/*

 * Copyright 2004 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.security.util;

import java.io.File;

import java.io.IOException;

import java.lang.String;

import java.util.StringTokenizer;

import java.net.URL;

import java.net.URLClassLoader;

import java.net.MalformedURLException;

/**

 * A utility class for handle path list

 *

 */

public class PathList {

    /**

     * Utility method for appending path from pathFrom to pathTo.

     *

     * @param pathTo the target path

     * @param pathSource the path to be appended to pathTo

     * @return the resulting path

     */

    public static String appendPath(String pathTo, String pathFrom) {

        if (pathTo == null || pathTo.length() == 0) {

            return pathFrom;

        } else if (pathFrom == null || pathFrom.length() == 0) {

            return pathTo;

        } else {

            return pathTo  + File.pathSeparator + pathFrom;

        }

    }

    /**

     * Utility method for converting a search path string to an array

     * of directory and JAR file URLs.

     *

     * @param path the search path string

     * @return the resulting array of directory and JAR file URLs

     */

    public static URL[] pathToURLs(String path) {

        StringTokenizer st = new StringTokenizer(path, File.pathSeparator);

        URL[] urls = new URL[st.countTokens()];

        int count = 0;

        while (st.hasMoreTokens()) {

            URL url = fileToURL(new File(st.nextToken()));

            if (url != null) {

                urls[count++] = url;

            }

        }

        if (urls.length != count) {

            URL[] tmp = new URL[count];

            System.arraycopy(urls, 0, tmp, 0, count);

            urls = tmp;

        }

        return urls;

    }

    /**

     * Returns the directory or JAR file URL corresponding to the specified

     * local file name.

     *

     * @param file the File object

     * @return the resulting directory or JAR file URL, or null if unknown

     */

    private static URL fileToURL(File file) {

        String name;

        try {

            name = file.getCanonicalPath();

        } catch (IOException e) {

            name = file.getAbsolutePath();

        }

        name = name.replace(File.separatorChar, '/');

        if (!name.startsWith("/")) {

            name = "/" + name;

        }

        // If the file does not exist, then assume that it's a directory

        if (!file.isFile()) {

            name = name + "/";

        }

        try {

            return new URL("file", "", name);

        } catch (MalformedURLException e) {

            throw new IllegalArgumentException("file");

        }

    }

}