New York University

Computer Science Department

Courant Institute of Mathematical Sciences

Session 3: RMI-IIOP MOO Framework Installation Instructions

Course Title: XML for Java Developers Course Number: g22.3033-002

Instructor: Jean-Claude Franchitti Session: 3

Installation and Test

1. Extract RMI-IIOP-MOO.zip using winzip under c:\.

2. After extraction, a directory named c:\RMI-IIOP-MOO is created, which includes subdirectory ChatClientRMI and ChatServerRMI.

3. Switch to c:\RMI-IIOP-MOO, and run the file “env.bat” to set the CLASSPATH.

4. Start the naming service “tnameserv” using default settings.

5. Test

> cd c:\RMI-IIOP-MOO

> env.bat

> start tnameserv

> c:\RMI-IIOP-MOO\ChatServerRMI\runs.bat

Open another DOS prompt

> c:\RMI-IIOP-MOO\ChatClientRMI\runc.bat prof

Open another DOS prompt

> c:\RMI-IIOP-MOO\ChatClientRMI\runc.bat student

Design and Implementation

1. The chat room is implemented with RMI-IIOP, and the client side is a Java application.

2. RMI interfaces are similar to the IDL ones

ChatServerRMI.java describes the interfaces to the server.

connect: called by client when the chat user connects to the server.

disconnect: called by client when the chat user disconnects to the

server.

sendMessage: called by server when new user (dis)connect, or by client

when some user send a message to others.

sendLocation: called by client when some user move his/her position in

the graph.

ChatClientRMI.java describes the interfaces to the client.

updateMessage: called by server when new messages arrives

updateLocation: called by server when location changed for some user

3. Communication

Messages are transferred via strings or integers, while more complicated messages are encoded in strings instead of sending objects.

4. Client implementation

Each client has a user list to keep track of all the online users. Each user has a record to record his/her info: like name, location, etc.

The display of chat room is updated at some time interval, timer is used to decide if a message should be displayed.

5. Server implementation

There are five differrent servers (chat rooms), and each has a user list to keep track of all its online users. Furthermore, the client can enter any one of the five chat rooms, even after it has left another room.