| gvSIG desktop 1

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2006 Prodevelop and Generalitat Valenciana.

 *

 * 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.

 *

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

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *   Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *   +34 963862235

 *   gvsig@gva.es

 *   http://www.gvsig.gva.es

 *

 *    or

 *

 *   Prodevelop Integraci?n de Tecnolog?as SL

 *   Conde Salvatierra de ?lava , 34-10

 *   46004 Valencia

 *   Spain

 *

 *   +34 963 510 612

 *   +34 963 510 968

 *   gis@prodevelop.es

 *   http://www.prodevelop.es

 *

 *    or

 *

 *   Instituto de Rob?tica

 *   Apartado de correos 2085

 *   46071 Valencia

 *   (Spain)

 *   

 *   +34 963 543 577

 *   jjordan@robotica.uv.es

 *   http://robotica.uv.es

 *   

 */

package es.prodevelop.gvsig.mobile.fmap.util.download;

import java.io.DataInputStream;

import java.io.File;

import java.net.URL;

import java.util.ArrayList;

import org.apache.log4j.Logger;

import es.prodevelop.gvsig.mobile.fmap.util.Utils;

/**

 * Utility class to download resources from the internet.

 * 

 * @see es.prodevelop.gvsig.mobile.fmap.util.download.DownloadTask

 * @see es.prodevelop.gvsig.mobile.fmap.util.download.DownloadException

 * 

 * @author jldominguez

 *

 */

public class Downloader {

        private static final long MAX_TIME_ALLOWED = 12000;

        private static final long MAX_TIME_ALLOWED_STEP = 500;

        public static String CACHED_FILES_ROOT_PATH = File.separator;

        private static Logger logger = Logger.getLogger(Downloader.class);

        /**

         * This method downloads the resource into a local File or as an array of bytes in memory.

         * 

         * @param u the URL

         * @param exte the extension (used if it's going to be a file)

         * @param type download type (file/array)

         * @param cachedFilesSubfolder folder destination (used when it's a file)

         * @param filePath file path on the folder destination

         * @param use_hash whether a hash funcrtion must be used to code the file name

         * @return an object file or an array of bytes

         * @throws DownloadException

         */

        public static Object downloadObjectCancel(

                        URL u,

                        String exte,

                        int type,

                        String cachedFilesSubfolder,

                        String filePath,

                        boolean use_hash) throws DownloadException {

                if (u == null) {

                        throw new DownloadException("Bad URL");

                }

                File cachedFile = null;

                if (type == DownloadTask.FILE) {

                        if (use_hash) {

                                cachedFile = Utils.getHashCacheFileForUrl(

                                                u, CACHED_FILES_ROOT_PATH, cachedFilesSubfolder, exte);

                        } else {

                                cachedFile = new File(CACHED_FILES_ROOT_PATH

                                                + File.separator

                                                + cachedFilesSubfolder

                                                + File.separator

                                                + filePath);

                        }

                        if (cachedFile.exists()) {

                                logger.debug("CACHED FILE EXISTED !!!");

                                return cachedFile; 

                        }

                }

                DownloadTask task = new DownloadTask(u, exte, type, cachedFile);

                Thread down_thread = new Thread(task);

                down_thread.start();

                long time_out = MAX_TIME_ALLOWED;

                while ((time_out > 0) && (!task.isDone())) {

                        try { Thread.sleep(500); } catch (InterruptedException e) {}

                        time_out = time_out - MAX_TIME_ALLOWED_STEP;

                }

                if (task.isDone()) {

                        Object resp = task.getDownloadedObject();

                        if (resp == null) {

                                task.cancel();

                                throw new DownloadException("error");

                        } else {

                                return resp;

                        }

                } else {

                        task.cancel();

                        throw new DownloadException("timeout");

                }

        }

        /**

         * This method downloads a URL as a byte array. It does no participate in

         * the file cache, so should be avoided

         * 

         * @param u

         * @param exte

         * @return the resource as a bute array

         * @throws DownloadException

         */

        public static byte[] getByteArray(URL u, String exte) throws DownloadException {

                ArrayList byteArraysList = new ArrayList(); 

                try {

                        byte[] buffer = new byte[1024*4];

                        DataInputStream is = new DataInputStream(u.openStream());

                        int full_size = 0;

                        for (int i = is.read(buffer); i>0; i = is.read(buffer)){

                                byteArraysList.add(new Integer(i));

                                byteArraysList.add(buffer.clone());

                                full_size = full_size + i;

                        }

                        byteArraysList.add(new Integer(full_size));

                } catch (Exception e) {

                        if (e.getMessage().indexOf("403") != -1) {

                                throw new DownloadException("403");

                        } else {

                                throw new DownloadException(e.getMessage());

                        }

                }

                return mergeBytes(byteArraysList);

        }

        private static byte[] mergeBytes(ArrayList byteArraysList) {

                int array_size = byteArraysList.size(); 

                int total_size =  ((Integer) byteArraysList.get(array_size - 1)).intValue();

                int n = array_size / 2;

                int item_size = 0;

                byte[] item_bytes = null;

                byte[] resp = new byte[total_size];

                int index = 0;

                for (int i=0; i<n; i++) {

                        logger.debug("MERGE BYTES: i = " + i);

                        item_size = ((Integer) byteArraysList.get(2 * i)).intValue();

                        item_bytes = (byte[]) byteArraysList.get(2 * i + 1);

                        System.arraycopy(item_bytes, 0, resp, index, item_size);

                        index = index + item_size;

                }

                return resp;

        }

}