+++ /dev/null
-package tim.prune.gui.map;
-
-import java.awt.Image;
-import java.awt.Toolkit;
-import java.awt.image.ImageObserver;
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.net.URL;
-import java.net.URLConnection;
-import java.util.HashSet;
-
-import tim.prune.GpsPrune;
-
-/**
- * Class to control the reading and saving of map tiles
- * to a cache on disk
- */
-public class DiskTileCacher implements Runnable
-{
- /** URL to get image from */
- private URL _url = null;
- /** File to save image to */
- private File _file = null;
- /** Observer to be notified */
- private ImageObserver _observer = null;
- /** Time limit to cache images for */
- private static final long CACHE_TIME_LIMIT = 20 * 24 * 60 * 60 * 1000; // 20 days in ms
- /** Hashset of all blocked / 404 tiles to avoid requesting them again */
- private static final HashSet<String> BLOCKED_URLS = new HashSet<String>();
-
- /**
- * Private constructor
- * @param inUrl URL to get
- * @param inFile file to save to
- */
- private DiskTileCacher(URL inUrl, File inFile, ImageObserver inObserver)
- {
- _url = inUrl;
- _file = inFile;
- _observer = inObserver;
- }
-
- /**
- * Get the specified tile from the disk cache
- * @param inBasePath base path to whole disk cache
- * @param inTilePath relative path to requested tile
- * @return tile image if available, or null if not there
- */
- public static MapTile getTile(String inBasePath, String inTilePath)
- {
- if (inBasePath == null) {return null;}
- File tileFile = new File(inBasePath, inTilePath);
- Image image = null;
- if (tileFile.exists() && tileFile.canRead() && tileFile.length() > 0)
- {
- long fileStamp = tileFile.lastModified();
- boolean isExpired = ((System.currentTimeMillis()-fileStamp) > CACHE_TIME_LIMIT);
- try
- {
- image = Toolkit.getDefaultToolkit().createImage(tileFile.getAbsolutePath());
- return new MapTile(image, isExpired);
- }
- catch (Exception e) {
- System.err.println("createImage: " + e.getClass().getName() + " _ " + e.getMessage());
- }
- }
- return null;
- }
-
- /**
- * Save the specified image tile to disk
- * @param inUrl url to get image from
- * @param inBasePath base path to disk cache
- * @param inTilePath relative path to this tile
- * @param inObserver observer to inform when load complete
- */
- public static void saveTile(URL inUrl, String inBasePath, String inTilePath, ImageObserver inObserver)
- {
- if (inBasePath == null || inTilePath == null) {return;}
- // save file if possible
- File basePath = new File(inBasePath);
- if (!basePath.exists() || !basePath.isDirectory() || !basePath.canWrite()) {
- // Can't write to base path
- return;
- }
- File tileFile = new File(basePath, inTilePath);
- // Check if this file is already being loaded
- if (isBeingLoaded(tileFile)) {return;}
- // Check if it has already failed
- if (BLOCKED_URLS.contains(inUrl.toString())) {return;}
-
- File dir = tileFile.getParentFile();
- // Start a new thread to load the image if necessary
- if ((dir.exists() || dir.mkdirs()) && dir.canWrite())
- {
- new Thread(new DiskTileCacher(inUrl, tileFile, inObserver)).start();
- }
- }
-
- /**
- * Check whether the given tile is already being loaded
- * @param inFile desired file
- * @return true if temporary file with this name exists
- */
- private static boolean isBeingLoaded(File inFile)
- {
- File tempFile = new File(inFile.getAbsolutePath() + ".temp");
- if (!tempFile.exists()) {
- return false;
- }
- // File exists, so check if it was created recently
- final long fileAge = System.currentTimeMillis() - tempFile.lastModified();
- return fileAge < 1000000L; // overwrite if the temp file is still there after 1000s
- }
-
- /**
- * Run method for loading URL asynchronously and saving to file
- */
- public void run()
- {
- boolean finished = false;
- InputStream in = null;
- FileOutputStream out = null;
- File tempFile = new File(_file.getAbsolutePath() + ".temp");
- // Use a synchronized block across all threads to make sure this url is only fetched once
- synchronized (DiskTileCacher.class)
- {
- if (tempFile.exists()) {tempFile.delete();}
- try {
- if (!tempFile.createNewFile()) {return;}
- }
- catch (Exception e) {return;}
- }
- try
- {
- // Open streams from URL and to file
- out = new FileOutputStream(tempFile);
- //System.out.println("Opening URL: " + _url.toString());
- // Set http user agent on connection
- URLConnection conn = _url.openConnection();
- conn.setRequestProperty("User-Agent", "GpsPrune v" + GpsPrune.VERSION_NUMBER);
- in = conn.getInputStream();
- int d = 0;
- // Loop over each byte in the stream (maybe buffering is more efficient?)
- while ((d = in.read()) >= 0) {
- out.write(d);
- }
- finished = true;
- } catch (IOException e) {
- System.err.println("ioe: " + e.getClass().getName() + " - " + e.getMessage());
- BLOCKED_URLS.add(_url.toString());
- }
- finally
- {
- // clean up files
- try {in.close();} catch (Exception e) {} // ignore
- try {out.close();} catch (Exception e) {} // ignore
- if (!finished) {
- tempFile.delete();
- }
- }
- // Move temp file to desired file location
- if (tempFile.exists() && !tempFile.renameTo(_file))
- {
- // File couldn't be moved - delete both to be sure
- tempFile.delete();
- _file.delete();
- }
- // Tell parent that load is finished (parameters ignored)
- _observer.imageUpdate(null, ImageObserver.ALLBITS, 0, 0, 0, 0);
- }
-}
projects / GpsPrune.git / blobdiff