Regular Expression and newline woes

Question

Hi,
I have the following string that I would like to parse with reg expressions.
String myString = "YAL017W\nYAL018C\nYAL019W\nYAL020C\nYAL001C\n"I am using the following to parse it.
([^\n]+)[\n]?I do not want to use the split method as I need to integrate this with another expression.
How can I make valueOkQ true?
Pattern myPattern = Pattern.compile("([^\n]+)[\n]?", Pattern.MULTILINE | Pattern.DOTALL | Pattern.UNIX_LINES);
Matcher myMatcher = myPattern.matcher(myString );
bollean valueOkQ = myMatcher.matches();Interestingly enough, when I have the following,
String myString = "YAL017W\n"the following seems to match fine.
([^\n]+)[\n]?What is wrong with the first case?
Edited by: VanJay011379 on Feb 1, 2008 1:21 AM

Answer 1

Your regex only matches one instance of (some non-linefeed characters, optionally followed by a linefeed). If you want it to match more than one, you have to wrap that regex in parentheses and add a quantifier: Pattern myPattern = Pattern.compile("(([^\n]+)\n?)+"); By the way, there's no need for any of the flags you used: MULTILINE, DOTALL and UNIX_LINES. They change the meanings of the '^', '$' and '.' metacharacters, but you aren't using any of them.
@paulcw, the Pattern compiler can accept either a linefeed character or the escape sequence \n to match a linefeed, so these two regexes match the same thing: Pattern p = Pattern.compile("\n");
Pattern p = Pattern.compile("\\n");