我们可以使用
HttpUtility.HtmlDecode

Java中的等效函数是什么？
我使用了Apache Commons来实现这一点：

取消显示包含实体的字符串
转义到包含
实际Unicode字符
对应于逃逸。支持
HTML4.0实体

如果您想模拟php函数htmlspecialchars\u decode使用php函数get\u html\u translation\u table（）转储表，然后使用java代码，如

static Map<String,String> html_specialchars_table = new Hashtable<String,String>();
static {
        html_specialchars_table.put("&lt;","<");
        html_specialchars_table.put("&gt;",">");
        html_specialchars_table.put("&amp;","&");
}
static String htmlspecialchars_decode_ENT_NOQUOTES(String s){
        Enumeration en = html_specialchars_table.keys();
        while(en.hasMoreElements()){
                String key = en.nextElement();
                String val = html_specialchars_table.get(key);
                s = s.replaceAll(key, val);
        }
        return s;
}

静态映射html_specialchars_table=new Hashtable（）；
静止的{
html_specialchars_table.put（“，”）；
html_specialchars_table.put（“&；”、“&”）；
}
静态字符串htmlspecialchars_decode_ENT_NOQUOTES（字符串s）{
枚举en=html_specialchars_table.keys（）；
while（en.hasMoreElements（））{
String key=en.nextElement（）；
字符串val=html\u specialchars\u table.get（键）；
s=s.replaceAll（键，值）；
}
返回s；
}
考虑使用Java类。您可能需要添加一些项目（并非所有实体都在列表中）

凯文·哈坎森（Kevin Hakanson）建议的Apache Commons StringEscapeUtils对我来说并不是100%有效；像‘（左单引号）这样的几个实体以某种方式被翻译成了“222”。我也尝试了org.jsoup，但也遇到了同样的问题。
我在项目中尝试了Apache Commons StringEscapeUtils.unescapeHtml3（），但对其性能不满意。事实证明，它做了很多不必要的操作。首先，它为每个调用分配一个StringWriter，即使字符串中没有要取消scape的内容。我以不同的方式重写了代码，现在它运行得更快了。无论谁在谷歌找到这个，都欢迎使用它

下面的代码取消了所有HTML3符号和数字转义（相当于ApacheUneScapeThml3）。如果需要HTML4，您可以向地图添加更多条目

package com.example;

import java.io.StringWriter;
import java.util.HashMap;

public class StringUtils {

    public static final String unescapeHtml3(final String input) {
        StringWriter writer = null;
        int len = input.length();
        int i = 1;
        int st = 0;
        while (true) {
            // look for '&'
            while (i < len && input.charAt(i-1) != '&')
                i++;
            if (i >= len)
                break;

            // found '&', look for ';'
            int j = i;
            while (j < len && j < i + MAX_ESCAPE + 1 && input.charAt(j) != ';')
                j++;
            if (j == len || j < i + MIN_ESCAPE || j == i + MAX_ESCAPE + 1) {
                i++;
                continue;
            }

            // found escape 
            if (input.charAt(i) == '#') {
                // numeric escape
                int k = i + 1;
                int radix = 10;

                final char firstChar = input.charAt(k);
                if (firstChar == 'x' || firstChar == 'X') {
                    k++;
                    radix = 16;
                }

                try {
                    int entityValue = Integer.parseInt(input.substring(k, j), radix);

                    if (writer == null) 
                        writer = new StringWriter(input.length());
                    writer.append(input.substring(st, i - 1));

                    if (entityValue > 0xFFFF) {
                        final char[] chrs = Character.toChars(entityValue);
                        writer.write(chrs[0]);
                        writer.write(chrs[1]);
                    } else {
                        writer.write(entityValue);
                    }

                } catch (NumberFormatException ex) { 
                    i++;
                    continue;
                }
            }
            else {
                // named escape
                CharSequence value = lookupMap.get(input.substring(i, j));
                if (value == null) {
                    i++;
                    continue;
                }

                if (writer == null) 
                    writer = new StringWriter(input.length());
                writer.append(input.substring(st, i - 1));

                writer.append(value);
            }

            // skip escape
            st = j + 1;
            i = st;
        }

        if (writer != null) {
            writer.append(input.substring(st, len));
            return writer.toString();
        }
        return input;
    }

    private static final String[][] ESCAPES = {
        {"\"",     "quot"}, // " - double-quote
        {"&",      "amp"}, // & - ampersand
        {"<",      "lt"}, // < - less-than
        {">",      "gt"}, // > - greater-than

        // Mapping to escape ISO-8859-1 characters to their named HTML 3.x equivalents.
        {"\u00A0", "nbsp"}, // non-breaking space
        {"\u00A1", "iexcl"}, // inverted exclamation mark
        {"\u00A2", "cent"}, // cent sign
        {"\u00A3", "pound"}, // pound sign
        {"\u00A4", "curren"}, // currency sign
        {"\u00A5", "yen"}, // yen sign = yuan sign
        {"\u00A6", "brvbar"}, // broken bar = broken vertical bar
        {"\u00A7", "sect"}, // section sign
        {"\u00A8", "uml"}, // diaeresis = spacing diaeresis
        {"\u00A9", "copy"}, // © - copyright sign
        {"\u00AA", "ordf"}, // feminine ordinal indicator
        {"\u00AB", "laquo"}, // left-pointing double angle quotation mark = left pointing guillemet
        {"\u00AC", "not"}, // not sign
        {"\u00AD", "shy"}, // soft hyphen = discretionary hyphen
        {"\u00AE", "reg"}, // ® - registered trademark sign
        {"\u00AF", "macr"}, // macron = spacing macron = overline = APL overbar
        {"\u00B0", "deg"}, // degree sign
        {"\u00B1", "plusmn"}, // plus-minus sign = plus-or-minus sign
        {"\u00B2", "sup2"}, // superscript two = superscript digit two = squared
        {"\u00B3", "sup3"}, // superscript three = superscript digit three = cubed
        {"\u00B4", "acute"}, // acute accent = spacing acute
        {"\u00B5", "micro"}, // micro sign
        {"\u00B6", "para"}, // pilcrow sign = paragraph sign
        {"\u00B7", "middot"}, // middle dot = Georgian comma = Greek middle dot
        {"\u00B8", "cedil"}, // cedilla = spacing cedilla
        {"\u00B9", "sup1"}, // superscript one = superscript digit one
        {"\u00BA", "ordm"}, // masculine ordinal indicator
        {"\u00BB", "raquo"}, // right-pointing double angle quotation mark = right pointing guillemet
        {"\u00BC", "frac14"}, // vulgar fraction one quarter = fraction one quarter
        {"\u00BD", "frac12"}, // vulgar fraction one half = fraction one half
        {"\u00BE", "frac34"}, // vulgar fraction three quarters = fraction three quarters
        {"\u00BF", "iquest"}, // inverted question mark = turned question mark
        {"\u00C0", "Agrave"}, // А - uppercase A, grave accent
        {"\u00C1", "Aacute"}, // Б - uppercase A, acute accent
        {"\u00C2", "Acirc"}, // В - uppercase A, circumflex accent
        {"\u00C3", "Atilde"}, // Г - uppercase A, tilde
        {"\u00C4", "Auml"}, // Д - uppercase A, umlaut
        {"\u00C5", "Aring"}, // Е - uppercase A, ring
        {"\u00C6", "AElig"}, // Ж - uppercase AE
        {"\u00C7", "Ccedil"}, // З - uppercase C, cedilla
        {"\u00C8", "Egrave"}, // И - uppercase E, grave accent
        {"\u00C9", "Eacute"}, // Й - uppercase E, acute accent
        {"\u00CA", "Ecirc"}, // К - uppercase E, circumflex accent
        {"\u00CB", "Euml"}, // Л - uppercase E, umlaut
        {"\u00CC", "Igrave"}, // М - uppercase I, grave accent
        {"\u00CD", "Iacute"}, // Н - uppercase I, acute accent
        {"\u00CE", "Icirc"}, // О - uppercase I, circumflex accent
        {"\u00CF", "Iuml"}, // П - uppercase I, umlaut
        {"\u00D0", "ETH"}, // Р - uppercase Eth, Icelandic
        {"\u00D1", "Ntilde"}, // С - uppercase N, tilde
        {"\u00D2", "Ograve"}, // Т - uppercase O, grave accent
        {"\u00D3", "Oacute"}, // У - uppercase O, acute accent
        {"\u00D4", "Ocirc"}, // Ф - uppercase O, circumflex accent
        {"\u00D5", "Otilde"}, // Х - uppercase O, tilde
        {"\u00D6", "Ouml"}, // Ц - uppercase O, umlaut
        {"\u00D7", "times"}, // multiplication sign
        {"\u00D8", "Oslash"}, // Ш - uppercase O, slash
        {"\u00D9", "Ugrave"}, // Щ - uppercase U, grave accent
        {"\u00DA", "Uacute"}, // Ъ - uppercase U, acute accent
        {"\u00DB", "Ucirc"}, // Ы - uppercase U, circumflex accent
        {"\u00DC", "Uuml"}, // Ь - uppercase U, umlaut
        {"\u00DD", "Yacute"}, // Э - uppercase Y, acute accent
        {"\u00DE", "THORN"}, // Ю - uppercase THORN, Icelandic
        {"\u00DF", "szlig"}, // Я - lowercase sharps, German
        {"\u00E0", "agrave"}, // а - lowercase a, grave accent
        {"\u00E1", "aacute"}, // б - lowercase a, acute accent
        {"\u00E2", "acirc"}, // в - lowercase a, circumflex accent
        {"\u00E3", "atilde"}, // г - lowercase a, tilde
        {"\u00E4", "auml"}, // д - lowercase a, umlaut
        {"\u00E5", "aring"}, // е - lowercase a, ring
        {"\u00E6", "aelig"}, // ж - lowercase ae
        {"\u00E7", "ccedil"}, // з - lowercase c, cedilla
        {"\u00E8", "egrave"}, // и - lowercase e, grave accent
        {"\u00E9", "eacute"}, // й - lowercase e, acute accent
        {"\u00EA", "ecirc"}, // к - lowercase e, circumflex accent
        {"\u00EB", "euml"}, // л - lowercase e, umlaut
        {"\u00EC", "igrave"}, // м - lowercase i, grave accent
        {"\u00ED", "iacute"}, // н - lowercase i, acute accent
        {"\u00EE", "icirc"}, // о - lowercase i, circumflex accent
        {"\u00EF", "iuml"}, // п - lowercase i, umlaut
        {"\u00F0", "eth"}, // р - lowercase eth, Icelandic
        {"\u00F1", "ntilde"}, // с - lowercase n, tilde
        {"\u00F2", "ograve"}, // т - lowercase o, grave accent
        {"\u00F3", "oacute"}, // у - lowercase o, acute accent
        {"\u00F4", "ocirc"}, // ф - lowercase o, circumflex accent
        {"\u00F5", "otilde"}, // х - lowercase o, tilde
        {"\u00F6", "ouml"}, // ц - lowercase o, umlaut
        {"\u00F7", "divide"}, // division sign
        {"\u00F8", "oslash"}, // ш - lowercase o, slash
        {"\u00F9", "ugrave"}, // щ - lowercase u, grave accent
        {"\u00FA", "uacute"}, // ъ - lowercase u, acute accent
        {"\u00FB", "ucirc"}, // ы - lowercase u, circumflex accent
        {"\u00FC", "uuml"}, // ь - lowercase u, umlaut
        {"\u00FD", "yacute"}, // э - lowercase y, acute accent
        {"\u00FE", "thorn"}, // ю - lowercase thorn, Icelandic
        {"\u00FF", "yuml"}, // я - lowercase y, umlaut
    };

    private static final int MIN_ESCAPE = 2;
    private static final int MAX_ESCAPE = 6;

    private static final HashMap<String, CharSequence> lookupMap;
    static {
        lookupMap = new HashMap<String, CharSequence>();
        for (final CharSequence[] seq : ESCAPES) 
            lookupMap.put(seq[1].toString(), seq[0]);
    }

}

package.com.example；
导入java.io.StringWriter；
导入java.util.HashMap；
公共类StringUtils{
公共静态最终字符串unescapeThml3（最终字符串输入）{
StringWriter=null；
int len=input.length（）；
int i=1；
int st=0；
while（true）{
//寻找“&”
而（i=len）
打破
//找到“&”，查找“；”
int j=i；
而（j0xFFFF）{
final char[]chrs=Character.toChars（entityValue）；
writer.write（chrs[0]）；
writer.write（chrs[1]）；
}否则{
writer.write（entityValue）；
}
}catch（NumberFormatException ex）{
i++；
继续；
}
}
否则{
//命名逃逸
CharSequence值=lookupMap.get（输入子字符串（i，j））；
如果（值==null）{
i++；
继续；
}
if（writer==null）
writer=newstringwriter（input.length（））；
writer.append（input.substring（st，i-1））；
writer.append（值）；
}
//越狱
st=j+1；
i=st；
}
if（writer！=null）{
writer.append（input.substring（st，len））；
返回writer.toString（）；
}
返回输入；
}
私有静态最终字符串[][]转义={
{“\”，“quot}，//”-双引号
{“&”，“amp”}，//&-和
{“”“gt”}，//>-大于
//映射以将ISO-8859-1字符转义为其命名的HTML 3.x等效项。
{“\u00A0”，“nbsp”}，//不间断空格
{“\u00A1”，“iexcl”}，//倒惊叹号
{“\u00A2”，“cent”}，//分号
{“\u00A3”，“磅”}，//磅符号
{“\u00A4”，“curren”}，//货币符号
{“\u00A5”，“yen”}，//yen符号=元符号
{“\u00A6”，“brvbar”}，//断条=断条
{“\u00A7”，“sect”}，//节号
{“\u00A8”，“uml”}，//diaeresis=间距diaeresis
{“\u00A9”，“复制”}，//）-版权标志
{“\u00AA”，“ordf”}，//女性顺序指示符
{“\u00AB”，“laquo”}，//左指双角度引号=左指导轨
{“\u00AC”，“not”}，//不签名
{“\u00AD”，“shy”}，//软连字符=任意连字符
{“\u00AE”，“reg”}，//？注册商标标志
{“\u00AF”，“macr”}，//macron=间距macron=上划线=APL下划线
{“\u00B0”，“deg”}，//度符号
{“\u00B1”，“plusmn”}，//正负号=加号或分钟
final String unescapedText = HtmlEscape.unescapeHtml(escapedText); 

text = text.replace("&Ccedil;", "Ç");
text = text.replace("&ccedil;", "ç");
text = text.replace("&Aacute;", "Á");
text = text.replace("&Acirc;", "Â");
text = text.replace("&Atilde;", "Ã");
text = text.replace("&Eacute;", "É");
text = text.replace("&Ecirc;", "Ê");
text = text.replace("&Iacute;", "Í");
text = text.replace("&Ocirc;", "Ô");
text = text.replace("&Otilde;", "Õ");
text = text.replace("&Oacute;", "Ó");
text = text.replace("&Uacute;", "Ú");
text = text.replace("&aacute;", "á");
text = text.replace("&acirc;", "â");
text = text.replace("&atilde;", "ã");
text = text.replace("&eacute;", "é");
text = text.replace("&ecirc;", "ê");
text = text.replace("&iacute;", "í");
text = text.replace("&ocirc;", "ô");
text = text.replace("&otilde;", "õ");
text = text.replace("&oacute;", "ó");
text = text.replace("&uacute;", "ú");

// textValue: <p>This is a&nbsp;sample. \"Granny\" Smith &#8211;.<\/p>\r\n
// becomes this: This is a sample. "Granny" Smith –.
// with one line of code:
// Jsoup.parse(textValue).getText(); // for older versions of Jsoup
Jsoup.parse(textValue).text();

// Another possibility may be the static unescapeEntities method:
boolean strictMode = true;
String unescapedString = org.jsoup.parser.Parser.unescapeEntities(textValue, strictMode);

public static String unescapeHtml3( String str ) {
    try {
        HTMLDocument doc = new HTMLDocument();
        new HTMLEditorKit().read( new StringReader( "<html><body>" + str ), doc, 0 );
        return doc.getText( 1, doc.getLength() );
    } catch( Exception ex ) {
        return str;
    }
}

import org.apache.commons.lang.StringEscapeUtils;
...
String decodedXML= StringEscapeUtils.unescapeHtml(encodedXML);

import org.apache.commons.lang3.StringEscapeUtils;
...
String decodedXML= StringEscapeUtils.unescapeHtml4(encodedXML);

String cleanedString = StringEscapeUtils.unescapeHtml4(originalString);

cleanedString = cleanedString.trim();

import static org.springframework.web.util.HtmlUtils.htmlUnescape;

...

String result = htmlUnescape(source);