This guide describes how to use Spring Session to transparently leverage Redis to back a web application’s
HttpSession when using Spring Boot.
|The completed guide can be found in the boot sample application.|
Before you use Spring Session, you must ensure to update your dependencies. We assume you are working with a working Spring Boot web application. If you are using Maven, ensure to add the following dependencies:
<dependencies> <!-- ... --> <dependency> <groupId>org.springframework.session</groupId> <artifactId>spring-session-data-redis</artifactId> </dependency> </dependencies>
Spring Boot provides dependency management for Spring Session modules, so there’s no need to explicitly declare dependency version.
After adding the required dependencies, we can create our Spring Boot configuration.
Thanks to first-class auto configuration support, setting up Spring Session backed by Redis is as simple as adding a single configuration property to your
spring.session.store-type=redis # Session store type.
Under the hood, Spring Boot will apply configuration that is equivalent to manually adding
This creates a Spring Bean with the name of
springSessionRepositoryFilter that implements Filter.
The filter is what is in charge of replacing the
HttpSession implementation to be backed by Spring Session.
Further customization is possible using
server.servlet.session.timeout= # Session timeout. If a duration suffix is not specified, seconds will be used. spring.session.redis.flush-mode=on-save # Sessions flush mode. spring.session.redis.namespace=spring:session # Namespace for keys used to store sessions.
For more information, refer to Spring Session portion of the Spring Boot documentation.
Spring Boot automatically creates a
RedisConnectionFactory that connects Spring Session to a Redis Server on localhost on port 6379 (default port).
In a production environment you need to ensure to update your configuration to point to your Redis server.
For example, you can include the following in your application.properties
spring.redis.host=localhost # Redis server host. spring.redis.password= # Login password of the redis server. spring.redis.port=6379 # Redis server port.
For more information, refer to Connecting to Redis portion of the Spring Boot documentation.
Our Spring Boot Configuration created a Spring Bean named
springSessionRepositoryFilter that implements
springSessionRepositoryFilter bean is responsible for replacing the
HttpSession with a custom implementation that is backed by Spring Session.
In order for our
Filter to do its magic, Spring needs to load our
Last we need to ensure that our Servlet Container (i.e. Tomcat) uses our
springSessionRepositoryFilter for every request.
Fortunately, Spring Boot takes care of both of these steps for us.
The Boot Sample Application demonstrates how to use Spring Session to transparently leverage Redis to back a web application’s
HttpSession when using Spring Boot.
You can run the sample by obtaining the source code and invoking the following command:
For the sample to work, you must install Redis 2.8+ on localhost and run it with the default port (6379).
Alternatively, you can update the
$ ./gradlew :spring-session-sample-boot-redis:bootRun
You should now be able to access the application at http://localhost:8080/
Try using the application. Enter the following to log in:
Now click the Login button.
You should now see a message indicating your are logged in with the user entered previously.
The user’s information is stored in Redis rather than Tomcat’s
Instead of using Tomcat’s
HttpSession, we are actually persisting the values in Redis.
Spring Session replaces the
HttpSession with an implementation that is backed by Redis.
When Spring Security’s
SecurityContextPersistenceFilter saves the
SecurityContext to the
HttpSession it is then persisted into Redis.
When a new
HttpSession is created, Spring Session creates a cookie named SESSION in your browser that contains the id of your session.
Go ahead and view the cookies (click for help with Chrome or Firefox).
If you like, you can easily remove the session using redis-cli. For example, on a Linux based system you can type:
$ redis-cli keys '*' | xargs redis-cli del
|The Redis documentation has instructions for installing redis-cli.|
Alternatively, you can also delete the explicit key. Enter the following into your terminal ensuring to replace
7e8383a4-082c-4ffe-a4bc-c40fd3363c5e with the value of your SESSION cookie:
$ redis-cli del spring:session:sessions:7e8383a4-082c-4ffe-a4bc-c40fd3363c5e
Now visit the application at http://localhost:8080/ and observe that we are no longer authenticated.