Cleanup

* Removed unused code
* Fixed checkstyle problems
* Added some docs

Author: litetex

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

@@ -31,7 +31,7 @@
 /**
  * A list of supported services.
  */
-// keep unusual names and inner assignments
+@SuppressWarnings("ConstantName") // keep unusual names
 public final class ServiceList {
     private ServiceList() {
         //no instance

extractor/src/main/java/org/schabi/newpipe/extractor/instance/AbstractInstance.java

@@ -9,8 +9,6 @@
 
 public abstract class AbstractInstance implements Instance {
 
-    protected Boolean valid = null;
-
     protected final String url;
     protected String name;
 

extractor/src/main/java/org/schabi/newpipe/extractor/instance/Instance.java

@@ -17,17 +17,12 @@ public interface Instance {
      * The base url of this instance.
      * <br/>
      * Note that the url is returned without trailing slashes.
-     * Use {@link #getUrlWithTrailingSlash()} if you want a trailing slash.
      *
      * @return base url
      */
     @Nonnull
     String getUrl();
 
-    default String getUrlWithTrailingSlash() {
-        return getUrl() + "/";
-    }
-
 
     /**
      * Fetch instance metadata.

extractor/src/main/java/org/schabi/newpipe/extractor/instance/InstanceMetaDataFetchException.java

@@ -1,5 +1,8 @@
 package org.schabi.newpipe.extractor.instance;
 
+/**
+ * Thrown when an {@link Instance} couldn't be validated.
+ */
 public class InstanceMetaDataFetchException extends RuntimeException {
     public InstanceMetaDataFetchException(final String message) {
         super(message);

extractor/src/main/java/org/schabi/newpipe/extractor/services/bandcamp/BandcampService.java

@@ -13,7 +13,6 @@
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.channel.ChannelExtractor;
 import org.schabi.newpipe.extractor.comments.CommentsExtractor;
-import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.kiosk.KioskList;
 import org.schabi.newpipe.extractor.linkhandler.LinkHandler;
 import org.schabi.newpipe.extractor.linkhandler.LinkHandlerFactory;

extractor/src/main/java/org/schabi/newpipe/extractor/services/media_ccc/MediaCCCService.java

@@ -7,7 +7,6 @@
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.channel.ChannelExtractor;
 import org.schabi.newpipe.extractor.comments.CommentsExtractor;
-import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.kiosk.KioskList;
 import org.schabi.newpipe.extractor.linkhandler.LinkHandler;
 import org.schabi.newpipe.extractor.linkhandler.LinkHandlerFactory;

extractor/src/main/java/org/schabi/newpipe/extractor/services/peertube/PeertubeInstance.java

@@ -42,7 +42,7 @@ public void fetchMetadata() {
             this.setName(JsonUtils.getString(json, "instance.name"));
         } catch (final Exception e) {
             throw new InstanceMetaDataFetchException(
-                    "Unable to fetch trending from " + urlToCheck, e);
+                    "Unable to fetch config from " + urlToCheck, e);
         }
     }
 }

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

@@ -2,6 +2,11 @@
 
 import org.schabi.newpipe.extractor.instance.AbstractInstance;
 
+/**
+ * A YouTube-like instance (or proxy)
+ *
+ * @param <S>
+ */
 public abstract class YoutubeLikeInstance<S extends YoutubeLikeStreamingService>
         extends AbstractInstance {
 

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

@@ -33,15 +33,15 @@ protected YoutubeLikeStreamingService(
     }
 
     @Override
-    public abstract StreamExtractor getStreamExtractor(final LinkHandler linkHandler);
+    public abstract StreamExtractor getStreamExtractor(LinkHandler linkHandler);
 
     @Override
-    public abstract ChannelExtractor getChannelExtractor(final ListLinkHandler linkHandler);
+    public abstract ChannelExtractor getChannelExtractor(ListLinkHandler linkHandler);
 
     @Override
-    public abstract PlaylistExtractor getPlaylistExtractor(final ListLinkHandler linkHandler);
+    public abstract PlaylistExtractor getPlaylistExtractor(ListLinkHandler linkHandler);
 
     @Nonnull
     @Override
-    public abstract FeedExtractor getFeedExtractor(final String url) throws ExtractionException;
+    public abstract FeedExtractor getFeedExtractor(String url) throws ExtractionException;
 }

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/invidious/InvidiousInstance.java

@@ -65,7 +65,7 @@ private void checkEndpoint(
             responseCheck.check(response);
         } catch (final Exception e) {
             throw new InstanceMetaDataFetchException(
-                    "Unable to fetch trending from " + urlToCheck, e);
+                    "Unable to fetch from " + urlToCheck, e);
         }
     }
 
@@ -81,6 +81,6 @@ public String getServiceName() {
 
     @FunctionalInterface
     public interface ResponseCheck {
-        void check(final Response r) throws Exception;
+        void check(Response r) throws Exception;
     }
 }