The client comunicates with the server by sending java code to be executed.
The clients request is composed by the operations to be executed and complex objects that the server returns to the client.
Only certain datatypes are allowed to be transferred between client and server (String, Integer, DateTime , etc..) If you want to transfer your own class it must implement the serializable interface.
If the client requires parameters for the execution of the code, these are sen to the server with the parameter object (key-value collection), whilst  al return values are specified in the response object (key-value collection).
The client also has the chance to observe , thru the Observer/Observable pattern, what is happening on the server.
The objects that make this possible are:

  • clientObserver
  • executeObserver

The first allows to observe objects for the whole life of the session, whilst the later for the liftime of the request. clientObserver notifies all events of the observed objects, whilst executeObserver notifies available events on a regular time basis, avoiding to much connection overhead. Briefly clientObserver notifies server side events, executeObserver verifies request execution state.
Before the client can start to work it must open a session on the server, this assigns a work-area to the user in which code execution is possible. For every session one o more stream channels can be opened for sending or receiving data (video, audio, etc..).
Dataweb Project uses tcp-ip as comunication protocol on the following ports:

  • TCP 7720 In clear.
  • TCP 7730 Encrypted (SSL).

Last updatedThursday, 18 November 2010 16:34