Add MongoDB support to Spring Session sample

Closes gh-10374

spring-boot-samples/spring-boot-sample-session/README.adoc

@@ -6,6 +6,7 @@ supports multiple session store types, including:
 * `Redis`
 * `JDBC`
 * `Hazelcast`
+* `MongoDB`
 
 
 
@@ -46,3 +47,14 @@ automatically configure the underlying `HazelcastInstance`.
 
 TIP: Run sample application using Hazelcast session store with
 `$mvn spring-boot:run -Phazelcast`.
+
+
+
+=== MongoDB
+Add `org.springframework.session:spring-session-data-mongodb` and
+`spring-boot-starter-data-mongodb` dependencies to the project and make sure it is
+configured properly (by default, a MongoDB instance with the default settings is expected
+on your local box).
+
+TIP: Run sample application using MongoDB session store using
+`$mvn spring-boot:run -Pmongodb`.

spring-boot-samples/spring-boot-sample-session/pom.xml

@@ -94,5 +94,18 @@
 				</dependency>
 			</dependencies>
 		</profile>
+		<profile>
+			<id>mongodb</id>
+			<dependencies>
+				<dependency>
+					<groupId>org.springframework.session</groupId>
+					<artifactId>spring-session-data-mongodb</artifactId>
+				</dependency>
+				<dependency>
+					<groupId>org.springframework.boot</groupId>
+					<artifactId>spring-boot-starter-data-mongodb</artifactId>
+				</dependency>
+			</dependencies>
+		</profile>
 	</profiles>
 </project>