A Simple Client Application:

Step

Description

Source Code

0

do any necessary imports for application

import EDU.cmu.softagents.misc.KQMLParser.InternalKQMLmessage;

import EDU.cmu.softagents.misc.KQMLParser.ExternalKQMLmessage;

import EDU.cmu.softagents.retsina.Communicator.*

1

Start class and main program

do any necessary initialization and processing

public class Client {

  static Communicator comm = null;

  public static void main ( String argv[] ) throws CommunicatorException, IOException

  {

2

create a new instance of the Communicator.

give it the Client's AgentName, its HostName, and the preferred port number for communication.

    comm = new Communicator( "TestClient",

                             "angel.cimds.ri",

                             0,

                             new InternalKQMLmessage(),

                             new ExternalKQMLmessage(),

                             null,

                             false);

3

Using the comm object, open a connection to a server agent by referencing its Agent's name.  In return you'll get a ConnectionDescriptor that will be used to refer to this client-to-server link.

    ConnectionDescriptor cd = comm.openConnection("TestServer");

4

Create an internal message.

    InternalKQMLmessage reqMsg = new InternalKQMLmessage();

5

Populate the message structure with relevant information; including the "CONTENT".

    reqMsg.setPerformative("ask-one");

    reqMsg.setField(reqMsg.SENDER, "TestClient");

    reqMsg.setField(reqMsg.RECEIVER, "TestServer");

    reqMsg.setField(reqMsg.REPLY_WITH, "");

    reqMsg.setField(reqMsg.IN_REPLY_TO, "");

    reqMsg.setField(reqMsg.CONTENT, "HelloWorld!");

6

Send the message.

After sending the message, wait for a reply message.

Create a new message object called replyMsg and fill it with the information that returns from the server.

    boolean sentOK = comm.sendMsg(cd, reqMsg);

    InternalKQMLmessage replyMsg = (InternalKQMLmessage) comm.waitOnGetInputMsg(cd);

or

   InternalKQMLmessage replyMsg=(InternalKQMLmessage) comm.sendMsgAndGetReply(cd, reqMsg);

7

Extract the CONTENT information from the reply message.

    String result = replyMsg.getField(replyMsg.CONTENT).trim();

8

Do whatever processing is appropriate to the data received.

    System.out.println("**** reply message = " + result + " ****";

9

Close down services and connections and end.

    comm.refuseNewConnection();

    comm.flushMsgsAndStop();

    comm.unRegisterWithANS();

    comm.closeConnection( cd );

    system.exit(0);

  }

Step

Description

Source Code

0

Do any necessary imports for application

import EDU.cmu.softagents.misc.KQMLParser.InternalKQMLmessage;

import EDU.cmu.softagents.misc.KQMLParser.ExternalKQMLmessage;

import EDU.cmu.softagents.retsina.Communicator.*

1

Start class and main program

do any necessary initialization and processing

public class Server {

  static Communicator comm = null;

  public static void main ( String argv[] ) throws CommunicatorException, IOException

  {

2

Create a new instance of the Communicator.

Give it the Client’s AgentName, its HostName, and the preferred port number for communication.

    comm = new Communicator( "TestServer",

                             "angel.cimds.ri",

                             0,

                             new InternalKQMLmessage(),

                             new ExternalKQMLmessage(),

                             null,

                             false);

3

We don't have a connection with another Agent yet, so, wait for a message and then discover the connection details from the incoming message object.

    InputMsgObject iMsgObj = comm.waitOnGetInputMsg();

4

Discover Connection Descriptor and details from incoming Message.

    ConnectionDescriptor cd = comm.lookupConnection(iMsgObj);

5

Extract the message from the message object;

then do whatever processing is required.

    InternalKQMLmessage msg = (InternalKQMLmessage) iMsgObj.getMsg();

    System.out.println("*** message= "+ msg.getField(msg.Content)+" ***");

6

Build a reply message based on the incoming message.

    InternalKQMLmessage replyMsg =

         (InternalKQMLmessage) msg.buildReplyMsg("Reply", "ThisIsTheReply", "nothing");

7

Send the reply message back to the client

    boolean sentOK = comm.sendMsg( cd, replyMsg );

8

Do whatever follow-up processing may be required

//…

9

Close down all services and connections and end.

    comm.refuseNewConnection();

    comm.flushMsgsAndStop();

    comm.unRegisterWithANS();

    system.exit(0);

  }