sigil/bld-ivy/src/org/cauldron/bld/ivy/FindUtil.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.cauldron.bld.ivy;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;

public class FindUtil {
	static final String WILD_ANY = "[^.].*";
	static final String WILD_ONE = "[^.][^;]*";    // WILD_ONE.endsWith(WILD_ANY) == false
	
	// example pattern: ${repository}/projects/abc*/*/project.sigil
	public static Collection<File> findFiles(String pattern) throws IOException {
		int star = pattern.indexOf("*");
		if (star == -1) {
			throw new IOException("pattern doesn't contain '*': " + pattern);
		}
		int slash = pattern.lastIndexOf('/', star);
		
		String regex = pattern.substring(slash + 1);
		regex = regex.replaceAll("\\*\\*", "-wildany-");
		regex = regex.replaceAll("\\*", "-wildone-");
		regex = regex.replaceAll("-wildany-", WILD_ANY);
		regex = regex.replaceAll("-wildone-", WILD_ONE);
		
		String[] patterns = regex.split("/");
		
		ArrayList<File> list = new ArrayList<File>();
		File root = new File(pattern.substring(0, slash));
		
		if (root.isDirectory()) {
    		findFiles(root, 0, patterns, list);
		} else {
			throw new IOException("pattern root directory does not exist: " + root);
		}
		
		return list;
	}
	
	private static void findFiles(File dir, int level, String[] patterns, Collection<File> list) {
		final String filePattern = patterns[patterns.length-1];
		final String dirPattern;
		
		if (level < patterns.length-1) {
			dirPattern = patterns[level];
		} else {
			dirPattern = "/";    // impossible to match marker
		}
		
		final boolean stillWild;
		if ((level > 0) && (level < patterns.length) && patterns[level-1].endsWith(WILD_ANY)) {
			stillWild = true;
		} else {
			stillWild = false;
		}
		
		for (File path : dir.listFiles(new FileFilter() {
			public boolean accept(File pathname) {
				String name = pathname.getName();
				if (pathname.isDirectory()) {
					return name.matches(dirPattern) || (stillWild && name.matches(WILD_ANY));
				} else if (dirPattern.equals("/") || dirPattern.equals(WILD_ANY)) {
					return name.matches(filePattern);
				} else {
					return false;
				}
			}
		})) {
			if (path.isDirectory()) {
				int inc = path.getName().matches(dirPattern) ? 1 : 0;
				findFiles(path, level + inc, patterns, list);
			} else {
				list.add(path);
			}
		}
	}
}