I have a string of the following format:
String name = "A|DescA+B|DescB+C|DescC+...X|DescX+"
So the repeating pattern is ?|?+, and I don't know how many there will be. The part I want to extract is the part before |...so for my example I want to extract a list (an ArrayList for example) that will contain:
[A, B, C, ... X]
I have tried the following pattern:
(.+)\\|.*\\+
but that doesn't work the way I want it to? Any suggestions?
To convert this into a list you can do like this:
String name = "A|DescA+B|DescB+C|DescC+X|DescX+";
Matcher m = Pattern.compile("([^|]+)\\|.*?\\+").matcher(name);
List<String> matches = new ArrayList<String>();
while (m.find()) {
matches.add(m.group(1));
}
This gives you the list:
[A, B, C, X]
Note the ? in the middle, that prevents the second part of the regex to consume the entire string, since it makes the * lazy instead of greedy.
You are consuming any character (.) and that includes the | so, the parser goes on munching everything, and once it's done taking any char, it looks for |, but there's nothing left.
So, try to match any character but | like this:
"([^|]+)\\|.*\\+"
And if it fits, make sure your all-but-| is at the beginning of the string using ^ and that there's a + at the end of the string with $:
"^([^|]+)\\|.*\\+$"
UPDATE: Tim Pietzcker makes a good point: since you are already matching until you find a |, you could just as well match the rest of the string and be done with it:
"^([^|]+).*\\+$"
UPDATE2: By the way, if you want to simply get the first part of the string, you can simplify things with:
myString.split("\\|")[0]
\\| (if there is at least one | in the string).Another idea: Find all characters between + (or start of string) and |:
List<String> matchList = new ArrayList<String>();
Pattern regex = Pattern.compile("(?<=^|[+])[^|]+");
Matcher regexMatcher = regex.matcher(subjectString);
while (regexMatcher.find()) {
matchList.add(regexMatcher.group());
}
I think the easiest solution would be to split by \\+, then for each part apply the (.+?)\\|.* pattern to extract the group you need.
