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.awt.image.*;
  23 import java.io.*;
  24 import java.net.URL;
  25 import java.net.URLConnection;
  26
  27 public class AltosSiteMapCache extends JLabel {
  28         static final long google_maps_ratelimit_ms = 1200;
  29         // Google limits static map queries to 50 per minute per IP, so
  30         // each query should take at least 1.2 seconds.
  31
  32         public static boolean fetchMap(File file, String url) {
  33                 URL u;
  34                 long startTime = System.nanoTime();
  35
  36                 try {
  37                         u = new URL(url);
  38                 } catch (java.net.MalformedURLException e) {
  39                         return false;
  40                 }
  41
  42                 byte[] data;
  43                 try {
  44                         URLConnection uc = u.openConnection();
  45                         int contentLength = uc.getContentLength();
  46                         InputStream in = new BufferedInputStream(uc.getInputStream());
  47                         int bytesRead = 0;
  48                         int offset = 0;
  49                         data = new byte[contentLength];
  50                         while (offset < contentLength) {
  51                                 bytesRead = in.read(data, offset, data.length - offset);
  52                                 if (bytesRead == -1)
  53                                         break;
  54                                 offset += bytesRead;
  55                         }
  56                         in.close();
  57
  58                         if (offset != contentLength) {
  59                                 return false;
  60                         }
  61                 } catch (IOException e) {
  62                         return false;
  63                 }
  64
  65                 try {
  66                         FileOutputStream out = new FileOutputStream(file);
  67                         out.write(data);
  68                         out.flush();
  69                         out.close();
  70                 } catch (FileNotFoundException e) {
  71                         return false;
  72                 } catch (IOException e) {
  73                         if (file.exists()) {
  74                                 file.delete();
  75                         }
  76                         return false;
  77                 }
  78
  79                 long duration_ms = (System.nanoTime() - startTime) / 1000000;
  80                 if (duration_ms < google_maps_ratelimit_ms) {
  81                         try {
  82                                 Thread.sleep(google_maps_ratelimit_ms - duration_ms);
  83                         } catch (InterruptedException e) {
  84                                 Thread.currentThread().interrupt();
  85                         }
  86                 }
  87
  88                 return true;
  89         }
  90
  91         public static ImageIcon fetchAndLoadMap(File pngfile, String url) {
  92                 if (!pngfile.exists()) {
  93                         if (!fetchMap(pngfile, url)) {
  94                                 return null;
  95                         }
  96                 }
  97                 return loadMap(pngfile, url);
  98         }
  99
 100         public static ImageIcon loadMap(File pngfile, String url) {
 101                 if (!pngfile.exists()) {
 102                         return null;
 103                 }
 104
 105                 try {
 106                         BufferedImage   img;
 107
 108                         img = ImageIO.read(pngfile);
 109                         if (img == null) {
 110                                 System.out.printf("# Can't read pngfile %s\n", pngfile);
 111                                 return null;
 112                         }
 113                         return new ImageIcon(img);
 114                 } catch (IOException e) {
 115                         System.out.printf("# IO error trying to load %s\n", pngfile);
 116                         return null;
 117                 }
 118         }
 119 }