Merge pull request #28859 from tiborsulyan

* pr/28859:
  Polish "Add option to allow Spring Batch custom isolation levels"
  Add option to allow Spring Batch custom isolation levels

Closes gh-28859

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -26,6 +26,7 @@ import org.springframework.batch.core.launch.support.SimpleJobLauncher;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.repository.support.JobRepositoryFactoryBean;
 import org.springframework.beans.factory.InitializingBean;
+import org.springframework.boot.autoconfigure.batch.BatchProperties.Isolation;
 import org.springframework.boot.autoconfigure.transaction.TransactionManagerCustomizers;
 import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.jdbc.datasource.DataSourceTransactionManager;
@@ -139,7 +140,8 @@ public class BasicBatchConfigurer implements BatchConfigurer, InitializingBean {
 	 * @return the isolation level or {@code null} to use the default
 	 */
 	protected String determineIsolationLevel() {
-		return null;
+		Isolation isolation = this.properties.getJdbc().getIsolationLevelForCreate();
+		return (isolation != null) ? isolation.toIsolationName() : null;
 	}
 
 	protected PlatformTransactionManager createTransactionManager() {

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

@@ -66,6 +66,12 @@ public class BatchProperties {
 		private static final String DEFAULT_SCHEMA_LOCATION = "classpath:org/springframework/"
 				+ "batch/core/schema-@@platform@@.sql";
 
+		/**
+		 * Transaction isolation level to use when creating job meta-data for new jobs.
+		 * Auto-detected based on whether JPA is being used or not.
+		 */
+		private Isolation isolationLevelForCreate;
+
 		/**
 		 * Path to the SQL file to use to initialize the database schema.
 		 */
@@ -87,6 +93,14 @@ public class BatchProperties {
 		 */
 		private DatabaseInitializationMode initializeSchema = DatabaseInitializationMode.EMBEDDED;
 
+		public Isolation getIsolationLevelForCreate() {
+			return this.isolationLevelForCreate;
+		}
+
+		public void setIsolationLevelForCreate(Isolation isolationLevelForCreate) {
+			this.isolationLevelForCreate = isolationLevelForCreate;
+		}
+
 		public String getSchema() {
 			return this.schema;
 		}
@@ -121,4 +135,45 @@ public class BatchProperties {
 
 	}
 
+	/**
+	 * 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();
+		}
+
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -22,6 +22,7 @@ import javax.sql.DataSource;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.boot.autoconfigure.batch.BatchProperties.Isolation;
 import org.springframework.boot.autoconfigure.transaction.TransactionManagerCustomizers;
 import org.springframework.orm.jpa.JpaTransactionManager;
 import org.springframework.transaction.PlatformTransactionManager;
@@ -54,8 +55,15 @@ public class JpaBatchConfigurer extends BasicBatchConfigurer {
 
 	@Override
 	protected String determineIsolationLevel() {
-		logger.warn("JPA does not support custom isolation levels, so locks may not be taken when launching Jobs");
-		return "ISOLATION_DEFAULT";
+		String name = super.determineIsolationLevel();
+		if (name != null) {
+			return name;
+		}
+		else {
+			logger.warn("JPA does not support custom isolation levels, so locks may not be taken when launching Jobs. "
+					+ "To silence this warning, set 'spring.batch.jdbc.isolation-level-for-create' to 'default'.");
+			return Isolation.DEFAULT.toIsolationName();
+		}
 	}
 
 	@Override

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/batch/BatchAutoConfigurationTests.java

@@ -23,6 +23,7 @@ import javax.persistence.EntityManagerFactory;
 import javax.sql.DataSource;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 
 import org.springframework.batch.core.BatchStatus;
 import org.springframework.batch.core.Job;
@@ -57,6 +58,8 @@ import org.springframework.boot.jdbc.init.DataSourceScriptDatabaseInitializer;
 import org.springframework.boot.sql.init.DatabaseInitializationMode;
 import org.springframework.boot.sql.init.DatabaseInitializationSettings;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.test.system.CapturedOutput;
+import org.springframework.boot.test.system.OutputCaptureExtension;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
@@ -78,6 +81,7 @@ import static org.mockito.Mockito.mock;
  * @author Vedran Pavic
  * @author Kazuki Shimizu
  */
+@ExtendWith(OutputCaptureExtension.class)
 class BatchAutoConfigurationTests {
 
 	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
@@ -211,6 +215,30 @@ class BatchAutoConfigurationTests {
 				});
 	}
 
+	@Test
+	void testDefaultIsolationLevelWithJpaLogsWarning(CapturedOutput output) {
+		this.contextRunner.withUserConfiguration(TestConfiguration.class, EmbeddedDataSourceConfiguration.class,
+				HibernateJpaAutoConfiguration.class).run((context) -> {
+					assertThat(context.getBean(BasicBatchConfigurer.class).determineIsolationLevel())
+							.isEqualTo("ISOLATION_DEFAULT");
+					assertThat(output).contains("JPA does not support custom isolation levels")
+							.contains("set 'spring.batch.jdbc.isolation-level-for-create' to 'default'");
+				});
+	}
+
+	@Test
+	void testCustomIsolationLevelWithJpaDoesNotLogWarning(CapturedOutput output) {
+		this.contextRunner.withPropertyValues("spring.batch.jdbc.isolation-level-for-create=default")
+				.withUserConfiguration(TestConfiguration.class, EmbeddedDataSourceConfiguration.class,
+						HibernateJpaAutoConfiguration.class)
+				.run((context) -> {
+					assertThat(context.getBean(BasicBatchConfigurer.class).determineIsolationLevel())
+							.isEqualTo("ISOLATION_DEFAULT");
+					assertThat(output).doesNotContain("JPA does not support custom isolation levels")
+							.doesNotContain("set 'spring.batch.jdbc.isolation-level-for-create' to 'default'");
+				});
+	}
+
 	@Test
 	void testRenamePrefix() {
 		this.contextRunner

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/batch/BatchAutoConfigurationWithoutJpaTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -61,6 +61,7 @@ class BatchAutoConfigurationWithoutJpaTests {
 							.contains("DataSourceTransactionManager");
 					assertThat(context.getBean(BatchProperties.class).getJdbc().getInitializeSchema())
 							.isEqualTo(DatabaseInitializationMode.EMBEDDED);
+					assertThat(context.getBean(BasicBatchConfigurer.class).determineIsolationLevel()).isNull();
 					assertThat(new JdbcTemplate(context.getBean(DataSource.class))
 							.queryForList("select * from BATCH_JOB_EXECUTION")).isEmpty();
 					assertThat(context.getBean(JobExplorer.class).findRunningJobExecutions("test")).isEmpty();
@@ -84,6 +85,15 @@ class BatchAutoConfigurationWithoutJpaTests {
 				});
 	}
 
+	@Test
+	void jdbcWithCustomIsolationLevel() {
+		this.contextRunner.withUserConfiguration(DefaultConfiguration.class, EmbeddedDataSourceConfiguration.class)
+				.withPropertyValues("spring.datasource.generate-unique-name=true",
+						"spring.batch.jdbc.isolation-level-for-create=read_committed")
+				.run((context) -> assertThat(context.getBean(BasicBatchConfigurer.class).determineIsolationLevel())
+						.isEqualTo("ISOLATION_READ_COMMITTED"));
+	}
+
 	@EnableBatchProcessing
 	@TestAutoConfigurationPackage(City.class)
 	static class DefaultConfiguration {