/**
* This function returns the begin offset of the input string where the first matched pattern is
* found.
*
* @param pattern pattern string to match
* @param input input string
* @return returns the offset of the beginning of the first matched pattern. if the match not
* found, it returns -1.
* @exception throws a FrameworkException when either pattern/input is null.
*/
public static int getBeginOffset(String pattern, String input) throws FrameworkException {
if (input == null || pattern == null) {
throw new FrameworkException(
"RegexUtils: getBeginOffset(): input or pattern is null."
+ "input = "
+ input
+ ", "
+ "pattern = "
+ pattern);
}
Perl5Util util = new Perl5Util();
int beginOffset = -1;
String formatPattern = null;
formatPattern = makePerl5MatchPattern(pattern);
if (util.match(formatPattern, input)) {
beginOffset = util.beginOffset(0);
} else {
Debug.log(Debug.MSG_STATUS, "RegexUtils: getBeginOffset(): No match found.");
}
return beginOffset;
}
/**
* 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 replaceFirst(String pattern, String input, String replacement)
throws FrameworkException {
if ((pattern == null) || (input == null) || (replacement == null)) {
throw new FrameworkException(
"RegexUtil: replaceFirst(): pattern or input cannot be null. "
+ "pattern = "
+ pattern
+ "input = "
+ input
+ "replacement = "
+ replacement);
}
String result = null;
String perl5SubstitutionPattern = null;
Perl5Util util = new Perl5Util();
// default return value
result = input;
perl5SubstitutionPattern = makePerl5SubstitutionPattern(pattern, replacement);
pattern = makePerl5MatchPattern(pattern);
if (util.match(pattern, input)) {
result = util.substitute(perl5SubstitutionPattern, input);
}
return result;
}
/**
* 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 - ", & original input - I didn't &0 to say
* "GOO".
*
* <p>After the first substitution with " and ": processed input - I didn't &0 to say
* "GOO".
*
* <p>When we do the second substitution with '&', we do not want to perform the pattern matching
* on the '&' of """ 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 & with non-negative look-ahead: processed input
* - I didn't &0 to say &quotGOO&quot.
*
* <p>After the second substitution with & and & with negative look-ahead: processed input - I
* didn't &0 to say "GOO".
*
* @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;
}
/**
* This function returns the matched string in input when the pattern is found.
*
* @param pattern pattern string to match
* @param input input string
* @return returns the portion of the matched string in the input
* @exception throws a FrameworkException when either pattern/input is null.
*/
public static String getMatch(String pattern, String input) throws FrameworkException {
if (input == null || pattern == null) {
throw new FrameworkException(
"RegexUtils: getMatch(): input or pattern is null."
+ "input ="
+ input
+ ", "
+ "pattern = "
+ pattern);
}
Perl5Util util = new Perl5Util();
boolean isMatched = false;
MatchResult matchResult = null;
// default return value is the original input
String result = input;
pattern = makePerl5MatchPattern(pattern);
if (util.match(pattern, input)) {
matchResult = util.getMatch();
result = matchResult.toString();
}
return result;
}
/**
* 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 - ", &
*
* @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();
}
/**
* 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();
}
/**
* This function checks in the input if there is other tokens in the begingTokens array than
* begin. This utility function is used on a string which is between a valid begin token and all
* possible other begin tokens. If there is another begin token of different kind is found, the
* substitution shouldn't occur. Consider this situation:
*
* <p>i.e.) <beginToken_0> "some string <beginToken_1> here to do the substitution on"
* <endToken_0> <beginToken_0> "another some string" <endToken_1>
*
* <p>In this case, the replaceAll() function finds the matched pair <beginToken_0> and
* <endToken_0> and attempt to perform the substitution. However, since there is another boundary
* _1 is overlapped with _0 boundary, we do not want to perform a string substitution.
*
* @param replacement replacement string to replace with
* @param beginToken begin boundary token
* @param endToken end boundary token
* @return true if any of other beginTokens in the beginToken[] than begin is found in the input
* string, false otherwise
*/
private static final boolean isOtherBeginTokenThere(
String begin, String input, String beginTokens[]) throws FrameworkException {
Perl5Util util = new Perl5Util();
for (int i = 0; i < beginTokens.length; i++) {
// look for the other token
if (!beginTokens[i].equals(begin)) {
String perl5Pattern = makePerl5MatchPattern(beginTokens[i]);
// if the input contains at least one beginToken which differs from the begin
if (util.match(perl5Pattern, input)) {
Debug.log(
Debug.MSG_STATUS, "RegexUtils: isOtherBeginTokenThere: token = " + perl5Pattern);
return true;
}
}
}
return false;
}
/**
* This function returns boolean value true when the pattern is found in the input string. Returns
* false otherwise.
*
* @param pattern pattern string to match
* @param input input string
* @return returns true if a match is found in the input string passed in, false otherwise.
* @exception throws a FrameworkException when either pattern/input is null.
*/
public static boolean match(String pattern, String input) throws FrameworkException {
if (input == null || pattern == null) {
throw new FrameworkException(
"RegexUtils: match(): input or pattern is null."
+ "input ="
+ input
+ ", "
+ "pattern = "
+ pattern);
}
Perl5Util util = new Perl5Util();
boolean isMatched = false;
// convert the pattern to the perl5 format
pattern = makePerl5MatchPattern(pattern);
isMatched = util.match(pattern, input);
return isMatched;
}
/**
* 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;
}
/**
* This function locates the first match on the begin token and replace all the pattern with the
* replacement the area after the begin token is located.
*
* @param pattern pattern string to match
* @param input input string
* @param replacement replacement string
* @param beginToken begin token string
* @return processed string. If there's no match on the begin token, it returns the original input
* by default.
* @exception throws a FrameworkException when the input/pattern/replacement is null.
*/
public static String replaceAllWithBeginToken(
String pattern, String input, String replacement, String beginToken)
throws FrameworkException {
if (input == null || pattern == null || replacement == null) {
throw new FrameworkException(
"RegexUtils: replaceAllWithBeginToken: input or pattern or replacement is null."
+ "\ninput = "
+ input
+ "\npattern = "
+ pattern
+ "\nreplacement = "
+ replacement);
}
Perl5Util util = new Perl5Util();
// default return value
String result = input;
// conversion to the valid perl5 pattern regex
String formatPattern = makePerl5MatchPattern(pattern);
// if the beginToken is null, just do the regular replaceAll
if (beginToken == null) {
result = replaceAll(formatPattern, input, replacement);
}
// find if there is begin token in the input string
else if (util.match(beginToken, input)) {
// pre has the string before the match and the mathced pattern
String pre = input.substring(0, util.endOffset(0));
// get the rest of the string after the begin token is found
input = input.substring(util.endOffset(0));
result = replaceAll(pattern, input, replacement);
result = pre + result;
}
return result;
}
/**
* This function checks if the replacement includes pattern string.
*
* <p>i.e 1) if ( pattern = &, replacement = & ) returns true i.e 2) if ( pattern = ",
* replacement = " ) returns false
*
* @param pattern - pattern string
* @param replacement - replacement string
* @return returns true if pattern string is a part of the replacement string, false, otherwise.
* @exception throws a FrameworkException when the pattern/replacement is null.
*/
public static boolean checkReplacement(String pattern, String replacement)
throws FrameworkException {
if (pattern == null || replacement == null) {
throw new FrameworkException(
"RegexUtils: checkReplacement: pattern or replacement is null."
+ "\npattern = "
+ pattern
+ "\nreplacement = "
+ replacement);
}
boolean check = false;
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)) {
check = true;
}
}
return check;
}
/**
* This function substitues ALL the occurence of the pattern in the input with the replacement
* passed in. The substitution is done only in the range bound by the begin token and the end
* token.
*
* @param pattern pattern string to match
* @param input input string
* @param replacement replacement string to replace with
* @param beginToken begin boundary token
* @param endToken end boundary token
* @param beginTokens[] an array of beginTokens - this is used for negative look ahead where there
* are other begin tokens to be recognized.
* @return returns processed string if both beginToken and the endToken are successfully found,
* returns the unproessed original input otherwise.
* @exception throws a FrameworkException when either pattern/input/replacement is null.
*/
public static String replaceAll(
String pattern,
String input,
String replacement,
String beginToken,
String endToken,
String beginTokens[])
throws FrameworkException {
if ((pattern == null) || (replacement == null) || (input == null)) {
Debug.log(
Debug.ALL_ERRORS,
"RegexUtils: replaceAll(): pattern or replacement or input is null. "
+ "\npattern = "
+ pattern
+ "\ninput = "
+ input
+ "\nreplacement = "
+ replacement);
throw new FrameworkException(
"RegexUtils: replaceAll(): pattern or replacement or input is null.");
}
Perl5Util util = new Perl5Util();
StringBuffer resultBuffer = new StringBuffer();
if ((beginToken == null) || (endToken == null)) {
// either beginToken or endToken cannot be null, however both can be null.
throw new FrameworkException(
"RegexUtils: replaceAll(): Either begin or end token is null. BeginToken = "
+ beginToken
+ ", "
+ "endToken = "
+ endToken);
} else // do pattern match
{
// making the Perl5 regular expression format pattern
String begin = makePerl5MatchPattern(beginToken);
String end = makePerl5MatchPattern(endToken);
boolean beginTokenMatch = true;
// if begin token found
while (beginTokenMatch) {
// check the input for each iteration. when there is no input, break out of the loop.
if (input == null) break;
beginTokenMatch = util.match(begin, input);
if (beginTokenMatch) {
String negativeLookAheadPattern =
makePerl5MatchPatternNegativeLookAhead(pattern, replacement);
int beginOffsetForBeginToken = util.beginOffset(0);
int endOffsetForBeginToken = util.endOffset(0);
// the input after the begin token
String subInput = input.substring(endOffsetForBeginToken);
// if end token passed in was an empty string
if (endToken.equals("")) {
String result = null;
try {
result = replaceAllWithBeginToken(pattern, input, replacement, beginToken);
} catch (FrameworkException e) {
Debug.log(Debug.ALL_ERRORS, "RegexUtils: replaceAll() failed." + e.getMessage());
}
return result;
} else if (util.match(end, subInput)) // endToken found
{
// begin offset for the end token relative to the input not subInput
int beginOffsetForEndToken = endOffsetForBeginToken + util.beginOffset(0);
int endOffsetForEndToken = endOffsetForBeginToken + util.endOffset(0);
// pre is the string before the beginToken and the beginToken
String pre = input.substring(0, endOffsetForBeginToken);
resultBuffer.append(pre);
// current is the string between the beginToken and the endToken
String current = input.substring(endOffsetForBeginToken, beginOffsetForEndToken);
// theRest is the rest of the input string after the endToken
String theRest = input.substring(endOffsetForEndToken);
// current is the string between begin token and the endtoken
current = skipOrphanedBeginToken(begin, current, resultBuffer);
if (isOtherBeginTokenThere(beginToken, current, beginTokens) == false) {
current = replaceAll(pattern, current, replacement);
} // isOtherBeginTokenThere
resultBuffer.append(current);
resultBuffer.append(input.substring(beginOffsetForEndToken, endOffsetForEndToken));
input = theRest;
} else // endToken not found
{
resultBuffer.append(input);
break;
}
} // if beginToken found
else // beginToken not found
{
resultBuffer.append(input);
break;
}
} // while begin token found
} // else do pattern match
return resultBuffer.toString();
}