Refresh at least every 3 days

3 files changed, 28 insertions, 3 deletions

diff --git a/core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java b/core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java
index 6bfd9b4a0..30309192f 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/service/download/HttpDownloader.java
@@ -21,6 +21,7 @@ import java.net.HttpURLConnection;
 import java.net.SocketTimeoutException;
 import java.net.URI;
 import java.net.UnknownHostException;
+import java.util.Date;
 
 import de.danoeh.antennapod.core.BuildConfig;
 import de.danoeh.antennapod.core.ClientConfig;
@@ -64,6 +65,15 @@ public class HttpDownloader extends Downloader {
             final URI uri = URIUtil.getURIFromRequestUrl(request.getSource());
             Request.Builder httpReq = new Request.Builder().url(uri.toURL())
                     .header("User-Agent", ClientConfig.USER_AGENT);
+            if(request.getIfModifiedSince() > 0) {
+                long threeDaysAgo = System.currentTimeMillis() - 1000*60*60*24*3;
+                if(request.getIfModifiedSince() > threeDaysAgo) {
+                    Date date = new Date(request.getIfModifiedSince());
+                    String httpDate = HttpDate.format(date);
+                    Log.d(TAG, "addHeader(\"If-Modified-Since\", \"" + httpDate + "\")");
+                    httpReq.addHeader("If-Modified-Since", httpDate);
+                }
+            }
 
             // add authentication information
             String userInfo = uri.getUserInfo();
@@ -96,6 +106,12 @@ public class HttpDownloader extends Downloader {
             if (BuildConfig.DEBUG)
                 Log.d(TAG, "Response code is " + response.code());
 
+            if(!response.isSuccessful() && response.code() == HttpURLConnection.HTTP_NOT_MODIFIED) {
+                Log.d(TAG, "Feed '" + request.getSource() + "' not modified since last update, Download canceled");
+                onCancelled();
+                return;
+            }
+
             if (!response.isSuccessful() || response.body() == null) {
                 final DownloadError error;
                 final String details;
diff --git a/core/src/main/java/de/danoeh/antennapod/core/storage/DBTasks.java b/core/src/main/java/de/danoeh/antennapod/core/storage/DBTasks.java
index e73f9599d..e0e370b0d 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/storage/DBTasks.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/storage/DBTasks.java
@@ -298,7 +298,8 @@ public final class DBTasks {
     }
 
     /**
-     * Updates a specific Feed.
+     * Refresh a specific Feed. The refresh may get canceled if the feed does not seem to be modified
+     * and the last update was only few days ago.
      *
      * @param context Used for requesting the download.
      * @param feed    The Feed object.
@@ -311,9 +312,9 @@ public final class DBTasks {
     private static void refreshFeed(Context context, Feed feed, boolean loadAllPages) throws DownloadRequestException {
         Feed f;
         if (feed.getPreferences() == null) {
-            f = new Feed(feed.getDownload_url(), new Date(), feed.getTitle());
+            f = new Feed(feed.getDownload_url(), feed.getLastUpdate(), feed.getTitle());
         } else {
-            f = new Feed(feed.getDownload_url(), new Date(), feed.getTitle(),
+            f = new Feed(feed.getDownload_url(), feed.getLastUpdate(), feed.getTitle(),
                     feed.getPreferences().getUsername(), feed.getPreferences().getPassword());
         }
         f.setId(feed.getId());
diff --git a/core/src/main/java/de/danoeh/antennapod/core/storage/DownloadRequester.java b/core/src/main/java/de/danoeh/antennapod/core/storage/DownloadRequester.java
index d0cdad649..ff8d11cb4 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/storage/DownloadRequester.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/storage/DownloadRequester.java
@@ -163,11 +163,19 @@ public class DownloadRequester {
         return true;
     }
 
+    /**
+     * Downloads a feed
+     *
+     * @param context The application's environment.
+     * @param feed Feed to download
+     * @param loadAllPages Set to true to download all pages
+     */
     public synchronized void downloadFeed(Context context, Feed feed, boolean loadAllPages)
             throws DownloadRequestException {
         if (feedFileValid(feed)) {
             String username = (feed.getPreferences() != null) ? feed.getPreferences().getUsername() : null;
             String password = (feed.getPreferences() != null) ? feed.getPreferences().getPassword() : null;
+            long ifModifiedSince = feed.getLastUpdate().getTime();
 
             Bundle args = new Bundle();
             args.putInt(REQUEST_ARG_PAGE_NR, feed.getPageNr());