[YouTube] Detect when a stream is deleted or doesn't exist

Added a test case as well.

Author: mauriciocolli

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

@@ -11,6 +11,7 @@
 import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.downloader.Downloader;
+import org.schabi.newpipe.extractor.exceptions.ContentNotAvailableException;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.exceptions.ReCaptchaException;
@@ -32,6 +33,7 @@
 import org.schabi.newpipe.extractor.stream.StreamType;
 import org.schabi.newpipe.extractor.stream.SubtitlesStream;
 import org.schabi.newpipe.extractor.stream.VideoStream;
+import org.schabi.newpipe.extractor.utils.JsonUtils;
 import org.schabi.newpipe.extractor.utils.Parser;
 import org.schabi.newpipe.extractor.utils.Utils;
 
@@ -619,6 +621,13 @@ public void onFetchPage(@Nonnull Downloader downloader) throws IOException, Extr
 
         playerResponse = getPlayerResponse();
 
+        final JsonObject playabilityStatus = playerResponse.getObject("playabilityStatus", JsonUtils.DEFAULT_EMPTY);
+        final String status = playabilityStatus.getString("status");
+        if (status != null && status.toLowerCase().equals("error")) {
+            final String reason = playabilityStatus.getString("reason");
+            throw new ContentNotAvailableException("Got error: \"" + reason + "\"");
+        }
+
         if (decryptionCode.isEmpty()) {
             decryptionCode = loadDecryptionCode(playerUrl);
         }

extractor/src/main/java/org/schabi/newpipe/extractor/utils/JsonUtils.java

@@ -11,6 +11,7 @@
 import java.util.List;
 
 public class JsonUtils {
+    public static final JsonObject DEFAULT_EMPTY = new JsonObject();
 
     private JsonUtils() {
     }

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/stream/YoutubeStreamExtractorDefaultTest.java

@@ -7,6 +7,7 @@
 import org.schabi.newpipe.extractor.ExtractorAsserts;
 import org.schabi.newpipe.extractor.MediaFormat;
 import org.schabi.newpipe.extractor.NewPipe;
+import org.schabi.newpipe.extractor.exceptions.ContentNotAvailableException;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeStreamExtractor;
@@ -56,6 +57,27 @@
  */
 public class YoutubeStreamExtractorDefaultTest {
 
+    public static class NotAvailable {
+        @BeforeClass
+        public static void setUp() {
+            NewPipe.init(DownloaderTestImpl.getInstance());
+        }
+
+        @Test(expected = ContentNotAvailableException.class)
+        public void nonExistentFetch() throws Exception {
+            final StreamExtractor extractor =
+                    YouTube.getStreamExtractor("https://www.youtube.com/watch?v=don-t-exist");
+            extractor.fetchPage();
+        }
+
+        @Test(expected = ParsingException.class)
+        public void invalidId() throws Exception {
+            final StreamExtractor extractor =
+                    YouTube.getStreamExtractor("https://www.youtube.com/watch?v=INVALID_ID_INVALID_ID");
+            extractor.fetchPage();
+        }
+    }
+
     /**
      * Test for {@link StreamExtractor}
      */