001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.data;
031
032import java.io.File;
033
034/**
035 * Utility functions for dealing with data
036 * 
037 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
038 * 
039 */
040public class DataUtils {
041        private static final String DEFAULT_DATA_DIRECTORY_NAME = "Data";
042        private static final String USER_HOME = "user.home";
043        private static final String OPENIMAJ_DATA_DIR = "openimaj.data.dir";
044
045        private DataUtils() {
046        }
047
048        /**
049         * Get the openimaj data directory. This is where things like datasets are
050         * stored. This can be controlled by the <code>openimaj.data.dir</code>
051         * system property. If the property is unset, then this defaults to
052         * <code>$HOME/Data</code> where <code>$HOME</code> is the home directory of
053         * the user who owns the current JVM process.
054         * 
055         * @return The data directory location
056         */
057        public static File getDataDirectory() {
058                File dataDir = null;
059
060                if (System.getProperty(OPENIMAJ_DATA_DIR) != null) {
061                        dataDir = new File(System.getProperty(OPENIMAJ_DATA_DIR));
062                } else {
063                        final String userHome = System.getProperty(USER_HOME);
064                        dataDir = new File(userHome, DEFAULT_DATA_DIRECTORY_NAME);
065                }
066
067                return dataDir;
068        }
069
070        /**
071         * Get the location of the given data file/directory. This will be relative
072         * to the openimaj data directory given by {@link #getDataDirectory()}.
073         * 
074         * @param relativePath
075         *            the relative path the to data
076         * 
077         * @see DataUtils#getDataDirectory()
078         * 
079         * @return The data location
080         */
081        public static File getDataLocation(File relativePath) {
082                return getDataLocation(relativePath.getPath());
083        }
084
085        /**
086         * Get the location of the given data file/directory. This will be relative
087         * to the openimaj data directory given by {@link #getDataDirectory()}.
088         * 
089         * @param relativePath
090         *            the relative path the to data
091         * 
092         * @see DataUtils#getDataDirectory()
093         * 
094         * @return The data location
095         */
096        public static File getDataLocation(String relativePath) {
097                return new File(getDataDirectory(), relativePath);
098        }
099}