Refactor and improvements

build.gradle

@@ -10,5 +10,8 @@ dependencies {
     implementation 'org.mozilla:rhino:1.7.7.1'
 
     testImplementation 'junit:junit:4.12'
+
+    sourceCompatibility = 1.7
+    targetCompatibility = 1.7
 }
 

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

@@ -1,35 +1,73 @@
 package org.schabi.newpipe.extractor;
 
-import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
+import org.schabi.newpipe.extractor.exceptions.ExtractionException;
+import org.schabi.newpipe.extractor.exceptions.ParsingException;
 
-import java.io.Serializable;
+import java.io.IOException;
 
-public abstract class Extractor implements Serializable {
-    private final int serviceId;
-    private final String url;
-    private final UrlIdHandler urlIdHandler;
-    private final StreamInfoItemCollector previewInfoCollector;
+public abstract class Extractor {
+    /**
+     * {@link StreamingService} currently related to this extractor.<br/>
+     * Useful for getting other things from a service (like the url handlers for cleaning/accepting/get id from urls).
+     */
+    private final StreamingService service;
 
-    public Extractor(UrlIdHandler urlIdHandler, int serviceId, String url) {
-        this.urlIdHandler = urlIdHandler;
-        this.serviceId = serviceId;
-        this.url = url;
-        this.previewInfoCollector = new StreamInfoItemCollector(serviceId);
+    /**
+     * Dirty/original url that was passed in the constructor.
+     * <p>
+     * What makes a url "dirty" or not is, for example, the additional parameters
+     * (not important as—in this case—the id):
+     * <pre>
+     *     https://www.youtube.com/watch?v=a9Zf_258aTI<i>&t=4s</i>  →  <i><b>&t=4s</b></i>
+     * </pre>
+     * But as you can imagine, the time parameter is very important when calling, for example, {@link org.schabi.newpipe.extractor.stream.StreamExtractor#getTimeStamp()}.
+     */
+    private final String originalUrl;
+
+    /**
+     * The cleaned url, result of passing the {@link #originalUrl} to the associated urlIdHandler ({@link #getUrlIdHandler()}).
+     * <p>
+     * Is lazily-cleaned by calling {@link #getCleanUrl()}
+     */
+    private String cleanUrl;
+
+    public Extractor(StreamingService service, String url) throws ExtractionException {
+        this.service = service;
+        this.originalUrl = url;
     }
 
-    public String getUrl() {
-        return url;
+    /**
+     * @return a {@link UrlIdHandler} of the current extractor type (e.g. a ChannelExtractor should return a channel url handler).
+     */
+    protected abstract UrlIdHandler getUrlIdHandler() throws ParsingException;
+
+    /**
+     * Fetch the current page.
+     */
+    public abstract void fetchPage() throws IOException, ExtractionException;
+
+    public String getOriginalUrl() {
+        return originalUrl;
     }
 
-    public UrlIdHandler getUrlIdHandler() {
-        return urlIdHandler;
+    public String getCleanUrl() {
+        if (cleanUrl != null && !cleanUrl.isEmpty()) return cleanUrl;
+
+        try {
+            cleanUrl = getUrlIdHandler().cleanUrl(originalUrl);
+        } catch (Exception e) {
+            cleanUrl = null;
+            // Fallback to the original url
+            return originalUrl;
+        }
+        return cleanUrl;
     }
 
-    public int getServiceId() {
-        return serviceId;
+    public StreamingService getService() {
+        return service;
     }
 
-    protected StreamInfoItemCollector getStreamPreviewInfoCollector() {
-        return previewInfoCollector;
+    public int getServiceId() {
+        return service.getServiceId();
     }
 }

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

@@ -1,8 +1,8 @@
 package org.schabi.newpipe.extractor;
 
 import java.io.Serializable;
+import java.util.ArrayList;
 import java.util.List;
-import java.util.Vector;
 
 public abstract class Info implements Serializable {
 
@@ -15,5 +15,5 @@ public abstract class Info implements Serializable {
     public String url;
     public String name;
 
-    public List<Throwable> errors = new Vector<>();
+    public List<Throwable> errors = new ArrayList<>();
 }

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

@@ -2,8 +2,8 @@
 
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 
+import java.util.ArrayList;
 import java.util.List;
-import java.util.Vector;
 
 /*
  * Created by Christian Schabesberger on 12.02.17.
@@ -26,8 +26,8 @@
  */
 
 public abstract class InfoItemCollector {
-    private List<InfoItem> itemList = new Vector<>();
-    private List<Throwable> errors = new Vector<>();
+    private List<InfoItem> itemList = new ArrayList<>();
+    private List<Throwable> errors = new ArrayList<>();
     private int serviceId = -1;
 
     public InfoItemCollector(int serviceId) {
@@ -46,7 +46,7 @@ protected void addFromCollector(InfoItemCollector otherC) throws ExtractionExcep
         if (serviceId != otherC.serviceId) {
             throw new ExtractionException("Service Id does not equal: "
                     + NewPipe.getNameOfService(serviceId)
-                    + " and " + NewPipe.getNameOfService(otherC.serviceId));
+                    + " and " + NewPipe.getNameOfService((otherC.serviceId)));
         }
         errors.addAll(otherC.errors);
         itemList.addAll(otherC.itemList);

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

@@ -4,22 +4,47 @@
 import org.schabi.newpipe.extractor.stream.StreamInfoItemCollector;
 
 import java.io.IOException;
+import java.util.List;
 
 /**
  * Base class to extractors that have a list (e.g. playlists, channels).
  */
 public abstract class ListExtractor extends Extractor {
     protected String nextStreamsUrl;
 
-    public ListExtractor(UrlIdHandler urlIdHandler, int serviceId, String url) {
-        super(urlIdHandler, serviceId, url);
+    /**
+     * Get a new ListExtractor with the given nextStreamsUrl set.
+     * <p>
+     * The extractor <b>WILL</b> fetch the page if {@link #fetchPageUponCreation()} return true, otherwise, it will <b>NOT</b>.
+     * <p>
+     * You can call {@link #fetchPage()} later, but this is mainly used just to get more items, so we don't waste bandwidth
+     * downloading the whole page, but if the service that is being implemented need it, just do its own logic in {@link #fetchPageUponCreation()}.
+     */
+    public ListExtractor(StreamingService service, String url, String nextStreamsUrl) throws IOException, ExtractionException {
+        super(service, url);
+        setNextStreamsUrl(nextStreamsUrl);
+
+        if (fetchPageUponCreation()) {
+            fetchPage();
+        }
     }
 
-    public boolean hasMoreStreams(){
-        return nextStreamsUrl != null && !nextStreamsUrl.isEmpty();
+    /**
+     * Decide if the page will be fetched upon creation.
+     * <p>
+     * The default implementation checks if the nextStreamsUrl is null or empty (indication that the caller
+     * don't need or know what is the next page, thus, fetch the page).
+     */
+    protected boolean fetchPageUponCreation() {
+        return nextStreamsUrl == null || nextStreamsUrl.isEmpty();
     }
 
-    public abstract StreamInfoItemCollector getNextStreams() throws ExtractionException, IOException;
+    public abstract StreamInfoItemCollector getStreams() throws IOException, ExtractionException;
+    public abstract NextItemsResult getNextStreams() throws IOException, ExtractionException;
+
+    public boolean hasMoreStreams() {
+        return nextStreamsUrl != null && !nextStreamsUrl.isEmpty();
+    }
 
     public String getNextStreamsUrl() {
         return nextStreamsUrl;
@@ -29,4 +54,29 @@ public void setNextStreamsUrl(String nextStreamsUrl) {
         this.nextStreamsUrl = nextStreamsUrl;
     }
 
+    /*//////////////////////////////////////////////////////////////////////////
+    // Inner
+    //////////////////////////////////////////////////////////////////////////*/
+
+    public static class NextItemsResult {
+        /**
+         * The current list of items to this result
+         */
+        public final List<InfoItem> nextItemsList;
+
+        /**
+         * Next url to fetch more items
+         */
+        public final String nextItemsUrl;
+
+        public NextItemsResult(List<InfoItem> nextItemsList, String nextItemsUrl) {
+            this.nextItemsList = nextItemsList;
+            this.nextItemsUrl = nextItemsUrl;
+        }
+
+        public boolean hasMoreStreams() {
+            return nextItemsUrl != null && !nextItemsUrl.isEmpty();
+        }
+    }
+
 }

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

@@ -0,0 +1,9 @@
+package org.schabi.newpipe.extractor;
+
+import java.util.List;
+
+public abstract class ListInfo extends Info {
+    public List<InfoItem> related_streams;
+    public boolean has_more_streams;
+    public String next_streams_url;
+}

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

@@ -1,7 +1,5 @@
 package org.schabi.newpipe.extractor;
 
-import org.schabi.newpipe.extractor.exceptions.ExtractionException;
-
 /*
  * Created by Christian Schabesberger on 23.08.15.
  *
@@ -22,70 +20,83 @@
  * along with NewPipe.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+import org.schabi.newpipe.extractor.exceptions.ExtractionException;
+
 /**
- * Provides access to the video streaming services supported by NewPipe.
- * Currently only Youtube until the API becomes more stable.
+ * Provides access to streaming services supported by NewPipe.
  */
-
-@SuppressWarnings("ALL")
 public class NewPipe {
     private static final String TAG = NewPipe.class.toString();
+    private static Downloader downloader = null;
 
     private NewPipe() {
     }
 
-    private static Downloader downloader = null;
+    public static void init(Downloader d) {
+        downloader = d;
+    }
+
+    public static Downloader getDownloader() {
+        return downloader;
+    }
+
+    /*//////////////////////////////////////////////////////////////////////////
+    // Utils
+    //////////////////////////////////////////////////////////////////////////*/
 
     public static StreamingService[] getServices() {
-        return ServiceList.serviceList;
+        final ServiceList[] values = ServiceList.values();
+        final StreamingService[] streamingServices = new StreamingService[values.length];
+
+        for (int i = 0; i < values.length; i++) streamingServices[i] = values[i].getService();
+
+        return streamingServices;
     }
 
     public static StreamingService getService(int serviceId) throws ExtractionException {
-        for (StreamingService s : ServiceList.serviceList) {
-            if (s.getServiceId() == serviceId) {
-                return s;
+        for (ServiceList item : ServiceList.values()) {
+            if (item.getService().getServiceId() == serviceId) {
+                return item.getService();
             }
         }
-        return null;
+        throw new ExtractionException("There's no service with the id = \"" + serviceId + "\"");
     }
 
     public static StreamingService getService(String serviceName) throws ExtractionException {
-        return ServiceList.serviceList[getIdOfService(serviceName)];
-    }
-
-    public static String getNameOfService(int id) {
-        try {
-            return getService(id).getServiceInfo().name;
-        } catch (Exception e) {
-            System.err.println("Service id not known");
-            e.printStackTrace();
-            return "";
+        for (ServiceList item : ServiceList.values()) {
+            if (item.getService().getServiceInfo().name.equals(serviceName)) {
+                return item.getService();
+            }
         }
+        throw new ExtractionException("There's no service with the name = \"" + serviceName + "\"");
     }
 
-    public static int getIdOfService(String serviceName) {
-        for (int i = 0; i < ServiceList.serviceList.length; i++) {
-            if (ServiceList.serviceList[i].getServiceInfo().name.equals(serviceName)) {
-                return i;
+    public static StreamingService getServiceByUrl(String url) throws ExtractionException {
+        for (ServiceList item : ServiceList.values()) {
+            if (item.getService().getLinkTypeByUrl(url) != StreamingService.LinkType.NONE) {
+                return item.getService();
             }
         }
-        return -1;
+        throw new ExtractionException("No service can handle the url = \"" + url + "\"");
     }
 
-    public static void init(Downloader d) {
-        downloader = d;
-    }
-
-    public static Downloader getDownloader() {
-        return downloader;
+    public static int getIdOfService(String serviceName) {
+        try {
+            //noinspection ConstantConditions
+            return getService(serviceName).getServiceId();
+        } catch (ExtractionException ignored) {
+            return -1;
+        }
     }
 
-    public static StreamingService getServiceByUrl(String url) {
-        for (StreamingService s : ServiceList.serviceList) {
-            if (s.getLinkTypeByUrl(url) != StreamingService.LinkType.NONE) {
-                return s;
-            }
+    public static String getNameOfService(int id) {
+        try {
+            //noinspection ConstantConditions
+            return getService(id).getServiceInfo().name;
+        } catch (Exception e) {
+            System.err.println("Service id not known");
+            e.printStackTrace();
+            return "<unknown>";
         }
-        return null;
     }
 }