Question

I have a text file that contains some strings separated by “,”. Strings are in the form of: “x:somestring:any string”. I’m interested in extracting “somestring” value only. I could extract “somestring:any string” by replacing the “x:” with “” using:

Pattern p= Pattern.compile("x:", Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher("");

But as I said before, I’m interested only in “somestring”. Is it possible to add a second pattern in order to replace “:any string” with “”. I thought of repeating the same process again, but I wanted to ask about a better way. Is there any way to improve my regular expression? Please note that “somestring” and “any string” are not fixed values.

Answer 1

If you have a string subjectString that contains "x:somestring:any string", then the following will extract somestring:

Pattern regex = Pattern.compile(
    "(?<=x:) # Assert position right after 'x:'\n" +
    "[^:]*   # Match any number of characters except colons", 
    Pattern.COMMENTS);
Matcher regexMatcher = regex.matcher(subjectString);
if (regexMatcher.find()) {
    ResultString = regexMatcher.group();
}