regex - Find pattern in files with java 8

Question

consider I have a file like (just an excerpt)

name: 'foobar'

I like to retrieve foobar when I discover the line with name.

My current approach is

Pattern m = Pattern.compile("name: '(.+)'");
try (Stream<String> lines = Files.lines(ruleFile)) {
    Optional<String> message = lines.filter(m.asPredicate()).findFirst();
    if (message.isPresent()) {
        Matcher matcher = m.matcher(message.get());
        matcher.find();
        String group = matcher.group(1);
        System.out.println(group);
    }
}

which looks not nice. The excessive use of the pattern and matcher seems wrong.

Is there a easier/better way ? Especially if I have multiple keys I like to search like this ?

Answer 1

I would expect something more like this, to avoid matching the pattern twice:

Pattern p = Pattern.compile("name: '([^']*)'");
lines.map(p::matcher)
     .filter(Matcher::matches)
     .findFirst()
     .ifPresent(matcher -> System.out.println(matcher.group(1)));

That is, for each string's matcher, get the first one that matches, for that one print out the first group.