THE UNIVERSITY OF WESTERN AUSTRALIA

Department of Computer Science

230.304 CONCURRENT PROGRAMMING

Laboratory Sheet on Java Remote Method Invocation (RMI)

The purpose of this lab is to learn how to use Java RMI. Some example files and step-by-step instructions are supplied. If you missed the lecture on RMI, see the RMI lecture note.

Tasks

Hello.java contains the interface.
HelloImplementation.java contains the server code.
RemoteHelloClient.java contains the client code.
test.policy is the file with security policy. This will be needed later.
We will first run both the client and the server on the same machine under the same login i.e., your login.
Compile the two files HelloImplementation.java and RemoteHelloClient.java in the usual way, i.e., by using javac
Use the RMI compiler rmic to compile the HelloImplementation class file :
rmic HelloImplementation
This will create the stub and skeleton files :
HelloImplementation_Skel.class and HelloImplementation_Stub.class
Now start the RMI registry in the background :
rmiregistry&
Now bind the server to the RMI registry :
java -Djava.security.policy=test.policy HelloImplementation
Now execute the client :
java -Djava.security.policy=test.policy RemoteHelloClient
You will get the output from the server.
Remember to set read permission for all your files including test.policy

To run this from another machine :

Let your current machine be the host and a friend's machine (where your friend is logged in) be the client.
ftp the files HelloImplementation_Stub.class and test.policy in a directory in your friend's machine.
ftp also the file RemoteHelloClient.java in the same directory. Compile this file through javac and run it :
java -Djava.security.policy=test.policy RemoteHelloClient
Try with different messages in HelloImplementation.java. Remember, every time you change this file in the server, you have to compile it and you have to run rmic to generate the stub and skeleton.

Amitava Datta
May, 2000