Fix BeanPostProcessorChecker warnings

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/support/BatchBeanDefinitionRegistryPostProcessor.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2023 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.batch.core.configuration.support;
+
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
+
+public class BatchBeanDefinitionRegistryPostProcessor implements BeanDefinitionRegistryPostProcessor {
+
+	private static final String JOB_REGISTRY = "jobRegistry";
+
+	private static final String BEAN_POST_PROCESSOR = "jobRegistryBeanPostProcessor";
+
+	@Override
+	public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) {
+		if (!registry.containsBeanDefinition(JOB_REGISTRY)) {
+			var beanDefinition = BeanDefinitionBuilder.genericBeanDefinition(MapJobRegistry.class)
+				.setRole(BeanDefinition.ROLE_INFRASTRUCTURE)
+				.getBeanDefinition();
+			registry.registerBeanDefinition(JOB_REGISTRY, beanDefinition);
+		}
+
+		if (!registry.containsBeanDefinition(BEAN_POST_PROCESSOR)) {
+			var beanDefinition = BeanDefinitionBuilder.genericBeanDefinition(JobRegistryBeanPostProcessor.class)
+				.addPropertyReference(JOB_REGISTRY, JOB_REGISTRY)
+				.getBeanDefinition();
+			registry.registerBeanDefinition(BEAN_POST_PROCESSOR, beanDefinition);
+		}
+	}
+
+}

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/support/DefaultBatchConfiguration.java

@@ -112,13 +112,18 @@
  * @since 5.0
  */
 @Configuration(proxyBeanMethods = false)
-@Import(ScopeConfiguration.class)
+@Import({ ScopeConfiguration.class, BatchBeanDefinitionRegistryPostProcessor.class })
 public class DefaultBatchConfiguration implements ApplicationContextAware {
 
 	@Autowired
 	protected ApplicationContext applicationContext;
 
-	private final JobRegistry jobRegistry = new MapJobRegistry();
+	@Autowired
+	protected JobRegistry jobRegistry;
+
+	@Autowired
+	@Deprecated(forRemoval = true)
+	private JobRegistryBeanPostProcessor jobRegistryBeanPostProcessor;
 
 	@Override
 	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
@@ -187,9 +192,17 @@ public JobExplorer jobExplorer() throws BatchConfigurationException {
 		}
 	}
 
-	@Bean
+	/**
+	 * Defines a {@link JobRegistry} bean.
+	 * @return a {@link JobRegistry} bean
+	 * @throws BatchConfigurationException if unable to register the bean
+	 * @since 5.0
+	 * @deprecated in favor of bean injection, and declaring a custom bean with name
+	 * {@code jobRegistry}
+	 */
+	@Deprecated(forRemoval = true)
 	public JobRegistry jobRegistry() throws BatchConfigurationException {
-		return this.jobRegistry; // FIXME returning a new instance here does not work
+		return this.jobRegistry;
 	}
 
 	@Bean
@@ -214,18 +227,12 @@ public JobOperator jobOperator() throws BatchConfigurationException {
 	 * @return a {@link JobRegistryBeanPostProcessor} bean
 	 * @throws BatchConfigurationException if unable to register the bean
 	 * @since 5.1
+	 * @deprecated in favor of bean injection, and declaring a custom bean with name
+	 * {@code jobRegistryBeanPostProcessor}
 	 */
-	@Bean
+	@Deprecated(forRemoval = true)
 	public JobRegistryBeanPostProcessor jobRegistryBeanPostProcessor() throws BatchConfigurationException {
-		JobRegistryBeanPostProcessor jobRegistryBeanPostProcessor = new JobRegistryBeanPostProcessor();
-		jobRegistryBeanPostProcessor.setJobRegistry(jobRegistry());
-		try {
-			jobRegistryBeanPostProcessor.afterPropertiesSet();
-			return jobRegistryBeanPostProcessor;
-		}
-		catch (Exception e) {
-			throw new BatchConfigurationException("Unable to configure the default job registry BeanPostProcessor", e);
-		}
+		return this.jobRegistryBeanPostProcessor;
 	}
 
 	/*

spring-batch-core/src/test/java/org/springframework/batch/core/configuration/support/DefaultBatchConfigurationTests.java

@@ -160,7 +160,7 @@ public JobRepository jobRepository() {
 		}
 
 		@Bean
-		public JobRegistryBeanPostProcessor jobRegistryBeanPostProcessor(JobRegistry jobRegistry) {
+		public static JobRegistryBeanPostProcessor jobRegistryBeanPostProcessor(JobRegistry jobRegistry) {
 			JobRegistryBeanPostProcessor postProcessor = new JobRegistryBeanPostProcessor();
 			postProcessor.setJobRegistry(jobRegistry);
 			return postProcessor;