net.sourceforge.atunes.kernel.modules.playlist.M3UPlayListReader.java Source code

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Here is the source code for net.sourceforge.atunes.kernel.modules.playlist.M3UPlayListReader.java

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/*
 * aTunes
 * Copyright (C) Alex Aranda, Sylvain Gaudard and contributors
 *
 * See http://www.atunes.org/wiki/index.php?title=Contributing for information about contributors
 *
 * http://www.atunes.org
 * http://sourceforge.net/projects/atunes
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 for more details.
 */

package net.sourceforge.atunes.kernel.modules.playlist;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import net.sourceforge.atunes.model.IOSManager;
import net.sourceforge.atunes.utils.ClosingUtils;
import net.sourceforge.atunes.utils.Logger;
import net.sourceforge.atunes.utils.StringUtils;

import org.apache.commons.io.IOUtils;

/**
 * Reads M3U play lists
 * 
 * @author alex
 * 
 */
public class M3UPlayListReader {

    private static final String HTTP_PREFIX = "http://";

    /** The Constant M3U_START_COMMENT. */
    private static final String M3U_START_COMMENT = "#";

    /** The Constant M3U_UNIX_ABSOLUTE_PATH. */
    private static final String M3U_UNIX_ABSOLUTE_PATH = "/";

    /** The Constant M3U_WINDOWS_ABSOLUTE_PATH. */
    private static final String M3U_WINDOWS_ABSOLUTE_PATH = ":\\";

    /** The Constant UNC_ABSOLUTE_PATH. */
    private static final String M3U_UNC_ABSOLUTE_PATH = "\\\\";

    private IOSManager osManager;

    /**
     * @param osManager
     */
    public void setOsManager(final IOSManager osManager) {
        this.osManager = osManager;
    }

    List<String> read(final File file) {
        FileReader fr = null;
        try {
            fr = new FileReader(file);
            List<String> lines = readUntilFirstUncommentedLine(IOUtils.readLines(fr));

            if (!lines.isEmpty()) {
                String firstLine = lines.get(0);

                if (isFormatSupported(firstLine)) {
                    return readLines(lines, file.getParent() + this.osManager.getFileSeparator(),
                            isRelativePaths(firstLine));
                }
            }
        } catch (IOException e) {
            Logger.error(e);
        } finally {
            ClosingUtils.close(fr);
        }
        return Collections.emptyList();
    }

    private List<String> readLines(final List<String> lines, final String m3uPath, final boolean isRelative) {
        List<String> result = new ArrayList<String>();
        for (String line : lines) {
            if (!line.startsWith(M3U_START_COMMENT) && !line.isEmpty()) {
                String lineProcessed;
                if (isRelative) {
                    // The path is relative! We must add it to the filename
                    // But if entries are HTTP URLS then don't add any path
                    lineProcessed = line.startsWith(HTTP_PREFIX) ? line : StringUtils.getString(m3uPath, line);
                } else {
                    lineProcessed = line;
                }
                result.add(lineProcessed);
            }
        }
        return result;
    }

    /**
     * @param firstLine
     * @return true if line is valid
     */
    private boolean isFormatSupported(final String firstLine) {
        // Let's check if we are at least using the right OS. Maybe a message
        // should be returned, but for now it doesn't. UNC paths are allowed for
        // all OS
        if (!isRelativePaths(firstLine)
                && (isWindowsAndUnixAbsolutePath(firstLine) || isNotWindowsAndWindowsAbsolutePath(firstLine))) {
            return false;
        }
        return true;
    }

    /**
     * @param firstLine
     * @return
     */
    private boolean isNotWindowsAndWindowsAbsolutePath(final String firstLine) {
        return (!this.osManager.isWindows() && firstLine.startsWith(M3U_WINDOWS_ABSOLUTE_PATH, 1));
    }

    /**
     * @param firstLine
     * @return
     */
    private boolean isWindowsAndUnixAbsolutePath(final String firstLine) {
        return (this.osManager.isWindows() && firstLine.startsWith(M3U_UNIX_ABSOLUTE_PATH));
    }

    /**
     * @param firstLine
     * @return true if line is valid
     */
    private boolean isRelativePaths(final String firstLine) {
        // First absolute path. Windows path detection is very rudimentary, but
        // should work
        if (firstLine.startsWith(M3U_WINDOWS_ABSOLUTE_PATH, 1) || firstLine.startsWith(M3U_UNIX_ABSOLUTE_PATH)
                || firstLine.startsWith(M3U_UNC_ABSOLUTE_PATH)) {
            return false;
        }
        return true;
    }

    private List<String> readUntilFirstUncommentedLine(final List<String> lines) {
        int i = 0;
        for (String line : lines) {
            i++;
            if (line.startsWith(M3U_START_COMMENT)) {
                break;
            }
        }
        return lines.subList(i, lines.size());
    }
}