JMX allow remote controle on components, in Spring it is easy to declare which component have to be exposed in JMX.
The following sample shows how to control a CaptchaService and a ContainerManager:
Thanks to a JMX interface, like the one provide in JBoss or MC4J, you can manage the captcha buffering system and your Captcha Service very easily. Every operation available is define in ContainerManager and Captcha Service interfaces. See the java doc for BufferedEngineContainerManager and AbstractManageableCaptchaService.