Getting java.io.NotSerializableException with a spring service when stopping tomcat

Question

i am using spring 3 with JSF 2 and i replaced JSF managed beans with spring beans, by adding on top of bean:

@Component(\"mybean\")
@Scope(\"session\")
         


        

Answer 1

You get this exception because the class does not implement Serializable. Tomcat serializes currently running HttpSession objects including all its attributes to disk whenever it is about to restart/redeploy, so that they are revived after the cycle. Session scoped objects are stored as attributes of the HttpSession, hence they need to implement Serializable to survive the restart/redeploy as well.

If you would like to make them Serializable, then implement it accordingly:

public class YourSpringService implements Serializable {}

Otherwise, just ignore the exception or turn off serializing sessions to disk in Tomcat's config.

Note that the same story also applies to JSF view/session scoped beans.