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Flex Data Services + java server sessions

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Hello, folks,



I am developing a Java application and realized that I need
some advice. My application is simple:



I have

* a PostgreSQL server with GIS data I want to display on
Google Earth

* 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.



So please give me some suggestions on this.



Thanks.
1 Reply

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Former Community Member
Are you using RemoteObject?



You could change the <scope> property of your
remoting-service destination

to be the session scope so that the same instance of the
RemoteObject source

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
flex.messaging.FlexContext.getFlexSession()

method and store the data in an attribute on the session?