spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationProperties.java

@@ -39,6 +39,7 @@
  * values are externalized.
  *
  * @author Dave Syer
+ * @author Yanming Zhou
  * @since 1.0.0
  * @see ConfigurationPropertiesScan
  * @see ConstructorBinding
@@ -69,6 +70,14 @@
 	@AliasFor("value")
 	String prefix() default "";
 
+	/**
+	 * The prefix of the properties that {@link #prefix()} will inherit, It's used for
+	 * configuring multiple beans which share common properties.
+	 * @return the prefix of the properties to inherit
+	 * @see #prefix()
+	 */
+	String inheritedPrefix() default "";
+
 	/**
 	 * Flag to indicate that when binding to this object invalid fields should be ignored.
 	 * Invalid means invalid according to the binder that is used, and usually this means

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBinder.java

@@ -17,7 +17,9 @@
 package org.springframework.boot.context.properties;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.function.Consumer;
 
 import org.springframework.beans.BeansException;
@@ -49,8 +51,13 @@
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.core.annotation.MergedAnnotations;
 import org.springframework.core.convert.ConversionService;
+import org.springframework.core.env.EnumerablePropertySource;
+import org.springframework.core.env.MapPropertySource;
+import org.springframework.core.env.MutablePropertySources;
+import org.springframework.core.env.PropertySource;
 import org.springframework.core.env.PropertySources;
 import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 import org.springframework.validation.Errors;
 import org.springframework.validation.Validator;
 import org.springframework.validation.annotation.Validated;
@@ -61,6 +68,7 @@
  *
  * @author Stephane Nicoll
  * @author Phillip Webb
+ * @author Yanming Zhou
  */
 class ConfigurationPropertiesBinder {
 
@@ -91,14 +99,16 @@ BindResult<?> bind(ConfigurationPropertiesBean propertiesBean) {
 		Bindable<?> target = propertiesBean.asBindTarget();
 		ConfigurationProperties annotation = propertiesBean.getAnnotation();
 		BindHandler bindHandler = getBindHandler(target, annotation);
-		return getBinder().bind(annotation.prefix(), target, bindHandler);
+		Binder binder = getBinder(target, annotation);
+		return binder.bind(annotation.prefix(), target, bindHandler);
 	}
 
 	Object bindOrCreate(ConfigurationPropertiesBean propertiesBean) {
 		Bindable<?> target = propertiesBean.asBindTarget();
 		ConfigurationProperties annotation = propertiesBean.getAnnotation();
 		BindHandler bindHandler = getBindHandler(target, annotation);
-		return getBinder().bindOrCreate(annotation.prefix(), target, bindHandler);
+		Binder binder = getBinder(target, annotation);
+		return binder.bindOrCreate(annotation.prefix(), target, bindHandler);
 	}
 
 	private Validator getConfigurationPropertiesValidator(ApplicationContext applicationContext) {
@@ -178,7 +188,36 @@ private Validator getJsr303Validator(Class<?> type) {
 		return new ConfigurationPropertiesJsr303Validator(this.applicationContext, type);
 	}
 
-	private Binder getBinder() {
+	private <T> Binder getBinder(Bindable<T> target, ConfigurationProperties annotation) {
+		return StringUtils.hasText(annotation.prefix()) && StringUtils.hasText(annotation.inheritedPrefix())
+				? createBinderForInheritedPrefix(annotation.prefix(), annotation.inheritedPrefix()) : getDefaultBinder();
+	}
+
+	private Binder createBinderForInheritedPrefix(String prefix, String inheritedPrefix) {
+		MutablePropertySources propertySourcesToUse = new MutablePropertySources(this.propertySources);
+		propertySourcesToUse.addLast(createPropertySourceForInheritedPrefix(prefix, inheritedPrefix));
+		return new Binder(ConfigurationPropertySources.from(propertySourcesToUse),
+				getPropertySourcesPlaceholdersResolver(), getConversionServices(), getPropertyEditorInitializer(), null,
+				null);
+	}
+
+	private PropertySource<?> createPropertySourceForInheritedPrefix(String prefix, String inheritedPrefix) {
+		Map<String, Object> map = new HashMap<>();
+		for (PropertySource<?> propertySource : this.propertySources) {
+			if (propertySource instanceof EnumerablePropertySource<?> enumerablePropertySource) {
+				for (String key : enumerablePropertySource.getPropertyNames()) {
+					if (key.startsWith(inheritedPrefix + '.')) {
+						map.put(prefix + '.' + key.substring(inheritedPrefix.length() + 1),
+								enumerablePropertySource.getProperty(key));
+					}
+				}
+			}
+		}
+		return new MapPropertySource(
+				"MapPropertySource for prefix '%s' inheriting from '%s'".formatted(prefix, inheritedPrefix), map);
+	}
+
+	private Binder getDefaultBinder() {
 		if (this.binder == null) {
 			this.binder = new Binder(getConfigurationPropertySources(), getPropertySourcesPlaceholdersResolver(),
 					getConversionServices(), getPropertyEditorInitializer(), null, null);

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesTests.java

@@ -129,6 +129,7 @@
  * @author Stephane Nicoll
  * @author Madhura Bhave
  * @author Vladislav Kisel
+ * @author Yanming Zhou
  */
 @ExtendWith(OutputCaptureExtension.class)
 class ConfigurationPropertiesTests {
@@ -1271,6 +1272,25 @@ void loadWhenBindingToJavaBeanWithConversionToCustomListImplementation() {
 		assertThat(this.context.getBean(SetterBoundCustomListProperties.class).getValues()).containsExactly("a", "b");
 	}
 
+	@Test
+	void loadWhenUsingInheritedPrefixForJavaBeanBinder() {
+		load(SetterBoundInheritedPrefixConfiguration.class, "spring.service.host=127.0.0.1", "spring.service.port=6379",
+				"additional.service.port=6380");
+		SetterBoundServiceProperties properties = this.context.getBean("additionalServiceProperties",
+				SetterBoundServiceProperties.class);
+		assertThat(properties.getPort()).isEqualTo(6380);
+		assertThat(properties.getHost()).isEqualTo("127.0.0.1");
+	}
+
+	@Test
+	void loadWhenUsingInheritedPrefixForValueObjectBinder() {
+		load(ConstructorBoundInheritedPrefixConfiguration.class, "spring.service.host=127.0.0.1",
+				"spring.service.port=6379", "additional.service.port=6380");
+		ConstructorBoundServiceProperties properties = this.context.getBean(ConstructorBoundServiceProperties.class);
+		assertThat(properties.getPort()).isEqualTo(6380);
+		assertThat(properties.getHost()).isEqualTo("127.0.0.1");
+	}
+
 	private AnnotationConfigApplicationContext load(Class<?> configuration, String... inlinedProperties) {
 		return load(new Class<?>[] { configuration }, inlinedProperties);
 	}
@@ -3311,4 +3331,68 @@ static final class CustomList<E> extends ArrayList<E> {
 
 	}
 
+	@ConfigurationProperties(prefix = "spring.service")
+	static class SetterBoundServiceProperties {
+
+		private String host = "localhost";
+
+		private int port = 6379;
+
+		String getHost() {
+			return this.host;
+		}
+
+		void setHost(String host) {
+			this.host = host;
+		}
+
+		int getPort() {
+			return this.port;
+		}
+
+		void setPort(int port) {
+			this.port = port;
+		}
+
+	}
+
+	@EnableConfigurationProperties(SetterBoundServiceProperties.class)
+	static class SetterBoundInheritedPrefixConfiguration {
+
+		@Bean(defaultCandidate = false) // do not back off auto-configured one
+		@ConfigurationProperties(prefix = "additional.service", inheritedPrefix = "spring.service")
+		SetterBoundServiceProperties additionalServiceProperties() {
+			return new SetterBoundServiceProperties();
+		}
+
+	}
+
+	@ConfigurationProperties(prefix = "additional.service", inheritedPrefix = "spring.service")
+	static class ConstructorBoundServiceProperties {
+
+		private final String host;
+
+		private final int port;
+
+		public ConstructorBoundServiceProperties(@DefaultValue("localhost") String host,
+				@DefaultValue("6379") int port) {
+			this.host = host;
+			this.port = port;
+		}
+
+		String getHost() {
+			return this.host;
+		}
+
+		int getPort() {
+			return this.port;
+		}
+
+	}
+
+	@EnableConfigurationProperties(ConstructorBoundServiceProperties.class)
+	static class ConstructorBoundInheritedPrefixConfiguration {
+
+	}
+
 }