Add backport implementation of Locale.forLanguageTag().

Author: Isira-Seneviratne

extractor/src/main/java/org/schabi/newpipe/extractor/localization/Localization.java

@@ -1,6 +1,7 @@
 package org.schabi.newpipe.extractor.localization;
 
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
+import org.schabi.newpipe.extractor.utils.LocaleCompat;
 
 import java.io.Serializable;
 import java.util.ArrayList;
@@ -38,7 +39,7 @@ public static List<Localization> listFrom(final String... localizationCodeList)
      * @param localizationCode a localization code, formatted like {@link #getLocalizationCode()}
      */
     public static Localization fromLocalizationCode(final String localizationCode) {
-        return fromLocale(Locale.forLanguageTag(localizationCode));
+        return fromLocale(LocaleCompat.forLanguageTag(localizationCode));
     }
 
     public Localization(@Nonnull final String languageCode, @Nullable final String countryCode) {

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

@@ -4,6 +4,7 @@
 
 import org.schabi.newpipe.extractor.MediaFormat;
 import org.schabi.newpipe.extractor.services.youtube.ItagItem;
+import org.schabi.newpipe.extractor.utils.LocaleCompat;
 
 import java.util.Locale;
 
@@ -232,7 +233,7 @@ private SubtitlesStream(@Nonnull final String id,
                             final boolean autoGenerated,
                             @Nullable final String manifestUrl) {
         super(id, content, isUrl, mediaFormat, deliveryMethod, manifestUrl);
-        this.locale = Locale.forLanguageTag(languageCode);
+        this.locale = LocaleCompat.forLanguageTag(languageCode);
         this.code = languageCode;
         this.format = mediaFormat;
         this.autoGenerated = autoGenerated;

extractor/src/main/java/org/schabi/newpipe/extractor/utils/LocaleCompat.java

@@ -0,0 +1,36 @@
+package org.schabi.newpipe.extractor.utils;
+
+import java.util.Locale;
+
+public class LocaleCompat {
+    private LocaleCompat() {
+    }
+
+    // Source: LocaleListCompat's private forLanguageTagCompat() method.
+    // Use Locale.forLanguageTag() on API level >= 21 instead.
+    public static Locale forLanguageTag(final String str) {
+        if (str.contains("-")) {
+            String[] args = str.split("-", -1);
+            if (args.length > 2) {
+                return new Locale(args[0], args[1], args[2]);
+            } else if (args.length > 1) {
+                return new Locale(args[0], args[1]);
+            } else if (args.length == 1) {
+                return new Locale(args[0]);
+            }
+        } else if (str.contains("_")) {
+            String[] args = str.split("_", -1);
+            if (args.length > 2) {
+                return new Locale(args[0], args[1], args[2]);
+            } else if (args.length > 1) {
+                return new Locale(args[0], args[1]);
+            } else if (args.length == 1) {
+                return new Locale(args[0]);
+            }
+        } else {
+            return new Locale(str);
+        }
+
+        throw new IllegalArgumentException("Can not parse language tag: [" + str + "]");
+    }
+}