Image caching

src/uk/co/md87/evetool/ImageManager.java

@@ -25,7 +25,6 @@ package uk.co.md87.evetool;
 import java.awt.Image;
 import java.io.File;
 import java.io.IOException;
-import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -34,6 +33,7 @@ import java.util.logging.Logger;
 
 import javax.imageio.ImageIO;
 
+import uk.co.md87.evetool.api.io.Downloader;
 import uk.co.md87.evetool.api.io.QueueSizeListener;
 
 /**
@@ -45,6 +45,8 @@ public class ImageManager {
 
     protected static final List<String> REQUESTS = new ArrayList<String>();
 
+    protected static final String ILLEGAL_CHARS = "[\\\\\"/:\\*\\?\"<>\\|]";
+
     private static final List<QueueSizeListener> listeners = new ArrayList<QueueSizeListener>();
 
     private static final AtomicInteger queueSize = new AtomicInteger(0);
@@ -63,6 +65,7 @@ public class ImageManager {
 
     public Image getImage(final ImageType type, final Object ... arguments) throws IOException {
         final String url = type.getUrl(arguments);
+        final String cacheUrl = url.replaceAll(ILLEGAL_CHARS, "_");
 
         synchronized (REQUESTS) {
             fireQueueSizeChange(queueSize.incrementAndGet());
@@ -79,8 +82,13 @@ public class ImageManager {
         }
 
         try {
-            final Image res = ImageIO.read(new URL(url));
-            return res;
+            final File file = new File(cacheDir, cacheUrl);
+            
+            if (!file.exists()) {
+                Downloader.downloadPage(url, file);
+            }
+
+            return ImageIO.read(file);
         } finally {
             synchronized (REQUESTS) {
                 fireQueueSizeChange(queueSize.decrementAndGet());

src/uk/co/md87/evetool/api/io/Downloader.java

@@ -24,7 +24,10 @@ package uk.co.md87.evetool.api.io;
 
 import java.io.BufferedReader;
 import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.UnsupportedEncodingException;
 import java.net.URL;
@@ -113,6 +116,35 @@ public final class Downloader {
 
         return data.length() == 0 ? "" : data.substring(1);
     }
+
+    /**
+     * Downloads the specified page to disk.
+     *
+     * @param url The URL to retrieve
+     * @param file The file to save the page to
+     * @throws java.io.IOException If there's an I/O error while downloading
+     */
+    public static void downloadPage(final String url, final File file) throws IOException {
+
+        final URLConnection urlConn = getConnection(url, "");
+
+        final FileOutputStream output = new FileOutputStream(file);
+        final InputStream input = urlConn.getInputStream();
+
+        final byte[] buffer = new byte[512];
+        int count;
+
+        do {
+            count = input.read(buffer);
+
+            if (count > 0) {
+                output.write(buffer, 0, count);
+            }
+        } while (count > 0);
+
+        input.close();
+        output.close();
+    }
         
     /**
      * Creates an URL connection for the specified URL and data.