Subversion Repositories mkgmap

/*
 * Copyright (C) 2007 Steve Ratcliffe
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  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.
 *
 *
 * Author: Steve Ratcliffe
 * Create date: 02-Sep-2007
 */
package uk.me.parabola.mkgmap.reader.plugin;

import java.util.ArrayList;
import java.util.List;

import uk.me.parabola.mkgmap.general.LoadableMapDataSource;
import uk.me.parabola.mkgmap.reader.osm.xml.Osm5MapDataSource;

/**
 * Class to find the correct map reader to use, based on the type of the file
 * to be read.
 *
 * Allows new map readers to be registered, the map readers are in charge of
 * recognising file formats that they can deal with.
 *
 * @author Steve Ratcliffe
 */
public class MapReader {

        private static final List<Class<? extends LoadableMapDataSource>> loaders;

        static {
                String[] sources = {
                                "uk.me.parabola.mkgmap.reader.osm.bin.OsmBinMapDataSource",
                                "uk.me.parabola.mkgmap.reader.osm.o5m.O5mBinMapDataSource",
                                "uk.me.parabola.mkgmap.reader.polish.PolishMapDataSource",
                                "uk.me.parabola.mkgmap.reader.test.ElementTestDataSource",

                                // must be last as it is the default
                                "uk.me.parabola.mkgmap.reader.osm.xml.Osm5MapDataSource",
                };

                loaders = new ArrayList<Class<? extends LoadableMapDataSource>>();

                for (String source : sources) {
                        try {
                                @SuppressWarnings({"unchecked"})
                                Class<? extends LoadableMapDataSource> c = (Class<? extends LoadableMapDataSource>) Class.forName(source);
                                loaders.add(c);
                        } catch (ClassNotFoundException e) {
                                // not available, try the rest
                        } catch (NoClassDefFoundError e) {
                                // not available, try the rest
                        }
                }
        }

        /**
         * Return a suitable map reader.  The name of the resource to be read is
         * passed in.  This is usually a file name, but could be something else.
         *
         * @param name The resource name to be read.
         * @return A LoadableMapDataSource that is capable of reading the resource.
         */
        public static LoadableMapDataSource createMapReader(String name) {
                for (Class<? extends LoadableMapDataSource> loader : loaders) {
                        try {
                                LoadableMapDataSource src = loader.newInstance();
                                if (name != null && src.isFileSupported(name))
                                        return src;
                        } catch (InstantiationException e) {
                                // try the next one.
                        } catch (IllegalAccessException e) {
                                // try the next one.
                        } catch (NoClassDefFoundError e) {
                                // try the next one
                        }
                }

                // Give up and assume it is in the XML format. If it isn't we will get an
                // error soon enough anyway.
                return new Osm5MapDataSource();
        }
}