Add How-To documentation for ManagedClassNameFilter

This commit documents the support of ManagedClassNameFilter that was
added in gh-39813.

See gh-40617

Author: snicoll

spring-boot-project/spring-boot-docs/src/docs/antora/modules/how-to/pages/data-access.adoc

@@ -177,6 +177,17 @@ include-code::MyApplication[]
 
 
 
+[[howto.data-access.filter-scanned-entity-definitions]]
+== Filter scanned @Entity definitions
+
+It is possible to exclude some `@Entity` definitions using a `ManagedClassNameFilter` bean.
+This can be useful in tests when only a sub-set of the available entities should be considered.
+In the following example, only entities from the `com.example.app.customer` package are included:
+
+include-code::MyEntityScanConfiguration[]
+
+
+
 [[howto.data-access.jpa-properties]]
 == Configure JPA Properties
 

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/howto/dataaccess/filterscannedentitydefinitions/MyEntityScanConfiguration.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2012-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.howto.dataaccess.filterscannedentitydefinitions;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.orm.jpa.persistenceunit.ManagedClassNameFilter;
+
+@Configuration(proxyBeanMethods = false)
+public class MyEntityScanConfiguration {
+
+	@Bean
+	public ManagedClassNameFilter entityScanFilter() {
+		return (className) -> className.startsWith("com.example.app.customer");
+	}
+
+}

spring-boot-project/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/howto/dataaccess/filterscannedentitydefinitions/MyEntityScanConfiguration.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2012-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.howto.dataaccess.filterscannedentitydefinitions
+
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.orm.jpa.persistenceunit.ManagedClassNameFilter
+
+@Configuration(proxyBeanMethods = false)
+class MyEntityScanConfiguration {
+
+	@Bean
+	fun entityScanFilter() : ManagedClassNameFilter {
+		return ManagedClassNameFilter { className ->
+			className.startsWith("com.example.app.customer")
+		}
+	}
+}