From 36e31c06120367fc324482421decfc47284691ce Mon Sep 17 00:00:00 2001
From: Marc Becker <marc.becker@sap.com>
Date: Wed, 2 Aug 2023 13:30:12 +0000
Subject: [PATCH] Add resource hints for MessageSource

This only registers the default locations, not the one users can provide
via 'spring.messages.basename'.

This is similar to the approach taken for schema.sql and data.sql
in class SqlInitializationScriptsRuntimeHints.

See gh-36682
---
 .../context/MessageSourceAutoConfiguration.java   | 15 +++++++++++++++
 .../MessageSourceAutoConfigurationTests.java      | 13 +++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfiguration.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfiguration.java
index ed306db988..0ec92b6568 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfiguration.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfiguration.java
@@ -18,6 +18,8 @@ package org.springframework.boot.autoconfigure.context;
 
 import java.time.Duration;
 
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.RuntimeHintsRegistrar;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.AutoConfigureOrder;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
@@ -26,6 +28,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.SearchStrategy;
 import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
+import org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration.MessageSourceRuntimeHints;
 import org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration.ResourceBundleCondition;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
@@ -33,6 +36,7 @@ import org.springframework.context.MessageSource;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ConditionContext;
 import org.springframework.context.annotation.Conditional;
+import org.springframework.context.annotation.ImportRuntimeHints;
 import org.springframework.context.support.AbstractApplicationContext;
 import org.springframework.context.support.ResourceBundleMessageSource;
 import org.springframework.core.Ordered;
@@ -48,6 +52,7 @@ import org.springframework.util.StringUtils;
  * @author Dave Syer
  * @author Phillip Webb
  * @author Eddú Meléndez
+ * @author Marc Becker
  * @since 1.5.0
  */
 @AutoConfiguration
@@ -55,6 +60,7 @@ import org.springframework.util.StringUtils;
 @AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
 @Conditional(ResourceBundleCondition.class)
 @EnableConfigurationProperties
+@ImportRuntimeHints(MessageSourceRuntimeHints.class)
 public class MessageSourceAutoConfiguration {
 
 	private static final Resource[] NO_RESOURCES = {};
@@ -125,4 +131,13 @@ public class MessageSourceAutoConfiguration {
 
 	}
 
+	static class MessageSourceRuntimeHints implements RuntimeHintsRegistrar {
+
+		@Override
+		public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
+			hints.resources().registerPattern("messages.properties").registerPattern("messages_*.properties");
+		}
+
+	}
+
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfigurationTests.java
index 313624d877..e309831641 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfigurationTests.java
@@ -21,7 +21,10 @@ import java.util.Locale;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.predicate.RuntimeHintsPredicates;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration.MessageSourceRuntimeHints;
 import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.test.context.runner.ContextConsumer;
@@ -40,6 +43,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * @author Eddú Meléndez
  * @author Stephane Nicoll
  * @author Kedar Joshi
+ * @author Marc Becker
  */
 class MessageSourceAutoConfigurationTests {
 
@@ -180,6 +184,15 @@ class MessageSourceAutoConfigurationTests {
 			.run((context) -> assertThat(context.getMessage("foo", null, Locale.US)).isEqualTo("bar"));
 	}
 
+	@Test
+	void shouldRegisterDefaultHints() {
+		RuntimeHints hints = new RuntimeHints();
+		new MessageSourceRuntimeHints().registerHints(hints, getClass().getClassLoader());
+		assertThat(RuntimeHintsPredicates.resource().forResource("messages.properties")).accepts(hints);
+		assertThat(RuntimeHintsPredicates.resource().forResource("messages_de.properties")).accepts(hints);
+		assertThat(RuntimeHintsPredicates.resource().forResource("messages_zh-CN.properties")).accepts(hints);
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	@PropertySource("classpath:/switch-messages.properties")
 	static class Config {