Enable transaction management for JdbcOperationsSessionRepository operations

docs/src/docs/asciidoc/guides/httpsession-jdbc-xml.adoc

@@ -85,6 +85,7 @@ The filter is what is in charge of replacing the `HttpSession` implementation to
 In this instance Spring Session is backed by a relational database.
 <2> We create a `dataSource` that connects Spring Session to an embedded instance of H2 database.
 We configure the H2 database to create database tables using the SQL script which is included in Spring Session.
+<3> We create a `transactionManager` that manages transactions for previously configured `dataSource`.
 
 == XML Servlet Container Initialization
 

docs/src/docs/asciidoc/guides/httpsession-jdbc.adoc

@@ -83,6 +83,7 @@ The filter is what is in charge of replacing the `HttpSession` implementation to
 In this instance Spring Session is backed by a relational database.
 <2> We create a `dataSource` that connects Spring Session to an embedded instance of H2 database.
 We configure the H2 database to create database tables using the SQL script which is included in Spring Session.
+<3> We create a `transactionManager` that manages transactions for previously configured `dataSource`.
 
 == Java Servlet Container Initialization
 

docs/src/docs/asciidoc/index.adoc

@@ -1012,7 +1012,7 @@ A typical example of how to create a new instance can be seen below:
 include::{indexdoc-tests}[tags=new-jdbcoperationssessionrepository]
 ----
 
-For additional information on how to create and configure a `JdbcTemplate`, refer to the Spring Framework Reference Documentation.
+For additional information on how to create and configure `JdbcTemplate` and `PlatformTransactionManager`, refer to the Spring Framework Reference Documentation.
 
 [[api-jdbcoperationssessionrepository-config]]
 ==== EnableJdbcHttpSession
@@ -1056,6 +1056,11 @@ And with MySQL database:
 include::{session-main-resources-dir}org/springframework/session/jdbc/schema-mysql.sql[]
 ----
 
+==== Transaction management
+
+All JDBC operations in `JdbcOperationsSessionRepository` are executed in a transactional manner.
+Transactions are executed with propagation set to `REQUIRES_NEW` in order to avoid unexpected behavior due to interference with existing transactions (for example, executing `save` operation in a thread that already participates in a read-only transaction).
+
 [[community]]
 == Spring Session Community
 

docs/src/test/java/docs/IndexDocTests.java

@@ -20,6 +20,7 @@ import org.junit.Test;
 
 import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
 import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.datasource.DataSourceTransactionManager;
 import org.springframework.mock.web.MockServletContext;
 import org.springframework.session.ExpiringSession;
 import org.springframework.session.MapSessionRepository;
@@ -28,6 +29,7 @@ import org.springframework.session.SessionRepository;
 import org.springframework.session.data.redis.RedisOperationsSessionRepository;
 import org.springframework.session.jdbc.JdbcOperationsSessionRepository;
 import org.springframework.session.web.http.SessionRepositoryFilter;
+import org.springframework.transaction.PlatformTransactionManager;
 import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -124,8 +126,12 @@ public class IndexDocTests {
 
 		// ... configure JdbcTemplate ...
 
+		PlatformTransactionManager transactionManager = new DataSourceTransactionManager();
+
+		// ... configure transactionManager ...
+
 		SessionRepository<? extends ExpiringSession> repository =
-				new JdbcOperationsSessionRepository(jdbcTemplate);
+				new JdbcOperationsSessionRepository(jdbcTemplate, transactionManager);
 		// end::new-jdbcoperationssessionrepository[]
 	}