java正则表达式过滤html标签

import java.util.regex.Matcher;   import java.util.regex.Pattern;     /**   * <p>   * Title: HTML相关的正则表达式工具类   * </p>   * <p>   * Description: 包括过滤HTML标记，转换HTML标记，替换特定HTML标记   * </p>   * <p>   * Copyright: Copyright (c) 2006   * </p>   *    * @author hejian   * @version 1.0   * @createtime 2006-10-16   */    public class HtmlRegexpUtil {   private final static String regxpForHtml = "<([^>]*)>"; // 过滤所有以<开头以>结尾的标签     private final static String regxpForImgTag = "<\\s*img\\s+([^>]*)\\s*>"; // 找出IMG标签     private final static String regxpForImaTagSrcAttrib = "src=\"([^\"]+)\""; // 找出IMG标签的SRC属性     /**       *        */  public HtmlRegexpUtil() {   // TODO Auto-generated constructor stub       }     /**       *        * 基本功能：替换标记以正常显示       * <p>       *        * @param input       * @return String       */  public String replaceTag(String input) {   if (!hasSpecialChars(input)) {   return input;           }           StringBuffer filtered = new StringBuffer(input.length());   char c;   for (int i = 0; i <= input.length() - 1; i++) {               c = input.charAt(i);   switch (c) {   case '<':                   filtered.append("&lt;");   break;   case '>':                   filtered.append("&gt;");   break;   case '"':                   filtered.append("&quot;");   break;   case '&':                   filtered.append("&amp;");   break;   default:                   filtered.append(c);               }             }   return (filtered.toString());       }     /**       *        * 基本功能：判断标记是否存在       * <p>       *        * @param input       * @return boolean       */  public boolean hasSpecialChars(String input) {   boolean flag = false;   if ((input != null) && (input.length() > 0)) {   char c;   for (int i = 0; i <= input.length() - 1; i++) {                   c = input.charAt(i);   switch (c) {   case '>':                       flag = true;   break;   case '<':     <p style="color:transparent">本文来源gao!%daima.com搞$代*!码$网3</p>                  flag = true;   break;   case '"':                       flag = true;   break;   case '&':                       flag = true;   break;                   }               }           }   return flag;       }     /**       *        * 基本功能：过滤所有以"<"开头以">"结尾的标签       * <p>       *        * @param str       * @return String       */  public static String filterHtml(String str) {           Pattern pattern = Pattern.compile(regxpForHtml);           Matcher matcher = pattern.matcher(str);           StringBuffer sb = new StringBuffer();   boolean result1 = matcher.find();   while (result1) {               matcher.appendReplacement(sb, "");               result1 = matcher.find();           }           matcher.appendTail(sb);   return sb.toString();       }     /**       *        * 基本功能：过滤指定标签       * <p>       *        * @param str       * @param tag       *            指定标签       * @return String       */  public static String fiterHtmlTag(String str, String tag) {           String regxp = "<\\s*" + tag + "\\s+([^>]*)\\s*>";           Pattern pattern = Pattern.compile(regxp);           Matcher matcher = pattern.matcher(str);           StringBuffer sb = new StringBuffer();   boolean result1 = matcher.find();   while (result1) {               matcher.appendReplacement(sb, "");               result1 = matcher.find();           }           matcher.appendTail(sb);   return sb.toString();       }     /**       *        * 基本功能：替换指定的标签       * <p>       *        * @param str       * @param beforeTag       *            要替换的标签       * @param tagAttrib       *            要替换的标签属性值       * @param startTag       *            新标签开始标记       * @param endTag       *            新标签结束标记       * @return String       * @如：替换img标签的src属性值为[img]属性值[/img]       */  public static String replaceHtmlTag(String str, String beforeTag,               String tagAttrib, String startTag, String endTag) {           String regxpForTag = "<\\s*" + beforeTag + "\\s+([^>]*)\\s*>";           String regxpForTagAttrib = tagAttrib + "=\"([^\"]+)\"";           Pattern patternForTag = Pattern.compile(regxpForTag);           Pattern patternForAttrib = Pattern.compile(regxpForTagAttrib);           Matcher matcherForTag = patternForTag.matcher(str);           StringBuffer sb = new StringBuffer();   boolean result = matcherForTag.find();   while (result) {               StringBuffer sbreplace = new StringBuffer();               Matcher matcherForAttrib = patternForAttrib.matcher(matcherForTag                       .group(1));   if (matcherForAttrib.find()) {                   matcherForAttrib.appendReplacement(sbreplace, startTag   + matcherForAttrib.group(1) + endTag);               }               matcherForTag.appendReplacement(sb, sbreplace.toString());               result = matcherForTag.find();           }           matcherForTag.appendTail(sb);   return sb.toString();       }   }