1. CS 584 Lecture 18
Assignment
Glenda assignment extended to the Java RMI Deadline
No Java RMI Assignment
Test
Friday, Saturday, Monday

2. Java RMI

3. RMI Programming Steps Coding the source files
Compilation and Deployment
Running

4. Coding the Source Files
There are at least 3 source files
Interface definition
Server Implementation
Client Implementation
HTML file if applet

5. Interface Definition Interface must be public Extends java.rmi.Remote
Must declare java.rmi.RemoteException in throws clause

6. Interface Definition Example
package examples.hello
public interface Hello extends java.rmi.Remote {
String sayHello() throws java.rmi.RemoteException; }

7. Server Implementation
Specifies the remote interface
Defines the constructor
Implements methods
Creates and Installs a security manager
Creates instances of the remote object
Registers the remote object with the RMI remote object registry

8. Server Implementation
package examples.hello
import java.rmi.*;
import java.rmi.server.UnicastRemoteObject
public class HelloImpl
extends UnicastRemoteObject implements Hello {
private String name;

9. Server Implementation
public HelloImpl(String s) throws RemoteException {
super();
name = s; }
public String sayHello() throws RemoteException
return "Hello World";

10. Server Implementation
public static void main(String[] args) {
System.setSecurityManager(new RMISecurityManager());
try {
HelloImpl obj = new HelloImpl("HelloServer");
Naming.rebind("//myhost/HelloServer", obj);
System.out.println("Hello Server bound");
catch(Exception e) {
System.out.println("Err: " + e.getMessage);
e.printStackTrace(); }

11. Client Implementation
Obtain a reference to the "HelloServer" from the server's registry
Invoke the method on the remote object
Use the returned results

12. Client Implementation
package examples.hello
import java.awt.*;
import java.rmi.*;
public class HelloApplet extends java.applet.Applet {
String message = " ";

13. Client Implementation
public void init() {
try {
Hello obj = (Hello)Naming.lookup("//" +
getCodeBase().getHost() + "/HelloServer");
message = obj.sayHello(); }
catch (Exception e) {
System.out.println("Err: " + e.getMessage);
e.printStackTrace();

14. Client Implementation
public void paint(Graphics g) {
g.drawString(message, 25,50); }

15. Compilation Compile the source files using javac
Generate Stub and Skeleton files
client side and server side proxies
generated using rmic on class files

16. Deployment RMI is based on packages
RMI objects need to be in a visible place

17. Execution Start the registry on the server start rmiregistry
Start the server using the java interpreter
Run the applet

18. For More Information See Sun's website for a tutorial
web3.javasoft.com:80/products/jdk/1.1/docs/guide/rmi/getstart.doc.html
Remember the test!!!!!