Beispiel #1
0
  /**
   * This function composes the perl regular expression to perform pattern matching with negative
   * look ahead. This becomes handy when a replacement string includes some string that is also a
   * pattern. i.e.) pattern - ", & replacement - &quot, &amp original input - I didn't &0 to say
   * "GOO".
   *
   * <p>After the first substitution with " and &quot: processed input - I didn't &0 to say
   * &quotGOO&quot.
   *
   * <p>When we do the second substitution with '&', we do not want to perform the pattern matching
   * on the '&' of "&quot" since it is already a replacement. If we give the pattern like this with
   * perl's negative look-ahead functionality:
   *
   * <p>not-negative look-ahead pattern - & negative look-ahead pattern - &(?!quot)
   *
   * <p>After the second substitution with & and &amp with non-negative look-ahead: processed input
   * - I didn't &amp0 to say &ampquotGOO&ampquot.
   *
   * <p>After the second substitution with & and &amp with negative look-ahead: processed input - I
   * didn't &amp0 to say &quotGOO&quot.
   *
   * @param pattern - pattern string to match
   * @param replacement - replacement
   * @return returns the format pattern for perl5 negative look-ahead
   * @exception throws a FrameworkException when the input/pattern/replacement is null.
   */
  private static String makePerl5MatchPatternNegativeLookAhead(String pattern, String replacement)
      throws FrameworkException {
    if (pattern == null || replacement == null) {
      throw new FrameworkException(
          "RegexUtils: makePerl5MatchPatternNegativeLookAhead: pattern or replacement is null."
              + "\npattern = "
              + pattern
              + "\nreplacement = "
              + replacement);
    }

    String result = pattern;
    StringBuffer patternBuffer = new StringBuffer();

    Perl5Util util = new Perl5Util();
    String formatPattern = makePerl5MatchPattern(pattern);

    // check if the pattern string is a part of the replacement string
    if (util.match(formatPattern, replacement)) {
      if (replacement.startsWith(pattern)) {
        result = util.postMatch();
        patternBuffer.append(pattern);
        patternBuffer.append("(?!");
        patternBuffer.append(result);
        patternBuffer.append(")");
        result = patternBuffer.toString();
      } else {
        throw new FrameworkException(
            "ERROR: RegexUtils: makePerl5MatchPatternNegativeLookAhead: The pattern in the "
                + "replacement string should be at the beginning.");
      }
    }

    return result;
  }
Beispiel #2
0
  /**
   * This function composes the perl regular expression to perform pattern matching with negative
   * look ahead. This becomes handy when a replacement string includes some string that is also a
   * pattern.
   *
   * <p>i.e.) pattern - & replacement - &quot, &amp
   *
   * @param pattern - pattern string to match
   * @param replacements - an array of replacement strings
   * @return returns the format pattern for perl5 negative look-ahead
   * @exception throws a FrameworkException when the pattern/replacement is null.
   */
  private static String makePerl5MatchPatternNegativeLookAhead(
      String pattern, String replacements[]) throws FrameworkException {
    if (pattern == null || replacements.length < 0) {
      throw new FrameworkException(
          "RegexUtils: makePerl5MatchPatternNegativeLookAhead: pattern or replacement is null."
              + "\npattern = "
              + pattern
              + "\nreplacements.length = "
              + replacements.length);
    }

    String result = null;
    StringBuffer patternBuffer = new StringBuffer();

    Perl5Util util = new Perl5Util();
    String formatPattern = makePerl5MatchPattern(pattern);

    for (int i = 0; i < replacements.length; i++) {
      if (util.match(formatPattern, replacements[i])) {
        if (replacements[i].startsWith(pattern)) {
          result = util.postMatch();

          // very first one
          if (i == 0) {
            patternBuffer.append(pattern);
            patternBuffer.append("(?!");
          }
          patternBuffer.append(result);

          // the last one
          if (i == (replacements.length - 1)) {
            patternBuffer.append(")");
          } else // not the last one, cat the perl5 separater
          {
            patternBuffer.append("|");
          }

        } else {
          throw new FrameworkException(
              "ERROR: RegexUtils: makePerl5MatchPatternNegativeLookAhead: The pattern in the "
                  + "replacement string should be at the beginning.");
        }
      } else // no match found meaning invalid use of this function
      {
        throw new FrameworkException(
            "ERROR: RegexUtils: makePerl5MatchPatternNegativeLookAhead: "
                + "Invalid use of the function.");
      }
    }

    if (Debug.isLevelEnabled(Debug.MSG_STATUS)) {
      Debug.log(
          Debug.MSG_STATUS,
          "RegexUtils: makePerl5MatchPatternNegativeLookAhead: patternBuffer.toString() = "
              + patternBuffer.toString());
    }

    return patternBuffer.toString();
  }
Beispiel #3
0
  /**
   * This function replace only the first pattern matched with the replacement.
   *
   * @param pattern pattern string to match
   * @param input input string
   * @param replacement replacement string
   * @return returns the processed string
   * @exception throws a FrameworkException when the pattern/replacement is null.
   */
  public static String replaceLast(String pattern, String input, String replacement)
      throws FrameworkException {
    if ((pattern == null) || (input == null) || (replacement == null)) {
      throw new FrameworkException(
          "RegexUtil: replaceLast(): pattern or input cannot be null. "
              + "pattern = "
              + pattern
              + "input = "
              + input
              + "replacement = "
              + replacement);
    }

    Perl5Util util = new Perl5Util();
    MatchResult matchResult = null;
    String result = null;
    String pre = null;
    String post = null;
    StringBuffer resultBuffer = new StringBuffer();

    int length = input.length();

    String regex = makePerl5SubstitutionPattern(pattern, replacement);
    pattern = makePerl5MatchPattern(pattern);

    // counts the number of match and grab the last one
    while (util.match(pattern, input)) {
      // getting the string before match
      pre = util.preMatch();
      resultBuffer.append(pre);

      // get the matched string
      matchResult = util.getMatch();
      resultBuffer.append(matchResult.toString());

      // get the post string after the match
      post = util.postMatch();

      // the post becomes the new input
      input = post;
    }

    // get the last match found
    matchResult = util.getMatch();

    // do the string replacement on the pattern found
    result = util.substitute(regex, matchResult.toString());

    resultBuffer.append(result);
    resultBuffer.append(post);

    return resultBuffer.toString();
  }
Beispiel #4
0
  /**
   * The function checks and handles the situation where another begin token is found in between the
   * first begin token and the first end token. Such first beginToken is ignored. The current input
   * to be passed in to the replacement function will be the string between the LAST begin token and
   * the FIRST end token found.
   *
   * @param beginToken the pattern to look for
   * @param current input string
   * @param resultBuffer the buffer to hold the result
   * @return returns a Vector containing the substrings of the input that occur
   */
  private static final String skipOrphanedBeginToken(
      String beginToken, String current, StringBuffer resultBuffer) {
    Perl5Util util = new Perl5Util();
    boolean nextBeginTokenMatch = true;
    MatchResult matchResult = null;
    String remainderStr = null;
    String subCurrent = null;
    StringBuffer currentBuffer = new StringBuffer();
    String pre = null;

    // subCurrent is copy of the current to check if there is any next beginTokens
    subCurrent = current;

    while (nextBeginTokenMatch) {
      nextBeginTokenMatch = util.match(beginToken, subCurrent);

      if (nextBeginTokenMatch == true) {
        // pre is the string before the beginToken
        pre = util.preMatch();
        currentBuffer.append(pre);

        // get the  matched beginToken
        matchResult = util.getMatch();
        currentBuffer.append(matchResult.toString());

        // get the remaining string after the beginToken
        remainderStr = util.postMatch();
        subCurrent = remainderStr;
      } else // there is no match
      {
        // appending the string before the last begin token to the result
        resultBuffer.append(currentBuffer.toString());

        // finally get the string to perform the substitution on
        current = subCurrent;
        break;
      }
    } // while

    return current;
  }