refactor: add Utils.isNullOrEmpty()

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

@@ -2,13 +2,16 @@
 
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.linkhandler.ListLinkHandler;
+import org.schabi.newpipe.extractor.utils.Utils;
 
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
 
 import javax.annotation.Nonnull;
 
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
+
 /**
  * Base class to extractors that have a list (e.g. playlists, users).
  */
@@ -63,8 +66,7 @@ public ListExtractor(StreamingService service, ListLinkHandler linkHandler) {
     public abstract InfoItemsPage<R> getPage(final String pageUrl) throws IOException, ExtractionException;
 
     public boolean hasNextPage() throws IOException, ExtractionException {
-        final String nextPageUrl = getNextPageUrl();
-        return nextPageUrl != null && !nextPageUrl.isEmpty();
+        return !isNullOrEmpty(getNextPageUrl());
     }
 
     @Override
@@ -123,7 +125,7 @@ public InfoItemsPage(List<T> itemsList, String nextPageUrl, List<Throwable> erro
         }
 
         public boolean hasNextPage() {
-            return nextPageUrl != null && !nextPageUrl.isEmpty();
+            return !isNullOrEmpty(nextPageUrl);
         }
 
         public List<T> getItems() {

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

@@ -4,6 +4,8 @@
 
 import java.util.List;
 
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
+
 public abstract class ListInfo<T extends InfoItem> extends Info {
     private List<T> relatedItems;
     private String nextPageUrl = null;
@@ -37,7 +39,7 @@ public void setRelatedItems(List<T> relatedItems) {
     }
 
     public boolean hasNextPage() {
-        return nextPageUrl != null && !nextPageUrl.isEmpty();
+        return !isNullOrEmpty(nextPageUrl);
     }
 
     public String getNextPageUrl() {

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

@@ -21,6 +21,7 @@
 import org.schabi.newpipe.extractor.stream.StreamInfoItemsCollector;
 import org.schabi.newpipe.extractor.utils.Parser;
 import org.schabi.newpipe.extractor.utils.Parser.RegexException;
+import org.schabi.newpipe.extractor.utils.Utils;
 
 import javax.annotation.Nonnull;
 import java.io.IOException;
@@ -32,6 +33,7 @@
 import static java.util.Collections.singletonList;
 import static org.schabi.newpipe.extractor.ServiceList.SoundCloud;
 import static org.schabi.newpipe.extractor.utils.JsonUtils.EMPTY_STRING;
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
 import static org.schabi.newpipe.extractor.utils.Utils.replaceHttpWithHttps;
 
 public class SoundcloudParsingHelper {
@@ -42,7 +44,7 @@ private SoundcloudParsingHelper() {
     }
 
     public static String clientId() throws ExtractionException, IOException {
-        if (clientId != null && !clientId.isEmpty()) return clientId;
+        if (!isNullOrEmpty(clientId)) return clientId;
 
         Downloader dl = NewPipe.getDownloader();
         clientId = HARDCODED_CLIENT_ID;
@@ -64,7 +66,7 @@ public static String clientId() throws ExtractionException, IOException {
 
         for (Element element : possibleScripts) {
             final String srcUrl = element.attr("src");
-            if (srcUrl != null && !srcUrl.isEmpty()) {
+            if (!isNullOrEmpty(srcUrl)) {
                 try {
                     return clientId = Parser.matchGroup1(clientIdPattern, dl.get(srcUrl, headers).responseBody());
                 } catch (RegexException ignored) {

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

@@ -18,6 +18,7 @@
 import java.io.IOException;
 
 import static org.schabi.newpipe.extractor.utils.JsonUtils.EMPTY_STRING;
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
 
 @SuppressWarnings("WeakerAccess")
 public class SoundcloudChannelExtractor extends ChannelExtractor {
@@ -132,7 +133,7 @@ private void computeNextPageAndGetStreams() throws ExtractionException {
 
     @Override
     public InfoItemsPage<StreamInfoItem> getPage(final String pageUrl) throws IOException, ExtractionException {
-        if (pageUrl == null || pageUrl.isEmpty()) {
+        if (isNullOrEmpty(pageUrl)) {
             throw new ExtractionException(new IllegalArgumentException("Page url is empty or null"));
         }
 

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

@@ -13,6 +13,7 @@
 import java.io.IOException;
 
 import static org.schabi.newpipe.extractor.ServiceList.SoundCloud;
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
 
 public class SoundcloudChartsExtractor extends KioskExtractor<StreamInfoItem> {
     private StreamInfoItemsCollector collector = null;
@@ -36,7 +37,7 @@ public String getName() {
 
     @Override
     public InfoItemsPage<StreamInfoItem> getPage(String pageUrl) throws IOException, ExtractionException {
-        if (pageUrl == null || pageUrl.isEmpty()) {
+        if (isNullOrEmpty(pageUrl)) {
             throw new ExtractionException(new IllegalArgumentException("Page url is empty or null"));
         }
 

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

@@ -21,6 +21,8 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
+
 @SuppressWarnings("WeakerAccess")
 public class SoundcloudPlaylistExtractor extends PlaylistExtractor {
     private static final int streamsPerRequestedPage = 15;
@@ -76,7 +78,7 @@ public String getThumbnailUrl() {
 
                 for (StreamInfoItem item : infoItems.getItems()) {
                     artworkUrl = item.getThumbnailUrl();
-                    if (artworkUrl != null && !artworkUrl.isEmpty()) break;
+                    if (!isNullOrEmpty(artworkUrl)) break;
                 }
             } catch (Exception ignored) {
             }
@@ -160,7 +162,7 @@ public String getNextPageUrl() throws IOException, ExtractionException {
 
     @Override
     public InfoItemsPage<StreamInfoItem> getPage(String pageUrl) throws IOException, ExtractionException {
-        if (pageUrl == null || pageUrl.isEmpty()) {
+        if (isNullOrEmpty(pageUrl)) {
             throw new ExtractionException(new IllegalArgumentException("Page url is empty or null"));
         }
 

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

@@ -36,6 +36,7 @@
 import javax.annotation.Nonnull;
 
 import static org.schabi.newpipe.extractor.utils.JsonUtils.EMPTY_STRING;
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
 
 public class SoundcloudStreamExtractor extends StreamExtractor {
     private JsonObject track;
@@ -191,7 +192,7 @@ public List<AudioStream> getAudioStreams() throws IOException, ExtractionExcepti
                 JsonObject t = (JsonObject) transcoding;
                 String url = t.getString("url");
 
-                if (url != null && !url.isEmpty()) {
+                if (!isNullOrEmpty(url)) {
 
                     // We can only play the mp3 format, but not handle m3u playlists / streams.
                     // what about Opus?

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

@@ -29,8 +29,7 @@
 
 import static org.schabi.newpipe.extractor.NewPipe.getDownloader;
 import static org.schabi.newpipe.extractor.utils.JsonUtils.EMPTY_STRING;
-import static org.schabi.newpipe.extractor.utils.Utils.HTTP;
-import static org.schabi.newpipe.extractor.utils.Utils.HTTPS;
+import static org.schabi.newpipe.extractor.utils.Utils.*;
 
 /*
  * Created by Christian Schabesberger on 02.03.16.
@@ -202,7 +201,7 @@ public static boolean isHardcodedClientVersionValid() throws IOException, Extrac
      * @throws ParsingException
      */
     public static String getClientVersion() throws IOException, ExtractionException {
-        if (clientVersion != null && !clientVersion.isEmpty()) return clientVersion;
+        if (!isNullOrEmpty(clientVersion)) return clientVersion;
         if (isHardcodedClientVersionValid()) return clientVersion = HARDCODED_CLIENT_VERSION;
 
         final String url = "https://www.youtube.com/results?search_query=test";
@@ -245,7 +244,7 @@ public static String getClientVersion() throws IOException, ExtractionException
         for (String pattern : patterns) {
             try {
                 contextClientVersion = Parser.matchGroup1(pattern, html);
-                if (contextClientVersion != null && !contextClientVersion.isEmpty()) {
+                if (!isNullOrEmpty(contextClientVersion)) {
                     return clientVersion = contextClientVersion;
                 }
             } catch (Exception ignored) {
@@ -365,7 +364,7 @@ public static String getUrlFromNavigationEndpoint(JsonObject navigationEndpoint)
                 return "https://www.youtube.com/channel/" + browseId;
             }
 
-            if (canonicalBaseUrl != null && !canonicalBaseUrl.isEmpty()) {
+            if (!isNullOrEmpty(canonicalBaseUrl)) {
                 return "https://www.youtube.com" + canonicalBaseUrl;
             }
 
@@ -392,7 +391,7 @@ public static String getUrlFromNavigationEndpoint(JsonObject navigationEndpoint)
      * @return text in the JSON object or {@code null}
      */
     public static String getTextFromObject(JsonObject textObject, boolean html) throws ParsingException {
-        if (textObject == null || textObject.isEmpty()) return null;
+        if (isNullOrEmpty(textObject)) return null;
 
         if (textObject.has("simpleText")) return textObject.getString("simpleText");
 
@@ -403,7 +402,7 @@ public static String getTextFromObject(JsonObject textObject, boolean html) thro
             String text = ((JsonObject) textPart).getString("text");
             if (html && ((JsonObject) textPart).has("navigationEndpoint")) {
                 String url = getUrlFromNavigationEndpoint(((JsonObject) textPart).getObject("navigationEndpoint"));
-                if (url != null && !url.isEmpty()) {
+                if (!isNullOrEmpty(url)) {
                     textBuilder.append("<a href=\"").append(url).append("\">").append(text).append("</a>");
                     continue;
                 }
@@ -497,7 +496,7 @@ public static JsonArray getJsonResponse(final String url, final Localization loc
      */
     public static void defaultAlertsCheck(final JsonObject initialData) throws ParsingException {
         final JsonArray alerts = initialData.getArray("alerts");
-        if (!alerts.isEmpty()) {
+        if (!isNullOrEmpty(alerts)) {
             final JsonObject alertRenderer = alerts.getObject(0).getObject("alertRenderer");
             final String alertText = getTextFromObject(alertRenderer.getObject("text"));
             final String alertType = alertRenderer.getString("type", EMPTY_STRING);

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

@@ -21,6 +21,7 @@
 
 import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.*;
 import static org.schabi.newpipe.extractor.utils.JsonUtils.EMPTY_STRING;
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
 
 /*
  * Created by Christian Schabesberger on 25.07.16.
@@ -130,7 +131,7 @@ public String getId() throws ParsingException {
 
         if (!channelId.isEmpty()) {
             return channelId;
-        } else if (redirectedChannelId != null && !redirectedChannelId.isEmpty()) {
+        } else if (!isNullOrEmpty(redirectedChannelId)) {
             return redirectedChannelId;
         } else {
             throw new ParsingException("Could not get channel id");
@@ -244,7 +245,7 @@ public InfoItemsPage<StreamInfoItem> getInitialPage() throws ExtractionException
 
     @Override
     public InfoItemsPage<StreamInfoItem> getPage(String pageUrl) throws IOException, ExtractionException {
-        if (pageUrl == null || pageUrl.isEmpty()) {
+        if (isNullOrEmpty(pageUrl)) {
             throw new ExtractionException(new IllegalArgumentException("Page url is empty or null"));
         }
 
@@ -265,7 +266,7 @@ public InfoItemsPage<StreamInfoItem> getPage(String pageUrl) throws IOException,
 
 
     private String getNextPageUrlFrom(JsonArray continuations) {
-        if (continuations == null || continuations.isEmpty()) {
+        if (isNullOrEmpty(continuations)) {
             return "";
         }
 

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

@@ -27,6 +27,7 @@
 import java.util.regex.Pattern;
 
 import static java.util.Collections.singletonList;
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
 
 
 public class YoutubeCommentsExtractor extends CommentsExtractor {
@@ -91,7 +92,7 @@ private String getNextPageUrl(String continuation) throws ParsingException {
 
     @Override
     public InfoItemsPage<CommentsInfoItem> getPage(String pageUrl) throws IOException, ExtractionException {
-        if (pageUrl == null || pageUrl.isEmpty()) {
+        if (isNullOrEmpty(pageUrl)) {
             throw new ExtractionException(new IllegalArgumentException("Page url is empty or null"));
         }
         String ajaxResponse = makeAjaxRequest(pageUrl);

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

@@ -11,6 +11,8 @@
 
 import javax.annotation.Nullable;
 
+import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
+
 public class YoutubeCommentsInfoItemExtractor implements CommentsInfoItemExtractor {
 
     private final JsonObject json;