New regular expression feature of Java 5.0

The java.util.regex package has been enhanced in Java 5.0. One nice new feature is the ability to save the results of a find() operation into a MatchResult object. Prior to Java 5.0, you could query a Matcher for the results of the most recent find() , but the results would be overwritten by the next find().

The new MatchResult interface lends itself to code like the following:

import java.util.regex.*;
import java.util.*;

public class FindAll {
    public static void main(String[] args) {
	Pattern pattern = Pattern.compile(args[0]);
	String text = args[1];

	List<MatchResult> results = findAll(pattern, text);
	for(MatchResult r : results) {
	    System.out.printf("Found '%s' at (%d,%d)%n",
			      r.group(), r.start(), r.end());
	}
    }

    public static List<MatchResult> findAll(Pattern pattern, CharSequence text)
    {
	List<MatchResult> results = new ArrayList<MatchResult>();
	Matcher m = pattern.matcher(text);
	while(m.find()) results.add(m.toMatchResult());
	return results;
    }
}

This code also demonstrates generics, the for/in loop, and the printf() method, all of which are also new in Java 5.0