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

.github/native-tests.json

@@ -105,7 +105,7 @@
         {
             "category": "Misc2",
             "timeout": 75,
-            "test-modules": "hibernate-validator, test-extension/tests, logging-gelf, mailer, native-config-profile, locales/all, locales/some",
+            "test-modules": "hibernate-validator, test-extension/tests, logging-gelf, mailer, native-config-profile, locales/all, locales/some, locales/default",
             "os-name": "ubuntu-latest"
         },
         {

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 versions 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 versions 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/pkg/steps/NativeImageBuildStep.java

@@ -749,6 +749,14 @@ public NativeImageInvokerInfo build() {
                     }
                 }
 
+                if (!Locale.getDefault().equals(localesBuildTimeConfig.defaultLocale)
+                        && graalVMVersion.compareTo(GraalVM.Version.VERSION_24_2_0) >= 0) {
+                    log.warn(
+                            "Your application is setting the 'quarkus.default-locale' configuration key. " +
+                                    "Starting with GraalVM/Mandrel for JDK 24 this configuration is being ignored and the " +
+                                    "default locale is always set at runtime based on the system default locale.");
+                }
+
                 final String userLanguage = LocaleProcessor.nativeImageUserLanguage(nativeConfig, localesBuildTimeConfig);
                 if (!userLanguage.isEmpty()) {
                     nativeImageArgs.add("-J-Duser.language=" + userLanguage);

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

@@ -139,13 +139,15 @@ public static String nativeImageIncludeLocales(NativeConfig nativeConfig, Locale
             return "all";
         }
 
-        // We subtract what we already declare for native-image's user.language or user.country.
-        // Note the deprecated options still count.
-        additionalLocales.remove(localesBuildTimeConfig.defaultLocale);
+        // GraalVM for JDK 24 doesn't include the default locale used at build time. We must explicitly include the
+        // specified locales - including the build-time locale.
+        // Note the deprecated options still count and take precedence.
         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()));
+        } else {
+            additionalLocales.add(localesBuildTimeConfig.defaultLocale);
         }
 
         return additionalLocales.stream()

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

@@ -44,8 +44,11 @@ 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.
+     * Instead, the Java configuration {@code user.language} and {@code user.country} will be used as the
+     * default when running the native image.
      */
-    @ConfigItem(defaultValue = DEFAULT_LANGUAGE + "-" + DEFAULT_COUNTRY, defaultValueDocumentation = "Build system locale")
+    @ConfigItem(defaultValue = DEFAULT_LANGUAGE + "-"
+            + DEFAULT_COUNTRY, defaultValueDocumentation = "Build system locale prior to GraalVM for JDK 24, or system default locale at image runtime with GraalVM for JDK 24 and better")
     public Locale defaultLocale;
 }

integration-tests/locales/default/pom.xml

@@ -0,0 +1,97 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"
+         xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>io.quarkus</groupId>
+        <artifactId>quarkus-integration-test-locales-parent</artifactId>
+        <version>999-SNAPSHOT</version>
+    </parent>
+    <artifactId>quarkus-integration-test-locales-default</artifactId>
+    <name>Quarkus - Integration Tests - Locales - Default</name>
+    <dependencies>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-rest</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-hibernate-validator</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-integration-test-locales-app</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+        <!-- test dependencies -->
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit5</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.rest-assured</groupId>
+            <artifactId>rest-assured</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- Minimal test dependencies to *-deployment artifacts for consistent build order -->
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-rest-deployment</artifactId>
+            <version>${project.version}</version>
+            <type>pom</type>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>*</groupId>
+                    <artifactId>*</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-hibernate-validator-deployment</artifactId>
+            <version>${project.version}</version>
+            <type>pom</type>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>*</groupId>
+                    <artifactId>*</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <resources>
+            <resource>
+                <directory>src/test/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+        <plugins>
+            <plugin>
+                <groupId>io.quarkus</groupId>
+                <artifactId>quarkus-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>build</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <forkCount>1</forkCount>
+                    <reuseForks>false</reuseForks>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

integration-tests/locales/default/src/main/java/io/quarkus/locales/it/DefaultLocaleResource.java

@@ -0,0 +1,26 @@
+package io.quarkus.locales.it;
+
+import jakarta.validation.constraints.Pattern;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+import jakarta.ws.rs.PathParam;
+import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.core.MediaType;
+import jakarta.ws.rs.core.Response;
+
+import org.jboss.logging.Logger;
+
+@Path("")
+public class DefaultLocaleResource extends LocalesResource {
+    private static final Logger LOG = Logger.getLogger(DefaultLocaleResource.class);
+
+    // @Pattern validation does nothing when placed in LocalesResource.
+    @GET
+    @Path("/hibernate-validator-test-validation-message-locale/{id}/")
+    @Produces(MediaType.TEXT_PLAIN)
+    public Response validationMessageLocale(
+            @Pattern(regexp = "A.*", message = "{pattern.message}") @PathParam("id") String id) {
+        LOG.infof("Triggering test: id: %s", id);
+        return Response.ok(id).build();
+    }
+}

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

@@ -0,0 +1,84 @@
+package io.quarkus.locales.it;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+
+import org.apache.http.HttpStatus;
+import org.jboss.logging.Logger;
+import org.junit.jupiter.api.Test;
+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;
+
+/**
+ * For the Native test cases to function, the operating system has to have locales support installed. A barebone system with
+ * only C.UTF-8 default locale available won't be able to pass the tests.
+ * <p>
+ * For example, this package satisfies the dependency on a RHEL 9 type of OS: glibc-all-langpacks
+ */
+@QuarkusIntegrationTest
+public class LocalesIT {
+
+    private static final Logger LOG = Logger.getLogger(LocalesIT.class);
+
+    @Test
+    @DisableIfBuiltWithGraalVMNewerThan(value = GraalVMVersion.GRAALVM_24_1_0)
+    public void testDefaultLocaleBefore24_2() {
+        RestAssured.given().when()
+                .get("/default/de-CH")
+                .then()
+                .statusCode(HttpStatus.SC_OK)
+                /*
+                 * "l-Iżvizzera" is the correct name for Switzerland in Maltese language.
+                 * Maltese is the default language as per quarkus.default-locale=mt-MT.
+                 */
+                .body(is("l-Iżvizzera"))
+                .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)
+                /*
+                 * "l-Iżvizzera" is the correct name for Switzerland in Maltese language.
+                 * Maltese is the default build-time language as per quarkus.default-locale=mt-MT, but not at run-time.
+                 * Note that this test will fail if the default run-time language is Maltese on the test machine,
+                 * this is unfortunate but also unlikely given the small population of Malta.
+                 */
+                .body(not("l-Iżvizzera"))
+                .log().all();
+    }
+
+    /**
+     * @see integration-tests/hibernate-validator/src/test/java/io/quarkus/it/hibernate/validator/HibernateValidatorFunctionalityTest.java
+     */
+    @ParameterizedTest
+    @CsvSource(value = {
+            // French locale is included, so it's used, because Croatian locale is not included
+            // and thus its property file ValidationMessages_hr_HR.properties is ignored.
+            "en-US;q=0.25,hr-HR;q=0.9,fr-FR;q=0.5,uk-UA;q=0.1|La valeur ne correspond pas à l'échantillon",
+            // Silent fallback to lingua franca.
+            "invalid string|Value is not in line with the pattern",
+            // French locale is available and included.
+            "en-US;q=0.25,hr-HR;q=1,fr-FR;q=0.5|La valeur ne correspond pas à l'échantillon"
+    }, delimiter = '|')
+    public void testValidationMessageLocale(String acceptLanguage, String expectedMessage) {
+        RestAssured.given()
+                .header("Accept-Language", acceptLanguage)
+                .when()
+                .get("/hibernate-validator-test-validation-message-locale/1")
+                .then()
+                .body(containsString(expectedMessage));
+    }
+
+}

integration-tests/locales/default/src/test/java/io/quarkus/locales/it/LocalesTest.java

@@ -0,0 +1,7 @@
+package io.quarkus.locales.it;
+
+import io.quarkus.test.junit.QuarkusTest;
+
+@QuarkusTest
+public class LocalesTest {
+}

integration-tests/locales/default/src/test/resources/ValidationMessages.properties

@@ -0,0 +1 @@
+pattern.message=Value is not in line with the pattern

integration-tests/locales/default/src/test/resources/ValidationMessages_fr_FR.properties

@@ -0,0 +1 @@
+pattern.message=La valeur ne correspond pas à l'échantillon

integration-tests/locales/default/src/test/resources/ValidationMessages_hr_HR.properties

@@ -0,0 +1 @@
+pattern.message=Vrijednost ne zadovoljava uzorak

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

@@ -0,0 +1,4 @@
+quarkus.locales=de,fr-FR,ja,uk-UA
+# Note that quarkus.native.user-language is deprecated and solely quarkus.default-locale should be
+# used in your application properties. This test uses it only to verify compatibility.
+quarkus.default-locale=mt-MT

integration-tests/locales/pom.xml

@@ -14,6 +14,7 @@
     <modules>
         <module>app</module>
         <module>all</module>
+        <module>default</module>
         <module>some</module>
     </modules>
 </project>

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 `quarkus.test.arg-line` in 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;