Add some missing finals, nullables and comments

extractor/src/main/java/org/schabi/newpipe/extractor/services/media_ccc/extractors/MediaCCCParsingHelper.java

@@ -12,9 +12,9 @@ public final class MediaCCCParsingHelper {
     private MediaCCCParsingHelper() { }
 
     public static Calendar parseDateFrom(final String textualUploadDate) throws ParsingException {
-        Date date;
+        final Date date;
         try {
-            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
+            final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
             sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
             date = sdf.parse(textualUploadDate);
         } catch (ParseException e) {

extractor/src/main/java/org/schabi/newpipe/extractor/services/media_ccc/extractors/MediaCCCStreamExtractor.java

@@ -30,6 +30,7 @@ import java.util.List;
 import java.util.Locale;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 public class MediaCCCStreamExtractor extends StreamExtractor {
     private JsonObject data;
@@ -217,6 +218,7 @@ public class MediaCCCStreamExtractor extends StreamExtractor {
         return StreamType.VIDEO_STREAM;
     }
 
+    @Nullable
     @Override
     public StreamInfoItemsCollector getRelatedStreams() {
         return null;

extractor/src/main/java/org/schabi/newpipe/extractor/services/peertube/extractors/PeertubeAccountExtractor.java

@@ -96,7 +96,8 @@ public class PeertubeAccountExtractor extends ChannelExtractor {
     }
 
     @Override
-    public InfoItemsPage<StreamInfoItem> getPage(final Page page) throws IOException, ExtractionException {
+    public InfoItemsPage<StreamInfoItem> getPage(final Page page)
+            throws IOException, ExtractionException {
         if (page == null || isNullOrEmpty(page.getUrl())) {
             throw new IllegalArgumentException("Page doesn't contain an URL");
         }
@@ -126,7 +127,8 @@ public class PeertubeAccountExtractor extends ChannelExtractor {
     }
 
     @Override
-    public void onFetchPage(@Nonnull Downloader downloader) throws IOException, ExtractionException {
+    public void onFetchPage(@Nonnull final Downloader downloader)
+            throws IOException, ExtractionException {
         String accountUrl = baseUrl + PeertubeChannelLinkHandlerFactory.API_ENDPOINT;
         if (getId().contains("accounts/")) {
             accountUrl += getId();

extractor/src/main/java/org/schabi/newpipe/extractor/services/peertube/extractors/PeertubeStreamExtractor.java

@@ -38,6 +38,7 @@ import java.util.List;
 import java.util.Locale;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 public class PeertubeStreamExtractor extends StreamExtractor {
     private final String baseUrl;
@@ -113,7 +114,7 @@ public class PeertubeStreamExtractor extends StreamExtractor {
 
     @Override
     public long getTimeStamp() throws ParsingException {
-        long timestamp =
+        final long timestamp =
                 getTimestampSeconds("((#|&|\\?)start=\\d{0,3}h?\\d{0,3}m?\\d{1,3}s?)");
 
         if (timestamp == -2) {
@@ -261,20 +262,25 @@ public class PeertubeStreamExtractor extends StreamExtractor {
         return StreamType.VIDEO_STREAM;
     }
 
+    @Nullable
     @Override
     public StreamInfoItemsCollector getRelatedStreams() throws IOException, ExtractionException {
-        final StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());
         final List<String> tags = getTags();
         final String apiUrl;
-        if (!tags.isEmpty()) {
+        if (tags.isEmpty()) {
-            apiUrl = getRelatedStreamsUrl(tags);
-
-        } else {
             apiUrl = getUploaderUrl() + "/videos?start=0&count=8";
+        } else {
+            apiUrl = getRelatedStreamsUrl(tags);
         }
-        if (!Utils.isBlank(apiUrl)) getStreamsFromApi(collector, apiUrl);
+
+        if (Utils.isBlank(apiUrl)) {
+            return null;
+        } else {
+            final StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());
+            getStreamsFromApi(collector, apiUrl);
             return collector;
         }
+    }
 
     @Nonnull
     @Override

extractor/src/main/java/org/schabi/newpipe/extractor/services/soundcloud/extractors/SoundcloudStreamExtractor.java

@@ -33,6 +33,7 @@ import java.util.List;
 import java.util.Locale;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 import static org.schabi.newpipe.extractor.utils.JsonUtils.EMPTY_STRING;
 import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
@@ -262,6 +263,7 @@ public class SoundcloudStreamExtractor extends StreamExtractor {
         return StreamType.AUDIO_STREAM;
     }
 
+    @Nullable
     @Override
     public StreamInfoItemsCollector getRelatedStreams() throws IOException, ExtractionException {
         final StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeParsingHelper.java

@@ -183,9 +183,9 @@ public class YoutubeParsingHelper {
     }
 
     public static Calendar parseDateFrom(String textualUploadDate) throws ParsingException {
-        Date date;
+        final Date date;
         try {
-            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
+            final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
             sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
             date = sdf.parse(textualUploadDate);
         } catch (ParseException e) {

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/extractors/YoutubeStreamExtractor.java

@@ -576,11 +576,14 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         }
     }
 
+    @Nullable
     @Override
     public StreamInfoItemsCollector getRelatedStreams() throws ExtractionException {
         assertPageFetched();
 
-        if (getAgeLimit() != NO_AGE_LIMIT) return null;
+        if (getAgeLimit() != NO_AGE_LIMIT) {
+            return null;
+        }
 
         try {
             final StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());

extractor/src/main/java/org/schabi/newpipe/extractor/stream/StreamExtractor.java

@@ -321,6 +321,7 @@ public abstract class StreamExtractor extends Extractor {
      * @throws IOException
      * @throws ExtractionException
      */
+    @Nullable
     public abstract StreamInfoItemsCollector getRelatedStreams() throws IOException, ExtractionException;
 
     /**

extractor/src/test/java/org/schabi/newpipe/extractor/services/DefaultStreamExtractorTest.java

@@ -249,6 +249,7 @@ public abstract class DefaultStreamExtractorTest extends DefaultExtractorTest<St
                 assertFalse(stream.getResolution().isEmpty());
 
                 final int formatId = stream.getFormatId();
+                // see MediaFormat: video stream formats range from 0 to 0x100
                 assertTrue("format id does not fit a video stream: " + formatId,
                         0 <= formatId && formatId < 0x100);
             }
@@ -270,6 +271,7 @@ public abstract class DefaultStreamExtractorTest extends DefaultExtractorTest<St
                 assertIsSecureUrl(stream.getUrl());
 
                 final int formatId = stream.getFormatId();
+                // see MediaFormat: video stream formats range from 0x100 to 0x1000
                 assertTrue("format id does not fit an audio stream: " + formatId,
                         0x100 <= formatId && formatId < 0x1000);
             }
@@ -291,6 +293,7 @@ public abstract class DefaultStreamExtractorTest extends DefaultExtractorTest<St
                 assertIsSecureUrl(stream.getUrl());
 
                 final int formatId = stream.getFormatId();
+                // see MediaFormat: video stream formats range from 0x1000 to 0x10000
                 assertTrue("format id does not fit a subtitles stream: " + formatId,
                         0x1000 <= formatId && formatId < 0x10000);
             }