import java.util.regex.Matcher; import java.util.regex.Pattern;  /**  * <p>  * Title: HTML相關的正則表達式工具類  * </p>  * <p>  * Description: 包括過濾HTML標記，轉換HTML標記，替換特定HTML標記  * </p>  * <p>  * Copyright: Copyright (c) 2006  * </p>  *  * @author hejian  * @version 1.0  * @createtime 2006-10-16  */  public class HtmlRegexpUtil {  private final static String regxpForHtml = "<([^>]*)>"; // 過濾所有以<開頭以>結尾的標簽   private final static String regxpForImgTag = "<//s*img//s+([^>]*)//s*>"; // 找出IMG標簽   private final static String regxpForImaTagSrcAttrib = "src=/"([^/"]+)/""; // 找出IMG標簽的SRC屬性   /**   *   */  public HtmlRegexpUtil() {   // TODO Auto-generated constructor stub  }   /**   *   * 基本功能：替換標記以正常顯示   * <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("<");     break;    case '>':     filtered.append(">");     break;    case '"':     filtered.append(""");     break;    case '&':     filtered.append("&");     break;    default:     filtered.append(c);    }    }   return (filtered.toString());  }   /**   *   * 基本功能：判斷標記是否存在   * <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 '<':      flag = true;      break;     case '"':      flag = true;      break;     case '&':      flag = true;      break;     }    }   }   return flag;  }   /**   *   * 基本功能：過濾所有以"<"開頭以">"結尾的標簽   * <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：過濾指定標簽   * <p>   *   * @param str   * @param tag   *   指定標簽   * @return String   */  public static String fiterHtmlTag(String str, String tag) {   String regxp = "<//s*" + tag + "http://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：替換指定的標簽   * <p>   *   * @param str   * @param beforeTag   *   要替換的標簽   * @param tagAttrib   *   要替換的標簽屬性值   * @param startTag   *   新標簽開始標記   * @param endTag   *   新標簽結束標記   * @return String   * @如：替換img標簽的src屬性值為[img]屬性值[/img]   */  public static String replaceHtmlTag(String str, String beforeTag,    String tagAttrib, String startTag, String endTag) {   String regxpForTag = "<//s*" + beforeTag + "http://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();  } }