Return an optional episode instead of null.

diff --git a/src/main/java/net/pterodactylus/rhynodge/filters/EpisodeFilter.java b/src/main/java/net/pterodactylus/rhynodge/filters/EpisodeFilter.java
index 06e88e1..9318d84 100644 (file)
--- a/src/main/java/net/pterodactylus/rhynodge/filters/EpisodeFilter.java
+++ b/src/main/java/net/pterodactylus/rhynodge/filters/EpisodeFilter.java
@@ -17,6 +17,7 @@
 
 package net.pterodactylus.rhynodge.filters;
 
+import static com.google.common.base.Optional.absent;
 import static com.google.common.base.Preconditions.checkState;
 import static java.util.Arrays.asList;
 
@@ -34,6 +35,8 @@ import net.pterodactylus.rhynodge.states.FailedState;
 import net.pterodactylus.rhynodge.states.TorrentState;
 import net.pterodactylus.rhynodge.states.TorrentState.TorrentFile;
 
+import com.google.common.base.Optional;
+
 /**
  * {@link Filter} implementation that extracts {@link Episode} information from
  * the {@link TorrentFile}s contained in a {@link TorrentState}.
@@ -62,15 +65,14 @@ public class EpisodeFilter implements Filter {
                TorrentState torrentState = (TorrentState) state;
                Map<Episode, Episode> episodes = new HashMap<Episode, Episode>();
                for (TorrentFile torrentFile : torrentState) {
-                       Episode episode = extractEpisode(torrentFile);
-                       if (episode == null) {
+                       Optional<Episode> episode = extractEpisode(torrentFile);
+                       if (!episode.isPresent()) {
                                continue;
                        }
-                       if (!episodes.containsKey(episode)) {
-                               episodes.put(episode, episode);
+                       if (!episodes.containsKey(episode.get())) {
+                               episodes.put(episode.get(), episode.get());
                        }
-                       episode = episodes.get(episode);
-                       episode.addTorrentFile(torrentFile);
+                       episodes.get(episode.get()).addTorrentFile(torrentFile);
                }
 
                return new EpisodeState(episodes.values());
@@ -84,11 +86,11 @@ public class EpisodeFilter implements Filter {
         * Extracts episode information from the given torrent file.
         *
         * @param torrentFile
-        *            The torrent file to extract the episode information from
-        * @return The extracted episode information, or {@code null} if no episode
-        *         information could be found
+        *              The torrent file to extract the episode information from
+        * @return The extracted episode information, or {@link Optional#absent()} if
+        *         no episode information could be found
         */
-       private static Episode extractEpisode(TorrentFile torrentFile) {
+       private static Optional<Episode> extractEpisode(TorrentFile torrentFile) {
                for (Pattern episodePattern : episodePatterns) {
                        Matcher matcher = episodePattern.matcher(torrentFile.name());
                        if (!matcher.find() || matcher.groupCount() < 2) {
@@ -98,9 +100,9 @@ public class EpisodeFilter implements Filter {
                        String episodeString = matcher.group(2);
                        int season = Integer.valueOf(seasonString);
                        int episode = Integer.valueOf(episodeString);
-                       return new Episode(season, episode);
+                       return Optional.of(new Episode(season, episode));
                }
-               return null;
+               return absent();
        }
 
 }