Adapt locales support for GraalVM >= 24.2

Starting with GraalVM for JDK 24 (24.2) native image will no longer set
the locale default at build time. As a result, the default locale won't
be included by default in the native image unless explicitly specified.

See oracle/graal#9694

core/deployment/src/main/java/io/quarkus/deployment/pkg/NativeConfig.java

@@ -88,7 +88,8 @@ public interface NativeConfig {
 
     /**
      * Defines the user language used for building the native executable.
-     * It also serves as the default Locale language for the native executable application runtime.
+     * With GraalVM versiond prior to GraalVM for JDK 24 it also serves as the default Locale language for the native executable
+     * application runtime.
      * e.g. en or cs as defined by IETF BCP 47 language tags.
      * <p>
      *
@@ -100,7 +101,8 @@ public interface NativeConfig {
 
     /**
      * Defines the user country used for building the native executable.
-     * It also serves as the default Locale country for the native executable application runtime.
+     * With GraalVM versiond prior to GraalVM for JDK 24 it also serves as the default Locale country for the native executable
+     * application runtime.
      * e.g. US or FR as defined by ISO 3166-1 alpha-2 codes.
      * <p>
      *

core/deployment/src/main/java/io/quarkus/deployment/pkg/steps/GraalVM.java

@@ -193,6 +193,8 @@ public static final class Version implements Comparable<Version> {
         public static final Version VERSION_23_0_0 = new Version("GraalVM 23.0.0", "23.0.0", "17", Distribution.GRAALVM);
         public static final Version VERSION_23_1_0 = new Version("GraalVM 23.1.0", "23.1.0", "21", Distribution.GRAALVM);
         public static final Version VERSION_24_0_0 = new Version("GraalVM 24.0.0", "24.0.0", "22", Distribution.GRAALVM);
+        public static final Version VERSION_24_1_0 = new Version("GraalVM 24.1.0", "24.1.0", "23", Distribution.GRAALVM);
+        public static final Version VERSION_24_2_0 = new Version("GraalVM 24.2.0", "24.2.0", "24", Distribution.GRAALVM);
 
         /**
          * The minimum version of GraalVM supported by Quarkus.

core/deployment/src/main/java/io/quarkus/deployment/steps/LocaleProcessor.java

@@ -139,13 +139,13 @@ public static String nativeImageIncludeLocales(NativeConfig nativeConfig, Locale
             return "all";
         }
 
-        // We subtract what we already declare for native-image's user.language or user.country.
+        // Ensure the default locale is included to ensure compatibility with GraalVM for JDK 24, which doesn't set the locale at build-time.
+        additionalLocales.add(localesBuildTimeConfig.defaultLocale);
         // Note the deprecated options still count.
-        additionalLocales.remove(localesBuildTimeConfig.defaultLocale);
         if (nativeConfig.userCountry().isPresent() && nativeConfig.userLanguage().isPresent()) {
-            additionalLocales.remove(new Locale(nativeConfig.userLanguage().get(), nativeConfig.userCountry().get()));
+            additionalLocales.add(new Locale(nativeConfig.userLanguage().get(), nativeConfig.userCountry().get()));
         } else if (nativeConfig.userLanguage().isPresent()) {
-            additionalLocales.remove(new Locale(nativeConfig.userLanguage().get()));
+            additionalLocales.add(new Locale(nativeConfig.userLanguage().get()));
         }
 
         return additionalLocales.stream()

core/runtime/src/main/java/io/quarkus/runtime/LocalesBuildTimeConfig.java

@@ -44,7 +44,8 @@ public class LocalesBuildTimeConfig {
      * For instance, the Hibernate Validator extension makes use of it.
      * <p>
      * Native-image build uses this property to derive {@code user.language} and {@code user.country} for the application's
-     * runtime.
+     * runtime. Starting with GraalVM for JDK 24 this option will not result in setting the default runtime locale, and
+     * any usages of it should be re-evaluated.
      */
     @ConfigItem(defaultValue = DEFAULT_LANGUAGE + "-" + DEFAULT_COUNTRY, defaultValueDocumentation = "Build system locale")
     public Locale defaultLocale;

integration-tests/locales/some/src/test/java/io/quarkus/locales/it/LocalesIT.java

@@ -10,6 +10,9 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
 
+import io.quarkus.test.junit.DisableIfBuiltWithGraalVMNewerThan;
+import io.quarkus.test.junit.DisableIfBuiltWithGraalVMOlderThan;
+import io.quarkus.test.junit.GraalVMVersion;
 import io.quarkus.test.junit.QuarkusIntegrationTest;
 import io.restassured.RestAssured;
 
@@ -81,7 +84,8 @@ public void testTimeZones(String zone, String language, String name) {
     }
 
     @Test
-    public void testDefaultLocale() {
+    @DisableIfBuiltWithGraalVMNewerThan(value = GraalVMVersion.GRAALVM_24_1_0)
+    public void testDefaultLocaleBefore24_2() {
         RestAssured.given().when()
                 .get("/default/de-CH")
                 .then()
@@ -94,6 +98,21 @@ public void testDefaultLocale() {
                 .log().all();
     }
 
+    @Test
+    @DisableIfBuiltWithGraalVMOlderThan(value = GraalVMVersion.GRAALVM_24_2_0)
+    public void testDefaultLocaleAfter24_1() {
+        RestAssured.given().when()
+                .get("/default/de-CH")
+                .then()
+                .statusCode(HttpStatus.SC_OK)
+                /*
+                 * "Schweiz" is the correct name for Switzerland in German.
+                 * German is the default language as per the application.properties.
+                 */
+                .body(is("Schweiz"))
+                .log().all();
+    }
+
     @Test
     public void testMissingLocaleSorryItaly() {
         RestAssured.given().when()

integration-tests/locales/some/src/test/resources/application.properties

@@ -3,3 +3,4 @@ quarkus.locales=de,fr-FR,ja,uk-UA
 # used in your application properties. This test uses it only to verify compatibility.
 quarkus.native.user-language=cs
 quarkus.default-locale=en-US
+quarkus.test.arg-line=-Duser.language=de

test-framework/junit5/src/main/java/io/quarkus/test/junit/GraalVMVersion.java

@@ -4,7 +4,9 @@
 
 public enum GraalVMVersion {
     GRAALVM_23_1_0(GraalVM.Version.VERSION_23_1_0),
-    GRAALVM_24_0_0(GraalVM.Version.VERSION_24_0_0);
+    GRAALVM_24_0_0(GraalVM.Version.VERSION_24_0_0),
+    GRAALVM_24_1_0(GraalVM.Version.VERSION_24_1_0),
+    GRAALVM_24_2_0(GraalVM.Version.VERSION_24_2_0);
 
     private final GraalVM.Version version;