3 files changed, 44 insertions, 26 deletions

diff --git a/src/de/danoeh/antennapod/storage/DownloadRequester.java b/src/de/danoeh/antennapod/storage/DownloadRequester.java
index 928b923fd..d977b4a3e 100644
--- a/src/de/danoeh/antennapod/storage/DownloadRequester.java
+++ b/src/de/danoeh/antennapod/storage/DownloadRequester.java
@@ -14,7 +14,7 @@ import de.danoeh.antennapod.feed.FeedFile;
 import de.danoeh.antennapod.feed.FeedImage;
 import de.danoeh.antennapod.feed.FeedMedia;
 import de.danoeh.antennapod.service.download.DownloadService;
-import de.danoeh.antennapod.util.NumberGenerator;
+import de.danoeh.antennapod.util.FileNameGenerator;
 import de.danoeh.antennapod.util.URLChecker;
 
 public class DownloadRequester {
@@ -94,7 +94,8 @@ public class DownloadRequester {
 		}
 	}
 
-	public void downloadMedia(Context context, FeedMedia feedmedia) throws DownloadRequestException {
+	public void downloadMedia(Context context, FeedMedia feedmedia)
+			throws DownloadRequestException {
 		if (feedFileValid(feedmedia)) {
 			download(context, feedmedia,
 					new File(getMediafilePath(context, feedmedia),
@@ -199,7 +200,8 @@ public class DownloadRequester {
 	}
 
 	public String getFeedfileName(Feed feed) {
-		return "feed-" + NumberGenerator.generateLong(feed.getDownload_url());
+		return "feed-"
+				+ FileNameGenerator.generateFileName(feed.getDownload_url());
 	}
 
 	public String getImagefilePath(Context context)
@@ -209,7 +211,8 @@ public class DownloadRequester {
 	}
 
 	public String getImagefileName(FeedImage image) {
-		return "image-" + NumberGenerator.generateLong(image.getDownload_url());
+		return "image-"
+				+ FileNameGenerator.generateFileName(image.getDownload_url());
 	}
 
 	public String getMediafilePath(Context context, FeedMedia media)
@@ -217,7 +220,7 @@ public class DownloadRequester {
 		File externalStorage = getExternalFilesDirOrThrowException(
 				context,
 				MEDIA_DOWNLOADPATH
-						+ NumberGenerator.generateLong(media.getItem()
+						+ FileNameGenerator.generateFileName(media.getItem()
 								.getFeed().getTitle()) + "/");
 		return externalStorage.toString();
 	}
diff --git a/src/de/danoeh/antennapod/util/FileNameGenerator.java b/src/de/danoeh/antennapod/util/FileNameGenerator.java
new file mode 100644
index 000000000..3bc193080
--- /dev/null
+++ b/src/de/danoeh/antennapod/util/FileNameGenerator.java
@@ -0,0 +1,36 @@
+package de.danoeh.antennapod.util;
+
+import java.util.Arrays;
+
+/** Generates valid filenames for a given string. */
+public class FileNameGenerator {
+	
+	private static final char[] ILLEGAL_CHARACTERS = { '/', '\\', '?', '%',
+			'*', ':', '|', '"', '<', '>' };
+	static {
+		Arrays.sort(ILLEGAL_CHARACTERS);
+	}
+	
+	private FileNameGenerator() {
+
+	}
+
+	/**
+	 * This method will return a new string that doesn't contain any illegal
+	 * characters of the given string.
+	 */
+	public static String generateFileName(String string) {
+		StringBuilder builder = new StringBuilder();
+		for (int i = 0; i < string.length(); i++) {
+			char c = string.charAt(i);
+			if (Arrays.binarySearch(ILLEGAL_CHARACTERS, c) < 0) {
+				builder.append(c);
+			}
+		}
+		return builder.toString();
+	}
+
+	public static long generateLong(final String str) {
+		return str.hashCode();
+	}
+}
diff --git a/src/de/danoeh/antennapod/util/NumberGenerator.java b/src/de/danoeh/antennapod/util/NumberGenerator.java
deleted file mode 100644
index ff89180e1..000000000
--- a/src/de/danoeh/antennapod/util/NumberGenerator.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package de.danoeh.antennapod.util;
-
-
-/**Utility class for creating numbers.*/
-public final class NumberGenerator {
-    /** Class shall not be instantiated.*/
-    private NumberGenerator() {
-    }
-
-    /**Logging tag.*/
-    private static final String TAG = "NumberGenerator";
-
-    /** Takes a string and generates a random value out of
-     * the hash-value of that string.
-     *  @param strSeed The string to take for the return value
-     *  @return The generated random value
-     * */
-    public static long generateLong(final String strSeed) {
-        return strSeed.hashCode();
-    }
-}