Support to inherit common properties for configuring multiple beans

It's used for configuring multiple beans (spring-projects#15732), we could extract common or use primary properties as parent now.

Take `org.springframework.boot.autoconfigure.data.redis.RedisProperties` for example, given:
```
# primary
spring.data.redis:
  host: 127.0.0.1
  port: 6379

# additional
additional.data.redis:
  port: 6380
```
Then effective properties:
```
additional.data.redis:
  host: 127.0.0.1
  port: 6380
```
should be bound to `additionalRedisProperties`:
```java
	@bean(autowireCandidate = false) // do not back off autoconfigured one
	@ConfigurationProperties(prefix = "additional.data.redis", inheritedPrefix = "spring.data.redis")
	RedisProperties additionalRedisProperties() {
		return new RedisProperties();
	}
```

Author: quaff

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/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesTests.java

@@ -128,6 +128,7 @@
  * @author Stephane Nicoll
  * @author Madhura Bhave
  * @author Vladislav Kisel
+ * @author Yanming Zhou
  */
 @ExtendWith(OutputCaptureExtension.class)
 class ConfigurationPropertiesTests {
@@ -1270,6 +1271,15 @@ void loadWhenBindingToJavaBeanWithConversionToCustomListImplementation() {
 		assertThat(this.context.getBean(SetterBoundCustomListProperties.class).getValues()).containsExactly("a", "b");
 	}
 
+	@Test
+	void bindMultipleBeansUsingInheritedPrefix() {
+		load(InheritedPrefixConfiguration.class, "spring.service.host=127.0.0.1", "spring.service.port=6379",
+				"additional.service.port=6380");
+		ServiceProperties properties = this.context.getBean("additionalServiceProperties", ServiceProperties.class);
+		assertThat(properties.getHost()).isEqualTo("127.0.0.1");
+		assertThat(properties.getPort()).isEqualTo(6380);
+	}
+
 	private AnnotationConfigApplicationContext load(Class<?> configuration, String... inlinedProperties) {
 		return load(new Class<?>[] { configuration }, inlinedProperties);
 	}
@@ -3310,4 +3320,40 @@ static final class CustomList<E> extends ArrayList<E> {
 
 	}
 
+	@ConfigurationProperties(prefix = "spring.service")
+	static class ServiceProperties {
+
+		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(ServiceProperties.class)
+	static class InheritedPrefixConfiguration {
+
+		@Bean(autowireCandidate = false) // do not back off auto-configured one
+		@ConfigurationProperties(prefix = "additional.service", inheritedPrefix = "spring.service")
+		ServiceProperties additionalServiceProperties() {
+			return new ServiceProperties();
+		}
+
+	}
+
 }