When using the container framework and extending the containers with Java actions you can do some pretty interesting things. One common request has been for how to create memory state within your action. Since the action can be re-used across many instances of a component (many Eclipse view parts), if the action wants to save state per instance, it needs to account for that. The tutorial uses the secondary identifier of the view part (where in composite applications is unique) to store the state in a map. The tutorial uses MLB.com as a sample to pull information from the web pages and then store the values in our property map. The custom action then prints the “state” for the properties.
Here is a link to the tutorial.