I am developing a Java application and realized that I need
some advice. My application is simple:
* a PostgreSQL server with GIS data I want to display on
* Tomcat 5.5
* Flex Data Services
Basically, I need to query and create 10000+ GIS data objects
from the DB and store them in the server memory. A Flex client then
uses Remote Object Service to access the properties of all the
objects. A user will choose which objects to be displayed and this
info is send back to the server. The server then compiles a KML
file according to the user's pick. As KML allows user to send
updates by only sending the diff KML, this makes it easy to turn
the visibility of a small number of objects on and off.
My problem is, I do not know a way to keep a session in the
server memory. I need to find a way to store all the objects in the
server memory so that I can keep track of the state (displayed or
not displayed) of each object. All the tutorials I Googled only
give examples of how you can update changes to the DB. But that's
not what I want. I only want to make one giant DB query at the
beginning of the session and stores the result in memory. This way,
I can change the state of each object on the fly.
You could change the <scope> property of your
to be the session scope so that the same instance of the
would be used for the entire session. That way you could
store the result
as a member variable.
Alternatively, you could get access to the session from the
method and store the data in an attribute on the session?