Java repetitive pattern matching

Question

I am trying to get each of the repetitive matches of a simple regular expression in Java:

(\\[[^\\[]*\\])*

which matches any string enclosed in [], as long as it does not contain the [ character. For example, it would match

[a][nice][repetitive][pattern]

There is no prior knowledge of how many such groups exist and I cannot find a way of accessing the individual matching groups via a pattern matcher, i.e. can't get

[a], [nice], [repetitive], [pattern]

(or, even better, the text without the brackets), in 4 different strings.

Using pattern.matcher() I always get the last group.

Surely there must be a simple way of doing this in Java, which I am missing?

Thanks for any help.

pap · Accepted Answer · 2011-06-14 07:34:30Z

5

while (matcher.find()) {
   System.out.println(matcher.group(1));
}

http://download.oracle.com/javase/6/docs/api/java/util/regex/Matcher.html#find%28%29

answered Jun 14, 2011 at 7:34

pap

27.7k6 gold badges44 silver badges46 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Thresh · Accepted Answer · 2011-06-14 07:37:26Z

5

    String string = "[a][nice][repetitive][pattern]";
    String regexp = "\\[([^\\[]*)\\]";
    Pattern pattern = Pattern.compile(regexp);
    Matcher matcher = pattern.matcher(string);
    while (matcher.find()) {
        System.out.println(matcher.group(1));
    }

answered Jun 14, 2011 at 7:37

Thresh

95314 silver badges23 bronze badges

1 Comment

Muhammad Gelbana Over a year ago

Would you please explain your regexp ?. Thank you.

Peter Lawrey · Accepted Answer · 2011-06-14 08:02:44Z

2

I would use split

String string = "[a][nice][repetitive][pattern]";
String[] words = string.substring(1, string.length()-1).split("\\]\\[");
System.out.println(Arrays.toString(words));

prints

[a, nice, repetitive, pattern]

answered Jun 14, 2011 at 8:02

Peter Lawrey

535k83 gold badges770 silver badges1.2k bronze badges

Comments

hoipolloi · Accepted Answer · 2011-06-14 07:49:57Z

1

Here's my attempt :)

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Foo {
    public static void main(String[] args) {
        final String text = "[a][nice][repetitive][pattern]";
        System.out.println(getStrings(text)); // Prints [a, nice, repetitive, pattern]
    }

    private static final Pattern pattern = Pattern.compile("\\[([^\\]]+)]");

    public static List<String> getStrings(final String text) {
        final List<String> strings = new ArrayList<String>();
        final Matcher matcher = pattern.matcher(text);
        while(matcher.find()) {
            strings.add(matcher.group(1));
        }
        return strings;
    }

}

answered Jun 14, 2011 at 7:49

hoipolloi

8,0442 gold badges29 silver badges28 bronze badges

1 Comment

Muhammad Gelbana Over a year ago

Would you please explain your regular expression ?

Collectives™ on Stack Overflow

Java repetitive pattern matching

4 Answers 4

Comments

1 Comment

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

1 Comment

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related