Allow common messages to be specified for message sources

Extend the configuration schema to support the specification of common messages, when defining a messageSource bean

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfiguration.java

@@ -16,10 +16,16 @@
 
 package org.springframework.boot.autoconfigure.context;
 
+import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.time.Duration;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
 
 import org.springframework.aot.hint.RuntimeHints;
 import org.springframework.aot.hint.RuntimeHintsRegistrar;
+import org.springframework.beans.factory.config.PropertiesFactoryBean;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.AutoConfigureOrder;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
@@ -39,7 +45,9 @@
 import org.springframework.context.support.AbstractApplicationContext;
 import org.springframework.context.support.ResourceBundleMessageSource;
 import org.springframework.core.Ordered;
+import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.Resource;
+import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
 import org.springframework.core.type.AnnotatedTypeMetadata;
 import org.springframework.util.ConcurrentReferenceHashMap;
@@ -81,6 +89,25 @@ public MessageSource messageSource(MessageSourceProperties properties) {
 }
 messageSource.setAlwaysUseMessageFormat(properties.isAlwaysUseMessageFormat());
 messageSource.setUseCodeAsDefaultMessage(properties.isUseCodeAsDefaultMessage());
+
+try {
+if (StringUtils.hasText(properties.getCommonMessages())) {
+PropertiesFactoryBean propertiesFactory = new PropertiesFactoryBean();
+ResourceLoader resourceLoader = new DefaultResourceLoader();
+String[] commonMessages = StringUtils.commaDelimitedListToStringArray(
+StringUtils.trimAllWhitespace(properties.getCommonMessages()));
+List<Resource> commonResources = Arrays.stream(commonMessages)
+.map(resourceLoader::getResource)
+.toList();
+propertiesFactory.setLocations(commonResources.toArray(Resource[]::new));
+propertiesFactory.setSingleton(true);
+propertiesFactory.setIgnoreResourceNotFound(true);
+propertiesFactory.afterPropertiesSet();
+messageSource.setCommonMessages(propertiesFactory.getObject());
+}
+} catch (IOException e) {
+throw new UncheckedIOException("Failed to load common messages", e);
+}
 return messageSource;
 }
 

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/context/MessageSourceProperties.java

@@ -42,6 +42,11 @@ public class MessageSourceProperties {
  */
 private String basename = "messages";
 
+/**
+ * Comma-separated list of locale-independent common messages.
+ */
+private String commonMessages;
+
 /**
  * Message bundles encoding.
  */
@@ -121,4 +126,11 @@ public void setUseCodeAsDefaultMessage(boolean useCodeAsDefaultMessage) {
 this.useCodeAsDefaultMessage = useCodeAsDefaultMessage;
 }
 
+public String getCommonMessages() {
+return this.commonMessages;
+}
+
+public void setCommonMessages(String commonMessages) {
+this.commonMessages = commonMessages;
+}
 }

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/context/MessageSourceAutoConfigurationTests.java

@@ -116,6 +116,12 @@ void testMessageSourceFromPropertySourceAnnotation() {
 .run((context) -> assertThat(context.getMessage("foo", null, "Foo message", Locale.UK)).isEqualTo("bar"));
 }
 
+@Test
+void testCommonMessages() {
+this.contextRunner.withPropertyValues("spring.messages.basename:test/messages", "spring.messages.common-messages:test/common-messages")
+.run((context) -> assertThat(context.getMessage("hello", null, "Hello!", Locale.UK)).isEqualTo("world"));
+}
+
 @Test
 void testFallbackDefault() {
 this.contextRunner.withPropertyValues("spring.messages.basename:test/messages")

spring-boot-project/spring-boot-autoconfigure/src/test/resources/test/common-messages.properties

@@ -0,0 +1 @@
+hello=world