git.gag.com Git - fw/altos/blob - altosui/AltosSiteMapCache.java

   1 /*
   2  * Copyright © 2010 Anthony Towns <aj@erisian.com.au>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 package altosui;
  19
  20 import javax.swing.*;
  21 import javax.imageio.ImageIO;
  22 import java.io.*;
  23 import java.net.URL;
  24 import java.net.URLConnection;
  25
  26 public class AltosSiteMapCache extends JLabel {
  27         public static boolean fetchMap(File file, String url) {
  28                 URL u;
  29
  30                 try {
  31                         u = new URL(url);
  32                 } catch (java.net.MalformedURLException e) {
  33                         return false;
  34                 }
  35
  36                 byte[] data;
  37                 try {
  38                         URLConnection uc = u.openConnection();
  39                         int contentLength = uc.getContentLength();
  40                         InputStream in = new BufferedInputStream(uc.getInputStream());
  41                         int bytesRead = 0;
  42                         int offset = 0;
  43                         data = new byte[contentLength];
  44                         while (offset < contentLength) {
  45                                 bytesRead = in.read(data, offset, data.length - offset);
  46                                 if (bytesRead == -1)
  47                                         break;
  48                                 offset += bytesRead;
  49                         }
  50                         in.close();
  51
  52                         if (offset != contentLength) {
  53                                 return false;
  54                         }
  55                 } catch (IOException e) {
  56                         return false;
  57                 }
  58
  59                 try {
  60                         FileOutputStream out = new FileOutputStream(file);
  61                         out.write(data);
  62                         out.flush();
  63                         out.close();
  64                 } catch (FileNotFoundException e) {
  65                         return false;
  66                 } catch (IOException e) {
  67                         if (file.exists()) {
  68                                 file.delete();
  69                         }
  70                         return false;
  71                 }
  72                 return true;
  73         }
  74
  75         public static ImageIcon fetchAndLoadMap(File pngfile, String url) {
  76                 if (!pngfile.exists()) {
  77                         if (!fetchMap(pngfile, url)) {
  78                                 return null;
  79                         }
  80                 }
  81                 return loadMap(pngfile, url);
  82         }
  83
  84         public static ImageIcon loadMap(File pngfile, String url) {
  85                 if (!pngfile.exists()) {
  86                         return null;
  87                 }
  88
  89                 try {
  90                         return new ImageIcon(ImageIO.read(pngfile));
  91                 } catch (IOException e) {
  92                         System.out.printf("# IO error trying to load %s\n", pngfile);
  93                         return null;
  94                 }
  95         }
  96 }