Align with breaking changes in latest Batch snapshots

Batch is now auto-configured to use the context's
PlatformTransactionManager and DataSource or `@BatchDataSource`.
When this does not meet the user's needs, they can use
`@EnableBatchProcessing` or sub-class `DefaultBatchConfiguration` to
take complete control with the auto-configuration backing off.

Closes gh-32330

Author: wilkinsona

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/batch/BasicBatchConfigurer.java

@@ -19,6 +19,8 @@
 import javax.sql.DataSource;
 
 import org.springframework.batch.core.configuration.ListableJobLocator;
+import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
+import org.springframework.batch.core.configuration.support.DefaultBatchConfiguration;
 import org.springframework.batch.core.converter.JobParametersConverter;
 import org.springframework.batch.core.explore.JobExplorer;
 import org.springframework.batch.core.launch.JobLauncher;
@@ -35,13 +37,16 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
 import org.springframework.boot.autoconfigure.sql.init.OnDatabaseInitializationCondition;
+import org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.sql.init.dependency.DatabaseInitializationDependencyConfigurer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 import org.springframework.jdbc.datasource.init.DatabasePopulator;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.Isolation;
 import org.springframework.util.StringUtils;
 
 /**
@@ -60,11 +65,12 @@
  * @author Mahmoud Ben Hassine
  * @since 1.0.0
  */
-@AutoConfiguration(after = HibernateJpaAutoConfiguration.class)
+@AutoConfiguration(after = { HibernateJpaAutoConfiguration.class, TransactionAutoConfiguration.class })
 @ConditionalOnClass({ JobLauncher.class, DataSource.class, DatabasePopulator.class })
-@ConditionalOnBean({ DataSource.class, JobLauncher.class })
+@ConditionalOnBean({ DataSource.class, PlatformTransactionManager.class })
+@ConditionalOnMissingBean(value = DefaultBatchConfiguration.class, annotation = EnableBatchProcessing.class)
 @EnableConfigurationProperties(BatchProperties.class)
-@Import({ BatchConfigurerConfiguration.class, DatabaseInitializationDependencyConfigurer.class })
+@Import(DatabaseInitializationDependencyConfigurer.class)
 public class BatchAutoConfiguration {
 
 	@Bean
@@ -100,6 +106,46 @@ public SimpleJobOperator jobOperator(ObjectProvider<JobParametersConverter> jobP
 		return factory;
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class SpringBootBatchConfiguration extends DefaultBatchConfiguration {
+
+		private final DataSource dataSource;
+
+		private final PlatformTransactionManager transactionManager;
+
+		private final BatchProperties properties;
+
+		SpringBootBatchConfiguration(DataSource dataSource, @BatchDataSource ObjectProvider<DataSource> batchDataSource,
+				PlatformTransactionManager transactionManager, BatchProperties properties) {
+			this.dataSource = batchDataSource.getIfAvailable(() -> dataSource);
+			this.transactionManager = transactionManager;
+			this.properties = properties;
+		}
+
+		@Override
+		protected DataSource getDataSource() {
+			return this.dataSource;
+		}
+
+		@Override
+		protected PlatformTransactionManager getTransactionManager() {
+			return this.transactionManager;
+		}
+
+		@Override
+		protected String getTablePrefix() {
+			String tablePrefix = this.properties.getJdbc().getTablePrefix();
+			return (tablePrefix != null) ? tablePrefix : super.getTablePrefix();
+		}
+
+		@Override
+		protected Isolation getIsolationLevelForCreate() {
+			Isolation isolation = this.properties.getJdbc().getIsolationLevelForCreate();
+			return (isolation != null) ? isolation : super.getIsolationLevelForCreate();
+		}
+
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	@Conditional(OnBatchDatasourceInitializationCondition.class)
 	static class DataSourceInitializerConfiguration {

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/batch/BatchAutoConfiguration.java

@@ -18,6 +18,7 @@
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.sql.init.DatabaseInitializationMode;
+import org.springframework.transaction.annotation.Isolation;
 
 /**
  * Configuration properties for Spring Batch.
@@ -135,45 +136,4 @@ public void setInitializeSchema(DatabaseInitializationMode initializeSchema) {
 
 	}
 
-	/**
-	 * Available transaction isolation levels.
-	 */
-	public enum Isolation {
-
-		/**
-		 * Use the default isolation level of the underlying datastore.
-		 */
-		DEFAULT,
-
-		/**
-		 * Indicates that dirty reads, non-repeatable reads and phantom reads can occur.
-		 */
-		READ_UNCOMMITTED,
-
-		/**
-		 * Indicates that dirty reads are prevented; non-repeatable reads and phantom
-		 * reads can occur.
-		 */
-		READ_COMMITTED,
-
-		/**
-		 * Indicates that dirty reads and non-repeatable reads are prevented; phantom
-		 * reads can occur.
-		 */
-		REPEATABLE_READ,
-
-		/**
-		 * Indicate that dirty reads, non-repeatable reads and phantom reads are
-		 * prevented.
-		 */
-		SERIALIZABLE;
-
-		private static final String PREFIX = "ISOLATION_";
-
-		String toIsolationName() {
-			return PREFIX + name();
-		}
-
-	}
-
 }