Fix bugs and present some in the future

build.gradle

@@ -13,7 +13,7 @@ dependencies {
     implementation 'com.grack:nanojson:1.1'
     implementation 'org.jsoup:jsoup:1.9.2'
     implementation 'org.mozilla:rhino:1.7.7.1'
-
+    implementation 'com.github.spotbugs:spotbugs:3.1.0'
     testImplementation 'junit:junit:4.12'
 }
 

src/main/java/org/schabi/newpipe/extractor/Extractor.java

@@ -3,6 +3,8 @@ package org.schabi.newpipe.extractor;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import java.io.IOException;
 
 public abstract class Extractor {
@@ -29,6 +31,7 @@ public abstract class Extractor {
      * <p>
      * Is lazily-cleaned by calling {@link #getCleanUrl()}
      */
+    @Nullable
     private String cleanUrl;
 
     public Extractor(StreamingService service, String url) throws ExtractionException {
@@ -41,6 +44,7 @@ public abstract class Extractor {
     /**
      * @return a {@link UrlIdHandler} of the current extractor type (e.g. a ChannelExtractor should return a channel url handler).
      */
+    @Nonnull
     protected abstract UrlIdHandler getUrlIdHandler() throws ParsingException;
 
     /**
@@ -48,9 +52,18 @@ public abstract class Extractor {
      */
     public abstract void fetchPage() throws IOException, ExtractionException;
 
+    @Nonnull
     public abstract String getId() throws ParsingException;
+
+    /**
+     * Get the name
+     * @return the name
+     * @throws ParsingException if the name cannot be extracted
+     */
+    @Nonnull
     public abstract String getName() throws ParsingException;
 
+    @Nonnull
     public String getOriginalUrl() {
         return originalUrl;
     }
@@ -59,6 +72,7 @@ public abstract class Extractor {
      * Get a clean url and as a fallback the original url.
      * @return the clean url or the original url
      */
+    @Nonnull
     public String getCleanUrl() {
         if (cleanUrl != null && !cleanUrl.isEmpty()) return cleanUrl;
 
@@ -72,6 +86,7 @@ public abstract class Extractor {
         return cleanUrl;
     }
 
+    @Nonnull
     public StreamingService getService() {
         return service;
     }

src/main/java/org/schabi/newpipe/extractor/channel/ChannelExtractor.java

@@ -6,6 +6,7 @@ import org.schabi.newpipe.extractor.UrlIdHandler;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 
 /*
@@ -34,6 +35,7 @@ public abstract class ChannelExtractor extends ListExtractor {
         super(service, url, nextStreamsUrl);
     }
 
+    @Nonnull
     @Override
     protected UrlIdHandler getUrlIdHandler() throws ParsingException {
         return getService().getChannelUrlIdHandler();

src/main/java/org/schabi/newpipe/extractor/channel/ChannelInfo.java

@@ -7,11 +7,9 @@ import org.schabi.newpipe.extractor.ServiceList;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
-import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
 import org.schabi.newpipe.extractor.utils.ExtractorHelper;
 
 import java.io.IOException;
-import java.util.ArrayList;
 
 /*
  * Created by Christian Schabesberger on 31.07.16.

src/main/java/org/schabi/newpipe/extractor/kiosk/KioskExtractor.java

@@ -25,6 +25,7 @@ import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 
 public abstract class KioskExtractor extends ListExtractor {
@@ -51,6 +52,7 @@ public abstract class KioskExtractor extends ListExtractor {
     }
 
 
+    @Nonnull
     @Override
     public String getId() throws ParsingException {
         return id;
@@ -64,6 +66,7 @@ public abstract class KioskExtractor extends ListExtractor {
      * @return the tranlsated version of id
      * @throws ParsingException
      */
+    @Nonnull
     @Override
     public abstract String getName() throws ParsingException;
 

src/main/java/org/schabi/newpipe/extractor/kiosk/KioskList.java

@@ -1,16 +1,13 @@
 package org.schabi.newpipe.extractor.kiosk;
 
 import org.schabi.newpipe.extractor.NewPipe;
-import org.schabi.newpipe.extractor.ServiceList;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.UrlIdHandler;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 
-import java.io.IOError;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Random;
 import java.util.Set;
 
 public  class KioskList {

src/main/java/org/schabi/newpipe/extractor/playlist/PlaylistExtractor.java

@@ -6,6 +6,7 @@ import org.schabi.newpipe.extractor.UrlIdHandler;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 
 public abstract class PlaylistExtractor extends ListExtractor {
@@ -14,6 +15,7 @@ public abstract class PlaylistExtractor extends ListExtractor {
         super(service, url, nextStreamsUrl);
     }
 
+    @Nonnull
     @Override
     protected UrlIdHandler getUrlIdHandler() throws ParsingException {
         return getService().getPlaylistUrlIdHandler();

src/main/java/org/schabi/newpipe/extractor/playlist/PlaylistInfo.java

@@ -4,7 +4,6 @@ import org.schabi.newpipe.extractor.*;
 import org.schabi.newpipe.extractor.ListExtractor.NextItemsResult;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
-import org.schabi.newpipe.extractor.utils.ExtractorHelper;
 
 import java.io.IOException;
 

src/main/java/org/schabi/newpipe/extractor/search/SearchResult.java

@@ -3,9 +3,9 @@ package org.schabi.newpipe.extractor.search;
 import org.schabi.newpipe.extractor.InfoItem;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 
@@ -32,7 +32,9 @@ import java.util.List;
 public class SearchResult {
     private final int serviceId;
     public final String suggestion;
+    @Nonnull
     public final List<InfoItem> resultList;
+    @Nonnull
     public final List<Throwable> errors;
 
     public SearchResult(int serviceId, String suggestion, List<InfoItem> results, List<Throwable> errors) {
@@ -66,10 +68,12 @@ public class SearchResult {
     }
 
 
+    @Nonnull
     public List<InfoItem> getResults() {
         return Collections.unmodifiableList(resultList);
     }
 
+    @Nonnull
     public List<Throwable> getErrors() {
         return errors;
     }

src/main/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudChannelExtractor.java

@@ -11,6 +11,7 @@ import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 
 @SuppressWarnings("WeakerAccess")
@@ -38,16 +39,19 @@ public class SoundcloudChannelExtractor extends ChannelExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getCleanUrl() {
         return user.isString("permalink_url") ? user.getString("permalink_url") : getOriginalUrl();
     }
 
+    @Nonnull
     @Override
     public String getId() {
         return userId;
     }
 
+    @Nonnull
     @Override
     public String getName() {
         return user.getString("username");

src/main/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudChartsExtractor.java

@@ -11,6 +11,8 @@ import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.kiosk.KioskExtractor;
 import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
 
+import javax.annotation.Nonnull;
+
 public class SoundcloudChartsExtractor extends KioskExtractor {
 	private String url;
 
@@ -24,11 +26,13 @@ public class SoundcloudChartsExtractor extends KioskExtractor {
     public void fetchPage() {
     }
 
+    @Nonnull
     @Override
     public String getName() throws ParsingException {
         return "< Implement me (♥_♥) >";
     }
 
+    @Nonnull
     @Override
     public UrlIdHandler getUrlIdHandler() {
         return new SoundcloudChartsUrlIdHandler();

src/main/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudPlaylistExtractor.java

@@ -11,6 +11,7 @@ import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.playlist.PlaylistExtractor;
 import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 
 @SuppressWarnings("WeakerAccess")
@@ -39,16 +40,19 @@ public class SoundcloudPlaylistExtractor extends PlaylistExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getCleanUrl() {
         return playlist.isString("permalink_url") ? playlist.getString("permalink_url") : getOriginalUrl();
     }
 
+    @Nonnull
     @Override
     public String getId() {
         return playlistId;
     }
 
+    @Nonnull
     @Override
     public String getName() {
         return playlist.getString("title");

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

@@ -11,6 +11,7 @@ import org.schabi.newpipe.extractor.exceptions.ReCaptchaException;
 import org.schabi.newpipe.extractor.stream.*;
 import org.schabi.newpipe.extractor.utils.Parser;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.util.*;
 
@@ -19,6 +20,7 @@ public class SoundcloudStreamExtractor extends StreamExtractor {
 
     public SoundcloudStreamExtractor(StreamingService service, String url) throws IOException, ExtractionException {
         super(service, url);
+        fetchPage();
     }
 
     @Override
@@ -31,31 +33,37 @@ public class SoundcloudStreamExtractor extends StreamExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getCleanUrl() {
         return track.isString("permalink_url") ? track.getString("permalink_url") : getOriginalUrl();
     }
 
+    @Nonnull
     @Override
     public String getId() {
         return track.getInt("id") + "";
     }
 
+    @Nonnull
     @Override
     public String getName() {
         return track.getString("title");
     }
 
+    @Nonnull
     @Override
     public String getUploadDate() throws ParsingException {
         return SoundcloudParsingHelper.toDateString(track.getString("created_at"));
     }
 
+    @Nonnull
     @Override
     public String getThumbnailUrl() {
         return track.getString("artwork_url", "");
     }
 
+    @Nonnull
     @Override
     public String getDescription() {
         return track.getString("description");
@@ -91,16 +99,19 @@ public class SoundcloudStreamExtractor extends StreamExtractor {
         return -1;
     }
 
+    @Nonnull
     @Override
     public String getUploaderUrl() {
         return track.getObject("user").getString("permalink_url", "");
     }
 
+    @Nonnull
     @Override
     public String getUploaderName() {
         return track.getObject("user").getString("username", "");
     }
 
+    @Nonnull
     @Override
     public String getUploaderAvatarUrl() {
         return track.getObject("user", new JsonObject()).getString("avatar_url", "");

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

@@ -18,6 +18,7 @@ import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
 import org.schabi.newpipe.extractor.utils.Parser;
 import org.schabi.newpipe.extractor.utils.Utils;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 
 /*
@@ -79,6 +80,7 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
         return true;
     }
 
+    @Nonnull
     @Override
     public String getCleanUrl() {
         try {
@@ -88,6 +90,7 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getId() throws ParsingException {
         try {
@@ -100,6 +103,7 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getName() throws ParsingException {
         try {

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

@@ -19,6 +19,7 @@ import org.schabi.newpipe.extractor.stream.StreamType;
 import org.schabi.newpipe.extractor.utils.Parser;
 import org.schabi.newpipe.extractor.utils.Utils;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 
 @SuppressWarnings("WeakerAccess")
@@ -45,6 +46,7 @@ public class YoutubePlaylistExtractor extends PlaylistExtractor {
         nextStreamsAjax = null;
     }
 
+    @Nonnull
     @Override
     public String getId() throws ParsingException {
         try {
@@ -54,6 +56,7 @@ public class YoutubePlaylistExtractor extends PlaylistExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getName() throws ParsingException {
         try {

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

@@ -22,6 +22,8 @@ import org.schabi.newpipe.extractor.stream.*;
 import org.schabi.newpipe.extractor.utils.Parser;
 import org.schabi.newpipe.extractor.utils.Utils;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import java.io.IOException;
 import java.util.*;
 import java.util.regex.Matcher;
@@ -75,19 +77,23 @@ public class YoutubeStreamExtractor extends StreamExtractor {
     /*//////////////////////////////////////////////////////////////////////////*/
 
     private Document doc;
+    @Nullable
     private JsonObject playerArgs;
-    private Map<String, String> videoInfoPage;
+    @Nonnull
+    private final Map<String, String> videoInfoPage = new HashMap<>();
 
     private boolean isAgeRestricted;
 
     public YoutubeStreamExtractor(StreamingService service, String url) throws IOException, ExtractionException {
         super(service, url);
+        fetchPage();
     }
 
     /*//////////////////////////////////////////////////////////////////////////
     // Impl
     //////////////////////////////////////////////////////////////////////////*/
 
+    @Nonnull
     @Override
     public String getId() throws ParsingException {
         try {
@@ -97,28 +103,25 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getName() throws ParsingException {
-        try {
+        String name = getStringFromMetaData("title");
-            return playerArgs.getString("title");
+        if(name == null) {
-        } catch (Exception ignored) {
-            // Try other method...
-        }
-
-        try {
-            return videoInfoPage.get("title");
-        } catch (Exception ignored) {
-            // Try other method...
-        }
-
-        try {
             // Fallback to HTML method
-            return doc.select("meta[name=title]").attr(CONTENT);
+            try {
+                name = doc.select("meta[name=title]").attr(CONTENT);
             } catch (Exception e) {
                 throw new ParsingException("Could not get the title", e);
             }
         }
+        if(name == null || name.isEmpty()) {
+            throw new ParsingException("Could not get the title");
+        }
+        return name;
+    }
 
+    @Nonnull
     @Override
     public String getUploadDate() throws ParsingException {
         try {
@@ -128,6 +131,7 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getThumbnailUrl() throws ParsingException {
         // Try to get high resolution thumbnail first, if it fails, use low res from the player instead
@@ -138,7 +142,7 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         }
 
         try {
-            if (playerArgs.isString("thumbnail_url")) return playerArgs.getString("thumbnail_url");
+            if (playerArgs != null && playerArgs.isString("thumbnail_url")) return playerArgs.getString("thumbnail_url");
         } catch (Exception ignored) {
             // Try other method...
         }
@@ -150,6 +154,7 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getDescription() throws ParsingException {
         try {
@@ -174,23 +179,27 @@ public class YoutubeStreamExtractor extends StreamExtractor {
 
     @Override
     public long getLength() throws ParsingException {
+        if(playerArgs != null) {
             try {
                 long returnValue = Long.parseLong(playerArgs.get("length_seconds") + "");
                 if (returnValue >= 0) return returnValue;
             } catch (Exception ignored) {
                 // Try other method...
             }
+        }
 
+        String lengthString = videoInfoPage.get("length_seconds");
         try {
-            return Long.parseLong(videoInfoPage.get("length_seconds"));
+            return Long.parseLong(lengthString);
         } catch (Exception ignored) {
             // Try other method...
         }
 
+        // TODO: 25.11.17 Implement a way to get the length for age restricted videos #44
         try {
             // Fallback to HTML method
-            return Long.parseLong(doc.select("div[class~=\"ytp-progress-bar\"][role=\"slider\"]")
+            return Long.parseLong(doc.select("div[class~=\"ytp-progress-bar\"][role=\"slider\"]").first()
-                    .first().attr("aria-valuemax"));
+                    .attr("aria-valuemax"));
         } catch (Exception e) {
             throw new ParsingException("Could not get video length", e);
         }
@@ -253,6 +262,7 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         }
     }
 
+    @Nonnull
     @Override
     public String getUploaderUrl() throws ParsingException {
         try {
@@ -263,28 +273,41 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         }
     }
 
+
+    @Nullable
+    private String getStringFromMetaData(String field) {
+        String value = null;
+        if(playerArgs != null) {
+            // This can not fail
+            value = playerArgs.getString(field);
+        }
+        if(value == null) {
+            // This can not fail too
+            value = videoInfoPage.get(field);
+        }
+        return value;
+    }
+
+    @Nonnull
     @Override
     public String getUploaderName() throws ParsingException {
-        try {
+        String name = getStringFromMetaData("author");
-            return playerArgs.getString("author");
-        } catch (Exception ignored) {
-            // Try other method...
-        }
-
-        try {
-            return videoInfoPage.get("author");
-        } catch (Exception ignored) {
-            // Try other method...
-        }
 
+        if(name == null) {
             try {
                 // Fallback to HTML method
-            return doc.select("div.yt-user-info").first().text();
+                name = doc.select("div.yt-user-info").first().text();
             } catch (Exception e) {
                 throw new ParsingException("Could not get uploader name", e);
             }
         }
+        if(name == null || name.isEmpty()) {
+            throw new ParsingException("Could not get uploader name");
+        }
+        return name;
+    }
 
+    @Nonnull
     @Override
     public String getUploaderAvatarUrl() throws ParsingException {
         try {
@@ -300,9 +323,9 @@ public class YoutubeStreamExtractor extends StreamExtractor {
     public String getDashMpdUrl() throws ParsingException {
         try {
             String dashManifestUrl;
-            if (videoInfoPage != null && videoInfoPage.containsKey("dashmpd")) {
+            if (videoInfoPage.containsKey("dashmpd")) {
                 dashManifestUrl = videoInfoPage.get("dashmpd");
-            } else if (playerArgs.isString("dashmpd")) {
+            } else if (playerArgs != null && playerArgs.isString("dashmpd")) {
                 dashManifestUrl = playerArgs.getString("dashmpd", "");
             } else {
                 return "";
@@ -521,7 +544,7 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         // Check if the video is age restricted
         if (pageContent.contains("<meta property=\"og:restrictions:age")) {
             String infoPageResponse = dl.download(String.format(GET_VIDEO_INFO_URL, getId()));
-            videoInfoPage = Parser.compatParseMap(infoPageResponse);
+            videoInfoPage.putAll(Parser.compatParseMap(infoPageResponse));
             playerUrl = getPlayerUrlFromRestrictedVideo();
             isAgeRestricted = true;
         } else {
@@ -694,7 +717,7 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         String encodedUrlMap = "";
         if (playerArgs != null && playerArgs.isString(encodedUrlMapKey)) {
             encodedUrlMap = playerArgs.getString(encodedUrlMapKey, "");
-        } else if (videoInfoPage != null && videoInfoPage.containsKey(encodedUrlMapKey)) {
+        } else if (videoInfoPage.containsKey(encodedUrlMapKey)) {
             encodedUrlMap = videoInfoPage.get(encodedUrlMapKey);
         }
 

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

@@ -29,6 +29,7 @@ import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.kiosk.KioskExtractor;
 import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 
 public class YoutubeTrendingExtractor extends KioskExtractor {
@@ -54,6 +55,7 @@ public class YoutubeTrendingExtractor extends KioskExtractor {
         doc = Jsoup.parse(pageContent, url);
     }
 
+    @Nonnull
     @Override
     public UrlIdHandler getUrlIdHandler() {
         return new YoutubeTrendingUrlIdHandler();
@@ -64,6 +66,7 @@ public class YoutubeTrendingExtractor extends KioskExtractor {
         return null;
     }
 
+    @Nonnull
     @Override
     public String getName() throws ParsingException {
         try {

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

@@ -30,6 +30,7 @@ import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.exceptions.ReCaptchaException;
 import org.schabi.newpipe.extractor.utils.Parser;
 
+import javax.annotation.Nonnull;
 import java.io.IOException;
 import java.util.List;
 
@@ -40,16 +41,19 @@ public abstract class StreamExtractor extends Extractor {
 
     public StreamExtractor(StreamingService service, String url) throws IOException, ExtractionException {
         super(service, url);
-        fetchPage();
     }
 
+    @Nonnull
     @Override
     protected UrlIdHandler getUrlIdHandler() throws ParsingException {
         return getService().getStreamUrlIdHandler();
     }
 
+    @Nonnull
     public abstract String getUploadDate() throws ParsingException;
+    @Nonnull
     public abstract String getThumbnailUrl() throws ParsingException;
+    @Nonnull
     public abstract String getDescription() throws ParsingException;
     public abstract int getAgeLimit() throws ParsingException;
 
@@ -104,10 +108,18 @@ public abstract class StreamExtractor extends Extractor {
     public abstract long getLikeCount() throws ParsingException;
     public abstract long getDislikeCount() throws ParsingException;
 
+    @Nonnull
     public abstract String getUploaderUrl() throws ParsingException;
+    @Nonnull
     public abstract String getUploaderName() throws ParsingException;
+    @Nonnull
     public abstract String getUploaderAvatarUrl() throws ParsingException;
 
+    /**
+     * Get the dash mpd url
+     * @return the url as a string or an empty string
+     * @throws ParsingException if an error occurs while reading
+     */
     public abstract String getDashMpdUrl() throws ParsingException;
     public abstract List<AudioStream> getAudioStreams() throws IOException, ExtractionException;
     public abstract List<VideoStream> getVideoStreams() throws IOException, ExtractionException;

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

@@ -7,7 +7,6 @@ import org.schabi.newpipe.extractor.utils.DashMpdParser;
 import org.schabi.newpipe.extractor.utils.ExtractorHelper;
 
 import java.io.IOException;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 

src/test/java/org/schabi/newpipe/Downloader.java

@@ -89,10 +89,8 @@ public class Downloader implements org.schabi.newpipe.extractor.Downloader {
     public String download(String siteUrl, Map<String, String> customProperties) throws IOException, ReCaptchaException {
         URL url = new URL(siteUrl);
         HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
-        Iterator it = customProperties.entrySet().iterator();
+        for (Map.Entry<String, String> pair: customProperties.entrySet()) {
-        while (it.hasNext()) {
+            con.setRequestProperty(pair.getKey(), pair.getValue());
-            Map.Entry pair = (Map.Entry) it.next();
-            con.setRequestProperty((String) pair.getKey(), (String) pair.getValue());
         }
         return dl(con);
     }

src/test/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudChartsExtractorTest.java

@@ -10,13 +10,10 @@ import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
 import org.schabi.newpipe.Downloader;
-import org.schabi.newpipe.extractor.InfoItemCollector;
 import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.kiosk.KioskExtractor;
 import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
 
-import java.util.List;
-
 /**
  * Test for {@link SoundcloudChartsUrlIdHandler}
  */

src/test/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudSearchEngineAllTest.java

@@ -9,6 +9,7 @@ import org.schabi.newpipe.extractor.search.SearchEngine;
 import org.schabi.newpipe.extractor.search.SearchResult;
 
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.schabi.newpipe.extractor.ServiceList.SoundCloud;
 
@@ -36,8 +37,9 @@ public class SoundcloudSearchEngineAllTest {
 
     @Test
     public void testResultErrors() {
+        assertNotNull(result.errors);
         if (!result.errors.isEmpty()) for (Throwable error : result.errors) error.printStackTrace();
-        assertTrue(result.errors == null || result.errors.isEmpty());
+        assertTrue(result.errors.isEmpty());
     }
 
     @Ignore

src/test/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudSearchEngineChannelTest.java

@@ -43,8 +43,9 @@ public class SoundcloudSearchEngineChannelTest {
 
     @Test
     public void testResultErrors() {
+        assertNotNull(result.errors);
         if (!result.errors.isEmpty()) for (Throwable error : result.errors) error.printStackTrace();
-        assertTrue(result.errors == null || result.errors.isEmpty());
+        assertTrue(result.errors.isEmpty());
     }
 
     @Ignore

src/test/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudSearchEnginePlaylistTest.java

@@ -63,8 +63,9 @@ public class SoundcloudSearchEnginePlaylistTest {
 
     @Test
     public void testResultErrors() {
+        assertNotNull(result.errors);
         if (!result.errors.isEmpty()) for (Throwable error : result.errors) error.printStackTrace();
-        assertTrue(result.errors == null || result.errors.isEmpty());
+        assertTrue(result.errors.isEmpty());
     }
 
     @Ignore

src/test/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudSearchEngineStreamTest.java

@@ -43,8 +43,9 @@ public class SoundcloudSearchEngineStreamTest {
 
     @Test
     public void testResultErrors() {
+        assertNotNull(result.errors);
         if (!result.errors.isEmpty()) for (Throwable error : result.errors) error.printStackTrace();
-        assertTrue(result.errors == null || result.errors.isEmpty());
+        assertTrue(result.errors.isEmpty());
     }
 
     @Ignore

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeSearchEngineAllTest.java

@@ -1,6 +1,5 @@
 package org.schabi.newpipe.extractor.services.youtube;
 
-import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -11,7 +10,6 @@ import org.schabi.newpipe.extractor.search.SearchResult;
 
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-import static org.schabi.newpipe.extractor.ServiceList.YouTube;
 
 /*
  * Created by Christian Schabesberger on 29.12.15.

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeSearchEngineChannelTest.java

@@ -64,8 +64,9 @@ public class YoutubeSearchEngineChannelTest {
 
     @Test
     public void testResultErrors() {
+        assertNotNull(result.errors);
         if (!result.errors.isEmpty()) for (Throwable error : result.errors) error.printStackTrace();
-        assertTrue(result.errors == null || result.errors.isEmpty());
+        assertTrue(result.errors.isEmpty());
     }
 
     @Ignore

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeSearchEnginePlaylistTest.java

@@ -64,8 +64,9 @@ public class YoutubeSearchEnginePlaylistTest {
 
     @Test
     public void testResultErrors() {
+        assertNotNull(result.errors);
         if (!result.errors.isEmpty()) for (Throwable error : result.errors) error.printStackTrace();
-        assertTrue(result.errors == null || result.errors.isEmpty());
+        assertTrue(result.errors.isEmpty());
     }
 
     @Ignore

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeSearchEngineStreamTest.java

@@ -64,8 +64,9 @@ public class YoutubeSearchEngineStreamTest {
 
     @Test
     public void testResultErrors() {
+        assertNotNull(result.errors);
         if (!result.errors.isEmpty()) for (Throwable error : result.errors) error.printStackTrace();
-        assertTrue(result.errors == null || result.errors.isEmpty());
+        assertTrue(result.errors.isEmpty());
     }
 
     @Ignore

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeServiceTest.java

@@ -26,7 +26,6 @@ import org.schabi.newpipe.Downloader;
 import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.kiosk.KioskList;
-import org.schabi.newpipe.extractor.search.SearchEngine;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;

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

@@ -67,14 +67,17 @@ public class YoutubeStreamExtractorDefaultTest {
 
     @Test
     public void testGetDescription() throws ParsingException {
-        assertTrue(extractor.getDescription() != null);
+        assertNotNull(extractor.getDescription());
+        assertFalse(extractor.getDescription().isEmpty());
     }
 
     @Test
     public void testGetUploaderName() throws ParsingException {
-        assertTrue(!extractor.getUploaderName().isEmpty());
+        assertNotNull(extractor.getUploaderName());
+        assertFalse(extractor.getUploaderName().isEmpty());
     }
 
+
     @Test
     public void testGetLength() throws ParsingException {
         assertTrue(extractor.getLength() > 0);

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeStreamExtractorRestrictedTest.java

@@ -2,6 +2,7 @@ package org.schabi.newpipe.extractor.services.youtube;
 
 import com.grack.nanojson.JsonParserException;
 import org.junit.Before;
+import org.junit.Ignore;
 import org.junit.Test;
 import org.schabi.newpipe.Downloader;
 import org.schabi.newpipe.extractor.NewPipe;
@@ -13,8 +14,7 @@ import org.schabi.newpipe.extractor.stream.VideoStream;
 
 import java.io.IOException;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.*;
-import static org.junit.Assert.assertTrue;
 import static org.schabi.newpipe.extractor.ServiceList.YouTube;
 
 /**
@@ -22,12 +22,12 @@ import static org.schabi.newpipe.extractor.ServiceList.YouTube;
  */
 public class YoutubeStreamExtractorRestrictedTest {
     public static final String HTTPS = "https://";
-    private StreamExtractor extractor;
+    private YoutubeStreamExtractor extractor;
 
     @Before
     public void setUp() throws Exception {
         NewPipe.init(Downloader.getInstance());
-        extractor = YouTube.getService()
+        extractor = (YoutubeStreamExtractor) YouTube.getService()
                 .getStreamExtractor("https://www.youtube.com/watch?v=i6JTvzrpBy0");
     }
 
@@ -48,20 +48,24 @@ public class YoutubeStreamExtractorRestrictedTest {
     }
 
     @Test
-    public void testGetTitle() throws ParsingException {
+    public void testGetName() throws ParsingException {
-        assertTrue(!extractor.getName().isEmpty());
+        assertNotNull("name is null", extractor.getName());
+        assertFalse("name is empty", extractor.getName().isEmpty());
     }
 
     @Test
     public void testGetDescription() throws ParsingException {
-        assertTrue(extractor.getDescription() != null);
+        assertNotNull(extractor.getDescription());
+        assertFalse(extractor.getDescription().isEmpty());
     }
 
     @Test
     public void testGetUploaderName() throws ParsingException {
-        assertTrue(!extractor.getUploaderName().isEmpty());
+        assertNotNull(extractor.getUploaderName());
+        assertFalse(extractor.getUploaderName().isEmpty());
     }
 
+    @Ignore // Currently there is no way get the length from restricted videos
     @Test
     public void testGetLength() throws ParsingException {
         assertTrue(extractor.getLength() > 0);
@@ -89,9 +93,10 @@ public class YoutubeStreamExtractorRestrictedTest {
                 extractor.getUploaderAvatarUrl().contains(HTTPS));
     }
 
+    // FIXME: 25.11.17 Are there no streams or are they not listed?
     @Test
     public void testGetAudioStreams() throws IOException, ExtractionException {
-        // audiostream not always necessary
+        // audio streams are not always necessary
         assertTrue(!extractor.getAudioStreams().isEmpty());
     }
 

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeTrendingExtractorTest.java

@@ -23,7 +23,6 @@ package org.schabi.newpipe.extractor.services.youtube;
 import org.junit.Before;
 import org.junit.Test;
 import org.schabi.newpipe.Downloader;
-import org.schabi.newpipe.extractor.InfoItemCollector;
 import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.kiosk.KioskExtractor;
 import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;