Make MapJobRegistry smart to auto register jobs at startup

Before this commit, it was required to populate the job registry
with a different component (like a bean post processor or a smart
initializing singleton) before being able to use it with the JobOperator.

This commit makes the `MapJobRegistry` smart enough to auto register
jobs defined in the application context. This removes the need for a
distinct component to populate the registry and therefore simplifies
the configuration.

This commit also:

- removes the usage of `JobFactory` from `JobRegistry`
- deprecates JobRegistrySmartInitializingSingleton and removes
its configuration from the default batch configuration

Resolves #4854
Resolves #4855
Resolves #4856

Author: fmbenhassine

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2025 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.
@@ -22,17 +22,18 @@
  * <code>name</code>.
  *
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 public interface JobRegistry extends ListableJobLocator {
 
 	/**
 	 * Registers a {@link Job} at runtime.
-	 * @param jobFactory the {@link Job} to be registered
-	 * @throws DuplicateJobException if a factory with the same job name has already been
+	 * @param job the {@link Job} to be registered
+	 * @throws DuplicateJobException if a job with the same name has already been
 	 * registered.
 	 */
-	void register(JobFactory jobFactory) throws DuplicateJobException;
+	void register(Job job) throws DuplicateJobException;
 
 	/**
 	 * Unregisters a previously registered {@link Job}. If it was not previously

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/annotation/BatchRegistrar.java

@@ -22,7 +22,6 @@
 
 import org.springframework.batch.core.configuration.support.AutomaticJobRegistrar;
 import org.springframework.batch.core.configuration.support.DefaultJobLoader;
-import org.springframework.batch.core.configuration.support.JobRegistrySmartInitializingSingleton;
 import org.springframework.batch.core.configuration.support.MapJobRegistry;
 import org.springframework.batch.core.launch.support.JobOperatorFactoryBean;
 import org.springframework.batch.core.repository.support.JdbcJobRepositoryFactoryBean;
@@ -70,7 +69,6 @@ public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, B
 			.synthesize();
 		registerJobRepository(registry, importingClassMetadata);
 		registerJobRegistry(registry);
-		registerJobRegistrySmartInitializingSingleton(registry);
 		registerJobOperator(registry, batchAnnotation);
 		registerAutomaticJobRegistrar(registry, batchAnnotation);
 		watch.stop();
@@ -220,21 +218,6 @@ private void registerJobRegistry(BeanDefinitionRegistry registry) {
 		registry.registerBeanDefinition(JOB_REGISTRY, beanDefinition);
 	}
 
-	private void registerJobRegistrySmartInitializingSingleton(BeanDefinitionRegistry registry) {
-		if (registry.containsBeanDefinition("jobRegistrySmartInitializingSingleton")) {
-			LOGGER
-				.info("Bean jobRegistrySmartInitializingSingleton already defined in the application context, skipping"
-						+ " the registration of a jobRegistrySmartInitializingSingleton");
-			return;
-		}
-		BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder
-			.genericBeanDefinition(JobRegistrySmartInitializingSingleton.class);
-		beanDefinitionBuilder.addPropertyReference(JOB_REGISTRY, JOB_REGISTRY);
-
-		registry.registerBeanDefinition("jobRegistrySmartInitializingSingleton",
-				beanDefinitionBuilder.getBeanDefinition());
-	}
-
 	private void registerJobOperator(BeanDefinitionRegistry registry, EnableBatchProcessing batchAnnotation) {
 		if (registry.containsBeanDefinition(JOB_OPERATOR)) {
 			LOGGER.info("Bean jobOperator already defined in the application context, skipping"

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

@@ -50,8 +50,6 @@
  * <li>a {@link ResourcelessJobRepository} named "jobRepository"</li>
  * <li>a {@link MapJobRegistry} named "jobRegistry"</li>
  * <li>a {@link TaskExecutorJobOperator} named "JobOperator"</li>
- * <li>a {@link JobRegistrySmartInitializingSingleton} named
- * "jobRegistrySmartInitializingSingleton"</li>
  * <li>a {@link org.springframework.batch.core.scope.StepScope} named "stepScope"</li>
  * <li>a {@link org.springframework.batch.core.scope.JobScope} named "jobScope"</li>
  * </ul>
@@ -117,21 +115,6 @@ public JobOperator jobOperator(JobRepository jobRepository, JobRegistry jobRegis
 		}
 	}
 
-	@Bean
-	public JobRegistrySmartInitializingSingleton jobRegistrySmartInitializingSingleton(JobRegistry jobRegistry)
-			throws BatchConfigurationException {
-		JobRegistrySmartInitializingSingleton jobRegistrySmartInitializingSingleton = new JobRegistrySmartInitializingSingleton();
-		jobRegistrySmartInitializingSingleton.setJobRegistry(jobRegistry);
-		try {
-			jobRegistrySmartInitializingSingleton.afterPropertiesSet();
-			return jobRegistrySmartInitializingSingleton;
-		}
-		catch (Exception e) {
-			throw new BatchConfigurationException(
-					"Unable to configure the default job registry SmartInitializingSingleton", e);
-		}
-	}
-
 	/**
 	 * Return the transaction manager to use for the job operator. Defaults to
 	 * {@link ResourcelessTransactionManager}.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2023 the original author or authors.
+ * Copyright 2006-2025 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.
@@ -27,7 +27,6 @@
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.Step;
 import org.springframework.batch.core.configuration.DuplicateJobException;
-import org.springframework.batch.core.configuration.JobFactory;
 import org.springframework.batch.core.configuration.JobRegistry;
 import org.springframework.batch.core.configuration.StepRegistry;
 import org.springframework.batch.core.launch.NoSuchJobException;
@@ -251,8 +250,7 @@ private Collection<Step> getSteps(final StepLocator stepLocator, final Applicati
 	 * @throws DuplicateJobException if that job is already registered
 	 */
 	private void doRegister(ConfigurableApplicationContext context, Job job) throws DuplicateJobException {
-		final JobFactory jobFactory = new ReferenceJobFactory(job);
-		jobRegistry.register(jobFactory);
+		jobRegistry.register(job);
 
 		if (stepRegistry != null) {
 			if (!(job instanceof StepLocator)) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2023 the original author or authors.
+ * Copyright 2006-2025 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.
@@ -27,6 +27,7 @@
  * Generic service that can bind and unbind a {@link JobFactory} in a {@link JobRegistry}.
  *
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 public class JobFactoryRegistrationListener {
@@ -53,7 +54,7 @@ public void bind(JobFactory jobFactory, Map<String, ?> params) throws Exception
 		if (logger.isInfoEnabled()) {
 			logger.info("Binding JobFactory: " + jobFactory.getJobName());
 		}
-		jobRegistry.register(jobFactory);
+		jobRegistry.register(jobFactory.createJob());
 	}
 
 	/**

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

@@ -45,7 +45,10 @@
  *
  * @author Henning Pöttker
  * @since 5.1.1
+ * @deprecated since 6.0 with no replacement. Register a {@link MapJobRegistry} as a bean,
+ * and it will automatically register all {@link Job} beans in the application context.
  */
+@Deprecated(since = "6.0", forRemoval = true)
 public class JobRegistrySmartInitializingSingleton
 		implements SmartInitializingSingleton, BeanFactoryAware, InitializingBean, DisposableBean {
 
@@ -143,12 +146,11 @@ private void postProcessAfterInitialization(Job job, String beanName) {
 				groupName = getGroupName(defaultListableBeanFactory.getBeanDefinition(beanName), job);
 			}
 			job = groupName == null ? job : new GroupAwareJob(groupName, job);
-			ReferenceJobFactory jobFactory = new ReferenceJobFactory(job);
-			String name = jobFactory.getJobName();
+			String name = job.getName();
 			if (logger.isDebugEnabled()) {
 				logger.debug("Registering job: " + name);
 			}
-			jobRegistry.register(jobFactory);
+			jobRegistry.register(job);
 			jobNames.add(name);
 		}
 		catch (DuplicateJobException e) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2019 the original author or authors.
+ * Copyright 2006-2025 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.
@@ -16,68 +16,89 @@
 package org.springframework.batch.core.configuration.support;
 
 import java.util.Collections;
+import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.configuration.DuplicateJobException;
-import org.springframework.batch.core.configuration.JobFactory;
 import org.springframework.batch.core.configuration.JobRegistry;
 import org.springframework.batch.core.launch.NoSuchJobException;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.SmartInitializingSingleton;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
- * Simple, thread-safe, map-based implementation of {@link JobRegistry}.
+ * Simple, thread-safe, map-based implementation of {@link JobRegistry}. This registry is
+ * a {@link SmartInitializingSingleton} that is automatically populated with all
+ * {@link Job} beans in the {@link ApplicationContext}.
  *
  * @author Dave Syer
  * @author Robert Fischer
  * @author Mahmoud Ben Hassine
  */
-public class MapJobRegistry implements JobRegistry {
+public class MapJobRegistry implements JobRegistry, SmartInitializingSingleton, ApplicationContextAware {
+
+	protected final Log logger = LogFactory.getLog(getClass());
 
 	/**
-	 * The map holding the registered job factories.
+	 * The map holding the registered jobs.
 	 */
-	// The "final" ensures that it is visible and initialized when the constructor
-	// resolves.
-	private final ConcurrentMap<String, JobFactory> map = new ConcurrentHashMap<>();
+	private final ConcurrentMap<String, Job> map = new ConcurrentHashMap<>();
+
+	private ApplicationContext applicationContext;
+
+	@Override
+	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+		this.applicationContext = applicationContext;
+	}
+
+	@Override
+	public void afterSingletonsInstantiated() {
+		Map<String, Job> jobBeans = this.applicationContext.getBeansOfType(Job.class);
+		this.map.putAll(jobBeans);
+	}
 
 	@Override
-	public void register(JobFactory jobFactory) throws DuplicateJobException {
-		Assert.notNull(jobFactory, "jobFactory is null");
-		String name = jobFactory.getJobName();
-		Assert.notNull(name, "Job configuration must have a name.");
-		JobFactory previousValue = map.putIfAbsent(name, jobFactory);
+	public void register(Job job) throws DuplicateJobException {
+		Assert.notNull(job, "job must not be null");
+		String jobName = job.getName();
+		Assert.notNull(jobName, "Job name must not be null");
+		Job previousValue = this.map.putIfAbsent(jobName, job);
 		if (previousValue != null) {
-			throw new DuplicateJobException("A job configuration with this name [" + name + "] was already registered");
+			throw new DuplicateJobException("A job with this name [" + jobName + "] was already registered");
 		}
 	}
 
 	@Override
 	public void unregister(String name) {
-		Assert.notNull(name, "Job configuration must have a name.");
-		map.remove(name);
+		Assert.notNull(name, "Job name must not be null");
+		this.map.remove(name);
 	}
 
 	@Override
 	public Job getJob(@Nullable String name) throws NoSuchJobException {
-		JobFactory factory = map.get(name);
-		if (factory == null) {
-			throw new NoSuchJobException("No job configuration with the name [" + name + "] was registered");
+		Job job = this.map.get(name);
+		if (job == null) {
+			throw new NoSuchJobException("No job with the name [" + name + "] was registered");
 		}
 		else {
-			return factory.createJob();
+			return job;
 		}
 	}
 
 	/**
-	 * Provides an unmodifiable view of the job names.
+	 * Provides an unmodifiable view of job names.
 	 */
 	@Override
 	public Set<String> getJobNames() {
-		return Collections.unmodifiableSet(map.keySet());
+		return Collections.unmodifiableSet(this.map.keySet());
 	}
 
 }

spring-batch-core/src/test/java/org/springframework/batch/core/configuration/annotation/BatchRegistrarTests.java

@@ -27,7 +27,6 @@
 import org.springframework.batch.core.DefaultJobKeyGenerator;
 import org.springframework.batch.core.JobKeyGenerator;
 import org.springframework.batch.core.configuration.JobRegistry;
-import org.springframework.batch.core.configuration.support.JobRegistrySmartInitializingSingleton;
 import org.springframework.batch.core.converter.DefaultJobParametersConverter;
 import org.springframework.batch.core.converter.JobParametersConverter;
 import org.springframework.batch.core.converter.JsonJobParametersConverter;
@@ -64,8 +63,6 @@ void testConfigurationWithUserDefinedBeans() {
 		Assertions.assertTrue(Mockito.mockingDetails(context.getBean(JobRepository.class)).isMock());
 		Assertions.assertTrue(Mockito.mockingDetails(context.getBean(JobRegistry.class)).isMock());
 		Assertions.assertTrue(Mockito.mockingDetails(context.getBean(JobOperator.class)).isMock());
-		Assertions
-			.assertTrue(Mockito.mockingDetails(context.getBean(JobRegistrySmartInitializingSingleton.class)).isMock());
 	}
 
 	@Test
@@ -147,15 +144,12 @@ void testDefaultInfrastructureBeansRegistration() {
 		JobRepository jobRepository = context.getBean(JobRepository.class);
 		JobRegistry jobRegistry = context.getBean(JobRegistry.class);
 		JobOperator jobOperator = context.getBean(JobOperator.class);
-		JobRegistrySmartInitializingSingleton jobRegistrySmartInitializingSingleton = context
-			.getBean(JobRegistrySmartInitializingSingleton.class);
 
 		// then
 		Assertions.assertNotNull(jobLauncher);
 		Assertions.assertNotNull(jobRepository);
 		Assertions.assertNotNull(jobRegistry);
 		Assertions.assertNotNull(jobOperator);
-		Assertions.assertNotNull(jobRegistrySmartInitializingSingleton);
 	}
 
 	@Test
@@ -236,11 +230,6 @@ public JobOperator jobOperator() {
 			return Mockito.mock();
 		}
 
-		@Bean
-		public JobRegistrySmartInitializingSingleton jobRegistrySmartInitializingSingleton() {
-			return Mockito.mock();
-		}
-
 	}
 
 	@Configuration

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022-2024 the original author or authors.
+ * Copyright 2022-2025 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.
@@ -36,7 +36,6 @@
 import org.springframework.batch.core.step.builder.StepBuilder;
 import org.springframework.batch.core.step.tasklet.Tasklet;
 import org.springframework.batch.repeat.RepeatStatus;
-import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -72,9 +71,6 @@ void testConfigurationWithCustomInfrastructureBean() {
 		Assertions.assertEquals(1, jobRepositories.size());
 		JobRepository jobRepository = jobRepositories.entrySet().iterator().next().getValue();
 		Assertions.assertInstanceOf(DummyJobRepository.class, jobRepository);
-		Map<String, JobRegistrySmartInitializingSingleton> jobRegistrySmartInitializingSingletonMap = context
-			.getBeansOfType(JobRegistrySmartInitializingSingleton.class);
-		Assertions.assertEquals(1, jobRegistrySmartInitializingSingletonMap.size());
 	}
 
 	@Test
@@ -87,15 +83,12 @@ void testDefaultInfrastructureBeansRegistration() {
 		JobRepository jobRepository = context.getBean(JobRepository.class);
 		JobRegistry jobRegistry = context.getBean(JobRegistry.class);
 		JobOperator jobOperator = context.getBean(JobOperator.class);
-		JobRegistrySmartInitializingSingleton jobRegistrySmartInitializingSingleton = context
-			.getBean(JobRegistrySmartInitializingSingleton.class);
 
 		// then
 		Assertions.assertNotNull(jobLauncher);
 		Assertions.assertNotNull(jobRepository);
 		Assertions.assertNotNull(jobRegistry);
 		Assertions.assertNotNull(jobOperator);
-		Assertions.assertNotNull(jobRegistrySmartInitializingSingleton);
 	}
 
 	@Configuration
@@ -136,13 +129,6 @@ public JobRepository jobRepository() {
 			return new DummyJobRepository();
 		}
 
-		@Bean
-		public JobRegistrySmartInitializingSingleton jobRegistrySmartInitializingSingleton(JobRegistry jobRegistry) {
-			JobRegistrySmartInitializingSingleton smartInitializingSingleton = new JobRegistrySmartInitializingSingleton();
-			smartInitializingSingleton.setJobRegistry(jobRegistry);
-			return smartInitializingSingleton;
-		}
-
 	}
 
 }