Brace expansion, alternative to https://github.com/AndersDJohnson/brace-expansion-java.

BraceExpansion.java

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

/**
 * From http://rosettacode.org/wiki/Brace_expansion#Java
 * 
 * May integrate with https://github.com/AndersDJohnson/brace-expansion-java.
 */
public class BraceExpansion {

	public static List<String> expand(String s) {
		return expandR("", s, "", new ArrayList<String>());
	}

	private static List<String> expandR(String pre, String s, String suf, List<String> list) {
		int i1 = -1, i2 = 0;
		String noEscape = s.replaceAll("([\\\\]{2}|[\\\\][,}{])", "  ");
		StringBuilder sb = null;

		outer:
		while ((i1 = noEscape.indexOf('{', i1 + 1)) != -1) {
			i2 = i1 + 1;
			sb = new StringBuilder(s);
			System.out.println("s=" + s);
			for (int depth = 1; i2 < s.length() && depth > 0; i2++) {
				char c = noEscape.charAt(i2);
				Character c2 = null;
				int i3 = i2 + 1;
				try {
					c2 = noEscape.charAt(i3);
				}
				catch (IndexOutOfBoundsException e) {}

				depth = (c == '{') ? ++depth : depth;
				depth = (c == '}') ? --depth : depth;
				if (c == ',' && depth == 1) {
					sb.setCharAt(i2, '\u0000');
				}
				else if (c == '}' && depth == 0 && sb.indexOf("\u0000") != -1)
					break outer;
			}
		}

		if (i1 == -1) {
			if (suf.length() > 0)
				expandR(pre + s, suf, "", list);
			else {
				list.add(pre + s + suf);
			}
		} else {
			for (String m : sb.substring(i1 + 1, i2).split("(?:\u0000|\u3040)", -1)) {
				System.out.println("m=" + m);
				expandR(pre + s.substring(0, i1), m, s.substring(i2 + 1) + suf, list);
			}
		}

		return ranges(list);
	}

	private static List<String> ranges(List<String> list) {
		List<String> newList = new ArrayList<String>();
		Pattern p = Pattern.compile("\\{(\\d+)\\.\\.(\\d+)\\}");
		for (String st : list) {
			Matcher m = p.matcher(st);
			boolean found = false;
			while (m.find()) {
				found = true;
				Integer l = Integer.parseInt(m.group(1));
				Integer r = Integer.parseInt(m.group(2));
				for (; l <= r; ++l) {
					newList.add(st.substring(0, m.start()) + l.toString() + st.substring(m.end()));
				}
				newList = ranges(newList);
			}
			if (! found) {
				newList.add(st);
			}
		}
		return newList;
	}

	public static void testRanges() {
		expand("a{0..1}b{1..9}c");
	}
}