Add support for in-memory Batch infrastructure

This commit moves the existing JDBC-based Spring Batch infrastructure
to a new 'spring-boot-batch-jdbc' module, while the existing module
only offers in-memory (aka resourceless) support.

The commit also updates the reference guide to provide some more
information about what's available and how to use it.

Closes gh-46307

Author: snicoll

documentation/spring-boot-docs/src/docs/antora/modules/ROOT/pages/redirect.adoc

@@ -387,8 +387,6 @@
 * xref:how-to:batch.adoc#howto.batch.restarting-a-failed-job[#howto.batch.restarting-a-failed-job]
 * xref:how-to:batch.adoc#howto.batch.running-from-the-command-line[#howto-spring-batch-running-command-line]
 * xref:how-to:batch.adoc#howto.batch.running-from-the-command-line[#howto.batch.running-from-the-command-line]
-* xref:how-to:batch.adoc#howto.batch.running-jobs-on-startup[#howto-spring-batch-running-jobs-on-startup]
-* xref:how-to:batch.adoc#howto.batch.running-jobs-on-startup[#howto.batch.running-jobs-on-startup]
 * xref:how-to:batch.adoc#howto.batch.specifying-a-data-source[#howto-spring-batch-specifying-a-data-source]
 * xref:how-to:batch.adoc#howto.batch.specifying-a-data-source[#howto.batch.specifying-a-data-source]
 * xref:how-to:batch.adoc#howto.batch.specifying-a-transaction-manager[#howto.batch.specifying-a-transaction-manager]
@@ -1633,6 +1631,8 @@
 * xref:reference:features/ssl.adoc#features.ssl[#features.ssl]
 * xref:reference:features/task-execution-and-scheduling.adoc#features.task-execution-and-scheduling[#boot-features-task-execution-scheduling]
 * xref:reference:features/task-execution-and-scheduling.adoc#features.task-execution-and-scheduling[#features.task-execution-and-scheduling]
+* xref:reference:io/spring-batch.adoc#io.spring-batch.running-jobs-on-startup[#howto-spring-batch-running-jobs-on-startup]
+* xref:reference:io/spring-batch.adoc#io.spring-batch.running-jobs-on-startup[#howto.batch.running-jobs-on-startup]
 * xref:reference:io/caching.adoc#io.caching.provider.cache2k[#io.caching.provider.cache2k]
 * xref:reference:io/caching.adoc#io.caching.provider.caffeine[#boot-features-caching-provider-caffeine]
 * xref:reference:io/caching.adoc#io.caching.provider.caffeine[#features.caching.provider.caffeine]

documentation/spring-boot-docs/src/docs/antora/modules/how-to/pages/batch.adoc

@@ -37,20 +37,6 @@ If you do so and want two task executors (for example by retaining the auto-conf
 
 
 
-[[howto.batch.running-jobs-on-startup]]
-== Running Spring Batch Jobs on Startup
-
-Spring Batch auto-configuration is enabled by adding `spring-boot-starter-batch` to your application's classpath.
-
-If a single javadoc:org.springframework.batch.core.Job[] bean is found in the application context, it is executed on startup (see javadoc:org.springframework.boot.autoconfigure.batch.JobLauncherApplicationRunner[] for details).
-If multiple javadoc:org.springframework.batch.core.Job[] beans are found, the job that should be executed must be specified using configprop:spring.batch.job.name[].
-
-To disable running a javadoc:org.springframework.batch.core.Job[] found in the application context, set the configprop:spring.batch.job.enabled[] to `false`.
-
-See {code-spring-boot-autoconfigure-src}/batch/BatchAutoConfiguration.java[`BatchAutoConfiguration`] for more details.
-
-
-
 [[howto.batch.running-from-the-command-line]]
 == Running From the Command Line
 

documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/io/index.adoc

@@ -3,6 +3,6 @@
 
 Most applications will need to deal with input and output concerns at some point.
 Spring Boot provides utilities and integrations with a range of technologies to help when you need IO capabilities.
-This section covers standard IO features such as caching and validation as well as more advanced topics such as scheduling and distributed transactions.
+This section covers standard IO features such as caching and validation as well as more advanced topics such as batch, scheduling, and distributed transactions.
 We will also cover calling remote REST or SOAP services and sending email.
 

documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/io/spring-batch.adoc

@@ -0,0 +1,47 @@
+[[io.spring-batch]]
+= Spring Batch
+
+Spring Boot offers several conveniences for working with {url-spring-batch-site}[Spring Batch], including running a Job on startup.
+
+If Spring Batch is available on your classpath, it is initialized through the javadoc:org.springframework.batch.core.configuration.annotation.EnableBatchProcessing[format=annotation] annotation.
+
+When building a batch application, the following stores can be auto-configured:
+
+* In-memory
+* JDBC
+
+Each store has specific additional settings.
+For instance, it is possible to customize the tables prefix for the JDBC store, as shown in the following example:
+
+[configprops,yaml]
+----
+spring:
+  batch:
+    jdbc:
+      table-prefix: "CUSTOM_"
+----
+
+You can take control over Spring Batch's configuration using javadoc:org.springframework.batch.core.configuration.annotation.EnableBatchProcessing[format=annotation].
+This will cause the auto-configuration to back off.
+Spring Batch can then be configured using the `@Enable*JobRepository` annotation's attributes rather than the previously described configuration properties.
+
+
+
+[[io.spring-batch.running-jobs-on-startup]]
+== Running Spring Batch Jobs on Startup
+
+When Spring Boot auto-configures Spring Batch, and if a single javadoc:org.springframework.batch.core.Job[] bean is found in the application context, it is executed on startup (see javadoc:org.springframework.boot.autoconfigure.batch.JobLauncherApplicationRunner[] for details).
+If multiple javadoc:org.springframework.batch.core.Job[] beans are found, the job that should be executed must be specified using configprop:spring.batch.job.name[].
+
+You can disable running a javadoc:org.springframework.batch.core.Job[] found in the application context, as shown in the following example:
+
+[configprops,yaml]
+----
+spring:
+  batch:
+    job:
+      enabled: false
+----
+
+
+See javadoc:org.springframework.boot.batch.autoconfigure.BatchAutoConfiguration[] and javadoc:org.springframework.boot.batch.jdbc.autoconfigure.BatchJdbcAutoConfiguration[] for more details.

documentation/spring-boot-docs/src/docs/antora/modules/reference/partials/nav-reference.adoc

@@ -39,6 +39,7 @@
 
 ** xref:reference:io/index.adoc[]
 *** xref:reference:io/caching.adoc[]
+*** xref:reference:io/spring-batch.adoc[]
 *** xref:reference:io/hazelcast.adoc[]
 *** xref:reference:io/quartz.adoc[]
 *** xref:reference:io/email.adoc[]

module/spring-boot-batch-jdbc/build.gradle

@@ -0,0 +1,49 @@
+/*
+ * 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.
+ */
+
+plugins {
+	id "java-library"
+	id "org.springframework.boot.auto-configuration"
+	id "org.springframework.boot.configuration-properties"
+	id "org.springframework.boot.deployed"
+	id "org.springframework.boot.optional-dependencies"
+}
+
+description = "Spring Boot Batch JDBC"
+
+dependencies {
+	api(project(":module:spring-boot-batch"))
+	api(project(":module:spring-boot-jdbc"))
+
+	implementation(project(":module:spring-boot-tx"))
+
+	optional(project(":core:spring-boot-autoconfigure"))
+	optional(project(":module:spring-boot-hibernate"))
+	optional(project(":module:spring-boot-micrometer-observation"))
+
+	testImplementation(project(":core:spring-boot-test"))
+	testImplementation(project(":module:spring-boot-flyway"))
+	testImplementation(project(":module:spring-boot-liquibase"))
+	testImplementation(project(":test-support:spring-boot-test-support"))
+	testImplementation(testFixtures(project(":core:spring-boot-autoconfigure")))
+	testImplementation("io.micrometer:micrometer-observation-test")
+
+	testRuntimeOnly("ch.qos.logback:logback-classic")
+	testRuntimeOnly("com.fasterxml.jackson.core:jackson-databind")
+	testRuntimeOnly("com.fasterxml.jackson.datatype:jackson-datatype-jsr310")
+	testRuntimeOnly("com.h2database:h2")
+	testRuntimeOnly("com.zaxxer:HikariCP")
+}

module/spring-boot-batch/src/main/java/org/springframework/boot/batch/autoconfigure/BatchDataSource.java renamed to module/spring-boot-batch-jdbc/src/main/java/org/springframework/boot/batch/jdbc/autoconfigure/BatchDataSource.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.batch.autoconfigure;
+package org.springframework.boot.batch.jdbc.autoconfigure;
 
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;

module/spring-boot-batch/src/main/java/org/springframework/boot/batch/autoconfigure/BatchDataSourceScriptDatabaseInitializer.java renamed to module/spring-boot-batch-jdbc/src/main/java/org/springframework/boot/batch/jdbc/autoconfigure/BatchDataSourceScriptDatabaseInitializer.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.batch.autoconfigure;
+package org.springframework.boot.batch.jdbc.autoconfigure;
 
 import java.util.List;
 
@@ -43,7 +43,7 @@ public class BatchDataSourceScriptDatabaseInitializer extends DataSourceScriptDa
 	 * @param properties the Spring Batch JDBC properties
 	 * @see #getSettings
 	 */
-	public BatchDataSourceScriptDatabaseInitializer(DataSource dataSource, BatchProperties.Jdbc properties) {
+	public BatchDataSourceScriptDatabaseInitializer(DataSource dataSource, BatchJdbcProperties properties) {
 		this(dataSource, getSettings(dataSource, properties));
 	}
 
@@ -58,24 +58,23 @@ public BatchDataSourceScriptDatabaseInitializer(DataSource dataSource, DatabaseI
 	}
 
 	/**
-	 * Adapts {@link BatchProperties.Jdbc Spring Batch JDBC properties} to
-	 * {@link DatabaseInitializationSettings} replacing any {@literal @@platform@@}
-	 * placeholders.
+	 * Adapts {@link BatchJdbcProperties} to {@link DatabaseInitializationSettings}
+	 * replacing any {@literal @@platform@@} placeholders.
 	 * @param dataSource the Spring Batch data source
 	 * @param properties batch JDBC properties
 	 * @return a new {@link DatabaseInitializationSettings} instance
 	 * @see #BatchDataSourceScriptDatabaseInitializer(DataSource,
 	 * DatabaseInitializationSettings)
 	 */
-	public static DatabaseInitializationSettings getSettings(DataSource dataSource, BatchProperties.Jdbc properties) {
+	public static DatabaseInitializationSettings getSettings(DataSource dataSource, BatchJdbcProperties properties) {
 		DatabaseInitializationSettings settings = new DatabaseInitializationSettings();
 		settings.setSchemaLocations(resolveSchemaLocations(dataSource, properties));
 		settings.setMode(properties.getInitializeSchema());
 		settings.setContinueOnError(true);
 		return settings;
 	}
 
-	private static List<String> resolveSchemaLocations(DataSource dataSource, BatchProperties.Jdbc properties) {
+	private static List<String> resolveSchemaLocations(DataSource dataSource, BatchJdbcProperties properties) {
 		PlatformPlaceholderDatabaseDriverResolver platformResolver = new PlatformPlaceholderDatabaseDriverResolver();
 		if (StringUtils.hasText(properties.getPlatform())) {
 			return platformResolver.resolveAll(properties.getPlatform(), properties.getSchema());