Merge pull request #47802 from Asanio06

* pr/47802:
  Polish contribution
  Add support for configuring additional PersistenceUnitPostProcessor

Closes gh-47802

module/spring-boot-hibernate/src/test/java/org/springframework/boot/hibernate/autoconfigure/HibernateJpaAutoConfigurationTests.java

@@ -351,6 +351,19 @@ class HibernateJpaAutoConfigurationTests {
 			});
 	}
 
+	@Test
+	void customPersistenceUnitProcessorsAddedByServeralContributors() {
+		this.contextRunner.withUserConfiguration(TestConfigurationWithMultipleCustomPersistenceUnitPostProcessors.class)
+			.run((context) -> {
+				LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = context
+					.getBean(LocalContainerEntityManagerFactoryBean.class);
+				PersistenceUnitInfo persistenceUnitInfo = entityManagerFactoryBean.getPersistenceUnitInfo();
+				assertThat(persistenceUnitInfo).isNotNull();
+				assertThat(persistenceUnitInfo.getManagedClassNames()).contains(
+						"customized.attribute.converter.class.name", "customized.attribute.converter.class.anotherName");
+			});
+	}
+
 	@Test
 	void customManagedClassNameFilter() {
 		this.contextRunner.withBean(ManagedClassNameFilter.class, () -> (s) -> !s.endsWith("City"))
@@ -1168,6 +1181,24 @@ class HibernateJpaAutoConfigurationTests {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	@TestAutoConfigurationPackage(HibernateJpaAutoConfigurationTests.class)
+	static class TestConfigurationWithMultipleCustomPersistenceUnitPostProcessors {
+
+		@Bean
+		EntityManagerFactoryBuilderCustomizer entityManagerFactoryBuilderCustomizer() {
+			return (builder) -> builder.addPersistenceUnitPostProcessors(
+					(pui) -> pui.addManagedClassName("customized.attribute.converter.class.name"));
+		}
+
+		@Bean
+		EntityManagerFactoryBuilderCustomizer anotherEntityManagerFactoryBuilderCustomizer() {
+			return (builder) -> builder.addPersistenceUnitPostProcessors(
+					(pui) -> pui.addManagedClassName("customized.attribute.converter.class.anotherName"));
+		}
+
+	}
+
 	static class CustomJpaTransactionManager extends JpaTransactionManager {
 
 	}

module/spring-boot-jpa/build.gradle

@@ -36,7 +36,6 @@ dependencies {
 	testImplementation(project(":core:spring-boot-test"))
 	testImplementation(project(":test-support:spring-boot-test-support"))
 	testImplementation(testFixtures(project(":core:spring-boot-autoconfigure")))
-	testImplementation("org.springframework:spring-context-support")
 }
 
 tasks.named("compileTestJava") {

module/spring-boot-jpa/src/main/java/org/springframework/boot/jpa/EntityManagerFactoryBuilder.java

@@ -17,9 +17,12 @@
 package org.springframework.boot.jpa;
 
 import java.net.URL;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Function;
@@ -63,7 +66,7 @@ public class EntityManagerFactoryBuilder {
 
 	private @Nullable AsyncTaskExecutor bootstrapExecutor;
 
-	private PersistenceUnitPostProcessor @Nullable [] persistenceUnitPostProcessors;
+	private @Nullable List<PersistenceUnitPostProcessor> persistenceUnitPostProcessors;
 
 	/**
 	 * Create a new instance passing in the common pieces that will be shared if multiple
@@ -126,7 +129,23 @@ public class EntityManagerFactoryBuilder {
 	 * @param persistenceUnitPostProcessors the persistence unit post processors to use
 	 */
 	public void setPersistenceUnitPostProcessors(PersistenceUnitPostProcessor... persistenceUnitPostProcessors) {
-		this.persistenceUnitPostProcessors = persistenceUnitPostProcessors;
+		this.persistenceUnitPostProcessors = new ArrayList<>(Arrays.asList(persistenceUnitPostProcessors));
+	}
+
+	/**
+	 * Add {@linkplain PersistenceUnitPostProcessor persistence unit post processors} to
+	 * be applied to the PersistenceUnitInfo used for creating the
+	 * {@link LocalContainerEntityManagerFactoryBean}.
+	 * @param persistenceUnitPostProcessors the persistence unit post processors to add
+	 * @since 4.1.0
+	 */
+	public void addPersistenceUnitPostProcessors(PersistenceUnitPostProcessor... persistenceUnitPostProcessors) {
+		if (this.persistenceUnitPostProcessors != null) {
+			this.persistenceUnitPostProcessors.addAll(Arrays.asList(persistenceUnitPostProcessors));
+		}
+		else {
+			setPersistenceUnitPostProcessors(persistenceUnitPostProcessors);
+		}
 	}
 
 	/**
@@ -280,7 +299,8 @@ public class EntityManagerFactoryBuilder {
 			}
 			if (EntityManagerFactoryBuilder.this.persistenceUnitPostProcessors != null) {
 				entityManagerFactoryBean
-					.setPersistenceUnitPostProcessors(EntityManagerFactoryBuilder.this.persistenceUnitPostProcessors);
+					.setPersistenceUnitPostProcessors(EntityManagerFactoryBuilder.this.persistenceUnitPostProcessors
+						.toArray(PersistenceUnitPostProcessor[]::new));
 			}
 			return entityManagerFactoryBean;
 		}

module/spring-boot-jpa/src/test/java/org/springframework/boot/jpa/EntityManagerFactoryBuilderTests.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2012-present 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.jpa;
+
+import java.util.Collections;
+import java.util.Map;
+import java.util.function.Function;
+
+import javax.sql.DataSource;
+
+import jakarta.persistence.spi.PersistenceProvider;
+import org.assertj.core.api.InstanceOfAssertFactories;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.orm.jpa.persistenceunit.PersistenceUnitPostProcessor;
+import org.springframework.orm.jpa.vendor.AbstractJpaVendorAdapter;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link EntityManagerFactoryBuilder}.
+ *
+ * @author Stephane Nicoll
+ */
+class EntityManagerFactoryBuilderTests {
+
+	@Test
+	void setPersistenceUnitPostProcessorsWhenEmpty() {
+		EntityManagerFactoryBuilder builder = createEmptyBuilder();
+		PersistenceUnitPostProcessor postProcessor = mock();
+		PersistenceUnitPostProcessor postProcessor2 = mock();
+		builder.setPersistenceUnitPostProcessors(postProcessor, postProcessor2);
+		assertThat(builder).extracting("persistenceUnitPostProcessors")
+			.asInstanceOf(InstanceOfAssertFactories.LIST)
+			.containsExactly(postProcessor, postProcessor2);
+	}
+
+	@Test
+	void addPersistenceUnitPostProcessorsWhenEmpty() {
+		EntityManagerFactoryBuilder builder = createEmptyBuilder();
+		PersistenceUnitPostProcessor postProcessor = mock();
+		PersistenceUnitPostProcessor postProcessor2 = mock();
+		builder.addPersistenceUnitPostProcessors(postProcessor, postProcessor2);
+		assertThat(builder).extracting("persistenceUnitPostProcessors")
+				.asInstanceOf(InstanceOfAssertFactories.LIST)
+				.containsExactly(postProcessor, postProcessor2);
+	}
+
+	@Test
+	void setPersistenceUnitPostProcessorsWhenNotEmpty() {
+		EntityManagerFactoryBuilder builder = createEmptyBuilder();
+		PersistenceUnitPostProcessor postProcessor = mock();
+		builder.addPersistenceUnitPostProcessors(postProcessor);
+		PersistenceUnitPostProcessor postProcessor2 = mock();
+		PersistenceUnitPostProcessor postProcessor3 = mock();
+		builder.setPersistenceUnitPostProcessors(postProcessor2, postProcessor3);
+		assertThat(builder).extracting("persistenceUnitPostProcessors")
+				.asInstanceOf(InstanceOfAssertFactories.LIST)
+				.containsExactly(postProcessor2, postProcessor3);
+	}
+
+	@Test
+	void addPersistenceUnitPostProcessorsWhenNotEmpty() {
+		EntityManagerFactoryBuilder builder = createEmptyBuilder();
+		PersistenceUnitPostProcessor postProcessor = mock();
+		builder.addPersistenceUnitPostProcessors(postProcessor);
+		PersistenceUnitPostProcessor postProcessor2 = mock();
+		builder.addPersistenceUnitPostProcessors(postProcessor2);
+		assertThat(builder).extracting("persistenceUnitPostProcessors")
+				.asInstanceOf(InstanceOfAssertFactories.LIST)
+				.containsExactly(postProcessor, postProcessor2);
+	}
+
+	private EntityManagerFactoryBuilder createEmptyBuilder() {
+		Function<DataSource, Map<String, ?>> jpaPropertiesFactory = (dataSource) -> Collections
+				.emptyMap();
+		return new EntityManagerFactoryBuilder(new TestJpaVendorAdapter(), jpaPropertiesFactory, null);
+	}
+
+	static class TestJpaVendorAdapter extends AbstractJpaVendorAdapter {
+
+		@Override
+		public PersistenceProvider getPersistenceProvider() {
+			return mock();
+		}
+
+	}
+
+}