Return an optional instead of throwing an exception.

[sonitus.git] / src / main / java / net / pterodactylus / sonitus / io / OggVorbisIdentifier.java

diff --git a/src/main/java/net/pterodactylus/sonitus/io/OggVorbisIdentifier.java b/src/main/java/net/pterodactylus/sonitus/io/OggVorbisIdentifier.java
index ab732b8..d889b97 100644 (file)
--- a/src/main/java/net/pterodactylus/sonitus/io/OggVorbisIdentifier.java
+++ b/src/main/java/net/pterodactylus/sonitus/io/OggVorbisIdentifier.java
@@ -22,6 +22,7 @@ import java.io.InputStream;
 
 import net.pterodactylus.sonitus.data.Format;
 
+import com.google.common.base.Optional;
 import com.jcraft.jogg.Packet;
 import com.jcraft.jogg.Page;
 import com.jcraft.jogg.StreamState;
@@ -49,10 +50,13 @@ public class OggVorbisIdentifier {
         * Format} describing the stream.
         *
         * @param inputStream
-        * @return
+        *              The input stream to identify as Ogg Vorbis
+        * @return The identified format, or {@link com.google.common.base.Optional#absent()}
+        *         if the stream could not be identified
         * @throws IOException
+        *              if an I/O error occurs
         */
-       public static Format identify(InputStream inputStream) throws IOException {
+       public static Optional<Format> identify(InputStream inputStream) throws IOException {
 
                /* stuff needed to decode Ogg. */
                Packet packet = new Packet();
@@ -79,7 +83,7 @@ public class OggVorbisIdentifier {
                        syncState.wrote(read);
                        switch (syncState.pageout(page)) {
                                case -1:
-                                       throw new IdentifierException("Hole in Ogg data!");
+                                       return Optional.absent();
                                case 1:
                                        if (!streamStateInitialized) {
                                                /* init stream state. */
@@ -90,11 +94,11 @@ public class OggVorbisIdentifier {
                                                streamStateInitialized = true;
                                        }
                                        if (streamState.pagein(page) == -1) {
-                                               throw new IdentifierException("Error parsing Ogg data!");
+                                               return Optional.absent();
                                        }
                                        switch (streamState.packetout(packet)) {
                                                case -1:
-                                                       throw new IdentifierException("Error parsing Ogg data!");
+                                                       return Optional.absent();
                                                case 1:
                                                        info.synthesis_headerin(comment, packet);
                                                        packetsRead++;
@@ -109,7 +113,7 @@ public class OggVorbisIdentifier {
                        buffer = syncState.data;
                }
 
-               return new Format(info.channels, info.rate, "Vorbis");
+               return Optional.of(new Format(info.channels, info.rate, "Vorbis"));
        }
 
 }