    001/* ========================================================================
    002 * JCommon : a free general purpose class library for the Java(tm) platform
    003 * ========================================================================
    004 *
    005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
    006 *
    007 * Project Info:  http://www.jfree.org/jcommon/index.html
    008 *
    009 * This library is free software; you can redistribute it and/or modify it
    010 * under the terms of the GNU Lesser General Public License as published by
    011 * the Free Software Foundation; either version 2.1 of the License, or
    012 * (at your option) any later version.
    013 *
    014 * This library is distributed in the hope that it will be useful, but
    015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
    017 * License for more details.
    018 *
    019 * You should have received a copy of the GNU Lesser General Public
    020 * License along with this library; if not, write to the Free Software
    021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
    022 * USA.
    023 *
    024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025 * in the United States and other countries.]
    026 *
    027 * ------------------
    028 * FileUtilities.java
    029 * ------------------
    030 * (C) Copyright 2000-2004, by Object Refinery Limited.
    031 *
    032 * Original Author:  David Gilbert (for Object Refinery Limited);
    033 * Contributor(s):   -;
    034 *
    035 * $Id: FileUtilities.java,v 1.5 2005/10/18 13:16:02 mungady Exp $
    036 *
    037 * Changes (from 5-Nov-2001)
    038 * -------------------------
    039 * 05-Nov-2001 : Changed package to com.jrefinery.io.* (DG);
    040 * 04-Mar-2002 : Renamed Files.java --> FileUtilities.java (DG);
    041 * 10-Oct-2002 : Fixed errors reported by Checkstyle (DG);
    042 *
    043 */
    044
    045package org.jfree.io;
    046
    047import java.io.File;
    048import java.util.StringTokenizer;
    049
    050/**
    051 * A class containing useful utility methods relating to files.
    052 *
    053 * @author David Gilbert
    054 */
    055public class FileUtilities {
    056
    057    /**
    058     * To prevent unnecessary instantiation.
    059     */
    060    private FileUtilities() {
    061    }
    062
    063    /**
    064     * Returns a reference to a file with the specified name that is located
    065     * somewhere on the classpath.  The code for this method is an adaptation
    066     * of code supplied by Dave Postill.
    067     *
    068     * @param name  the filename.
    069     *
    070     * @return a reference to a file or <code>null</code> if no file could be found.
    071     */
    072    public static File findFileOnClassPath(final String name) {
    073
    074        final String classpath = System.getProperty("java.class.path");
    075        final String pathSeparator = System.getProperty("path.separator");
    076
    077        final StringTokenizer tokenizer = new StringTokenizer(classpath, pathSeparator);
    078
    079        while (tokenizer.hasMoreTokens()) {
    080            final String pathElement = tokenizer.nextToken();
    081
    082            final File directoryOrJar = new File(pathElement);
    083            final File absoluteDirectoryOrJar = directoryOrJar.getAbsoluteFile();
    084
    085            if (absoluteDirectoryOrJar.isFile()) {
    086                final File target = new File(absoluteDirectoryOrJar.getParent(), name);
    087                if (target.exists()) {
    088                    return target;
    089                }
    090            }
    091            else {
    092                final File target = new File(directoryOrJar, name);
    093                if (target.exists()) {
    094                    return target;
    095                }
    096            }
    097
    098        }
    099        return null;
    100
    101    }
    102
    103}