remove static language and read i18dir in constructor

src/main/java/org/cryptomator/launcher/SupportedLanguages.java

@@ -15,41 +15,12 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
-import java.util.Optional;
-import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 
 @Singleton
 public class SupportedLanguages {
 
 	private static final Logger LOG = LoggerFactory.getLogger(SupportedLanguages.class);
-	// these are BCP 47 language codes, not ISO. Note the "-" instead of the "_":
-	public static final List<String> LANGUAGE_TAGS;
-
-	static {
-		List<String> supportedLanguages = new ArrayList<>();
-		try {
-			var i18Dir = getI18Dir();
-			try (var dirStream = Files.newDirectoryStream(i18Dir, "strings_*.properties")) {
-				StreamSupport.stream(dirStream.spliterator(), false) //
-						.map(SupportedLanguages::getBCP47CodeFromFileName) //
-						.forEach(supportedLanguages::add);
-			}
-		} catch (URISyntaxException | IOException e) {
-			LOG.warn("Unable to determine additional supported languages.", e);
-		}
-		LANGUAGE_TAGS = supportedLanguages;
-	}
-
-	private static Path getI18Dir() throws URISyntaxException {
-		var i18nUri = Optional.of(SupportedLanguages.class.getResource("/i18n")).get().toURI();
-		return Path.of(i18nUri);
-	}
-
-	private static String getBCP47CodeFromFileName(Path p) {
-		var fileName = p.getFileName().toString();
-		return fileName.substring("strings_".length(), fileName.indexOf(".properties")).replace('_', '-');
-	}
 
 	public static final String ENGLISH = "en";
 
@@ -63,12 +34,13 @@ public class SupportedLanguages {
 		preferredLocale = preferredLanguage == null ? Locale.getDefault() : Locale.forLanguageTag(preferredLanguage);
 		var collator = Collator.getInstance(preferredLocale);
 		collator.setStrength(Collator.PRIMARY);
-		var sorted = LANGUAGE_TAGS.stream() //
+		List<String> sortedTags = new ArrayList<>();
+		sortedTags.add(0, Settings.DEFAULT_LANGUAGE);
+		sortedTags.add(1, ENGLISH);
+		getSupportedLanguageTags().stream() //
 				.sorted((a, b) -> collator.compare(Locale.forLanguageTag(a).getDisplayName(), Locale.forLanguageTag(b).getDisplayName())) //
-				.collect(Collectors.toList());
-		sorted.add(0, Settings.DEFAULT_LANGUAGE);
-		sorted.add(1, ENGLISH);
-		sortedLanguageTags = Collections.unmodifiableList(sorted);
+				.forEach(sortedTags::add);
+		sortedLanguageTags = Collections.unmodifiableList(sortedTags);
 	}
 
 	public void applyPreferred() {
@@ -80,4 +52,29 @@ public class SupportedLanguages {
 		return sortedLanguageTags;
 	}
 
+
+	/**
+	 * Iterates over the /i18n directory and extracts from every localization file  the BCP 47 code.
+	 *
+	 * @return list of supported BCP 47 language codes
+	 */
+	private static List<String> getSupportedLanguageTags() {
+		try {
+			var i18Dir = Path.of(SupportedLanguages.class.getResource("/i18n").toURI());
+			try (var dirStream = Files.newDirectoryStream(i18Dir, "strings_*.properties")) {
+				return StreamSupport.stream(dirStream.spliterator(), false) //
+						.map(SupportedLanguages::getBCP47CodeFromFileName) //
+						.toList();
+			}
+		} catch (URISyntaxException | IOException e) {
+			LOG.warn("Unable to determine additional supported languages.", e);
+			return List.of();
+		}
+	}
+
+	private static String getBCP47CodeFromFileName(Path p) {
+		var fileName = p.getFileName().toString();
+		return fileName.substring("strings_".length(), fileName.indexOf(".properties")).replace('_', '-');
+	}
+
 }

src/test/java/org/cryptomator/launcher/SupportedLanguagesTest.java

@@ -1,31 +0,0 @@
-package org.cryptomator.launcher;
-
-import org.junit.jupiter.api.Assertions;
-import org.junit.jupiter.api.DisplayName;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.MethodSource;
-
-import java.util.Locale;
-import java.util.ResourceBundle;
-import java.util.stream.Stream;
-
-public class SupportedLanguagesTest {
-
-	@DisplayName("test if resource bundle is localized")
-	@ParameterizedTest(name = "{0}")
-	@MethodSource("languageTags")
-	public void testResourceBundleExists(String tag) {
-		var locale = Locale.forLanguageTag(tag);
-		Assertions.assertNotEquals("und", locale.toLanguageTag(), "Undefined language tag");
-
-		var bundle = Assertions.assertDoesNotThrow(() -> ResourceBundle.getBundle("i18n.strings", locale));
-
-		Assertions.assertEquals(locale, bundle.getLocale());
-		Assertions.assertFalse(bundle.keySet().isEmpty());
-	}
-
-	public static Stream<String> languageTags() {
-		return SupportedLanguages.LANGUAGE_TAGS.stream() //
-				.filter(tag -> !"en".equals(tag)); // english uses the default bundle
-	}
-}