12.6.1.7 TCP Communication

Default Implementation for TCP

In Distributed Mediation Server, the TCPProbeCommInit implementation takes care of establishing the connection with the Central Server. This class implements the SPPCommInitIfc and the open() method is used to establish the connection by opening a new socket as shown below:

...

String serverName = NOCServerCommAPI.getInstance().getNOCServerName();

int port = NOCServerCommAPI.getInstance().getNOCServerPort();

Socket socket = new Socket(serverName, port);

...

At the Central Server, the TCPServerCommInit implementation takes care of establishing the connection with the Distributed Mediation Server. This class implements the SPPCommInitIfc and the init() parameter creates the server socket for initializing the communication, as shown below:

...

int port = Integer.parseInt(SPPCommParser.getInstance().getUserProperty("ListenPort"));

...

ssocket = new ServerSocket(port);

...

The open() method waits and accepts the connection from the Distributed Mediation Server, as shown below:

...

Socket socket = null;

try

{

socket = ssocket.accept();

}

catch(Exception ex)

{

throw new CommunicationException(ex.toString());

}

return new TCPSessionCommImpl(socket);

...

The shutdown() method releases the server socket when the server is shutdown.

The TCPSessionCommImpl implementation takes care of the actual operations once the connection is established. This class implements the SPPRegionalCommIfc and contains the logic for read and write operations. The initialize() method gets the instance of the read and write streams and returns true if the instance has been successfully obtained. The read() method reads the data by reading from the socket and the write() method writes the data to the socket, as shown below:

...

Object object = readStream.readObject();

dataObject = (DataObject)object;

...

writeStream.writeObject(dataObject);

...

Sample Entries in CommunicationInfo.xml

In Central Server

...

</UserProps>

</Communication>

...

In Distributed Mediation Server

...

</UserProps>

</Communication>

...