Refactor Extractor#getDownloader to be a static shorthand

The downloader is global there is no sense to store reference to it
in every instance of Extractor. So eliminate the field, make
getDownloader shorthand for Newpipe.getDownloader and make it static
to be accesible in static functions of extractors

Author: Yevhen Babiichuk (DustDFG)

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

@@ -29,13 +29,10 @@ public abstract class Extractor {
     private ContentCountry forcedContentCountry = null;
 
     private boolean pageFetched = false;
-    // called like this to prevent checkstyle errors about "hiding a field"
-    private final Downloader downloader;
 
     protected Extractor(final StreamingService service, final LinkHandler linkHandler) {
         this.service = Objects.requireNonNull(service, "service is null");
         this.linkHandler = Objects.requireNonNull(linkHandler, "LinkHandler is null");
-        this.downloader = Objects.requireNonNull(NewPipe.getDownloader(), "downloader is null");
     }
 
     /**
@@ -117,8 +114,8 @@ public int getServiceId() {
         return service.getServiceId();
     }
 
-    public Downloader getDownloader() {
-        return downloader;
+    public static Downloader getDownloader() {
+        return NewPipe.getDownloader();
     }
 
     /*//////////////////////////////////////////////////////////////////////////

extractor/src/main/java/org/schabi/newpipe/extractor/services/bandcamp/extractors/BandcampRadioStreamExtractor.java

@@ -15,7 +15,6 @@
 import org.schabi.newpipe.extractor.Image;
 import org.schabi.newpipe.extractor.Image.ResolutionLevel;
 import org.schabi.newpipe.extractor.MediaFormat;
-import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.exceptions.ContentNotSupportedException;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
@@ -48,7 +47,7 @@ public BandcampRadioStreamExtractor(final StreamingService service,
 
     static JsonObject query(final int id) throws ParsingException {
         try {
-            return JsonParser.object().from(NewPipe.getDownloader()
+            return JsonParser.object().from(getDownloader()
                     .get(BASE_API_URL + "/bcweekly/1/get?id=" + id).responseBody());
         } catch (final IOException | ReCaptchaException | JsonParserException e) {
             throw new ParsingException("could not get show data", e);

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

@@ -7,7 +7,6 @@
 import com.grack.nanojson.JsonParserException;
 
 import org.schabi.newpipe.extractor.Image;
-import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.channel.ChannelExtractor;
 import org.schabi.newpipe.extractor.channel.tabs.ChannelTabs;
@@ -36,7 +35,7 @@ static JsonObject fetchConferenceData(@Nonnull final String conferenceId)
         final String conferenceUrl
                 = MediaCCCConferenceLinkHandlerFactory.CONFERENCE_API_ENDPOINT + conferenceId;
         try {
-            return JsonParser.object().from(NewPipe.getDownloader()
+            return JsonParser.object().from(getDownloader()
                     .get(conferenceUrl).responseBody());
         } catch (final JsonParserException jpe) {
             throw new ExtractionException("Could not parse json returned by URL: " + conferenceUrl);

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

@@ -11,9 +11,7 @@
 import com.grack.nanojson.JsonParserException;
 import org.schabi.newpipe.extractor.Image;
 import org.schabi.newpipe.extractor.MediaFormat;
-import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.StreamingService;
-import org.schabi.newpipe.extractor.downloader.Downloader;
 import org.schabi.newpipe.extractor.downloader.Response;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
@@ -99,9 +97,8 @@ public Description getDescription() throws ParsingException {
         }
         if (text.length() == 250 && text.substring(247).equals("...")) {
             // If description is shortened, get full description
-            final Downloader dl = NewPipe.getDownloader();
             try {
-                final Response response = dl.get(baseUrl
+                final Response response = getDownloader().get(baseUrl
                         + PeertubeStreamLinkHandlerFactory.VIDEO_API_ENDPOINT
                         + getId() + "/description");
                 final JsonObject jsonObject = JsonParser.object().from(response.responseBody());

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

@@ -5,13 +5,11 @@
 import com.grack.nanojson.JsonParser;
 import com.grack.nanojson.JsonParserException;
 
-import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.Page;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.comments.CommentsExtractor;
 import org.schabi.newpipe.extractor.comments.CommentsInfoItem;
 import org.schabi.newpipe.extractor.comments.CommentsInfoItemsCollector;
-import org.schabi.newpipe.extractor.downloader.Downloader;
 import org.schabi.newpipe.extractor.downloader.Response;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
@@ -49,8 +47,7 @@ public InfoItemsPage<CommentsInfoItem> getPage(final Page page) throws Extractio
     @Nonnull
     private InfoItemsPage<CommentsInfoItem> getPage(@Nonnull final String url)
             throws ParsingException, IOException, ReCaptchaException {
-        final Downloader downloader = NewPipe.getDownloader();
-        final Response response = downloader.get(url);
+        final Response response = getDownloader().get(url);
 
         final JsonObject json;
         try {

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

@@ -11,7 +11,6 @@
 import com.grack.nanojson.JsonParserException;
 
 import org.schabi.newpipe.extractor.Image;
-import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.Page;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
@@ -178,7 +177,7 @@ public InfoItemsPage<StreamInfoItem> getPage(final Page page) throws IOException
                 + SoundcloudParsingHelper.clientId() + "&ids=" + String.join(",", currentIds);
 
         final StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());
-        final String response = NewPipe.getDownloader().get(currentPageUrl,
+        final String response = getDownloader().get(currentPageUrl,
                 getExtractorLocalization()).responseBody();
 
         try {

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

@@ -16,7 +16,6 @@
 
 import org.schabi.newpipe.extractor.Image;
 import org.schabi.newpipe.extractor.MediaFormat;
-import org.schabi.newpipe.extractor.NewPipe;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.exceptions.ContentNotAvailableException;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
@@ -189,7 +188,7 @@ private String getTranscodingUrl(final String endpointUrl)
             apiStreamUrl += "&track_authorization=" + trackAuthorization;
         }
 
-        final String response = NewPipe.getDownloader().get(apiStreamUrl).responseBody();
+        final String response = getDownloader().get(apiStreamUrl).responseBody();
         final JsonObject urlObject;
         try {
             urlObject = JsonParser.object().from(response);