To do so when using ehcache within a webapp, simply add its ShutdownListener as a listener in web.xml.

<listener>
    <listener-class>net.sf.ehcache.constructs.web.ShutdownListener</listener-class>
</listener>

Alternatively, or when not using ehcache inside a webapp, instruct ehcache to register its own shutdown hook by setting a system property.

net.sf.ehcache.enableShutdownHook=true

If you forget one of the above, your persisted cache may not be up-to-date, or worse, not persisted at all.