Java™ Application Development on Linux - Dator

5.8 Introducing RMI143Example 5.12 The RMI client programpackage net.multitool.RMIDemo;import java.rmi.*;public class Client {public static void main(String[] arglist) {if (System.getSecurityManager() == null) {System.setSecurityManager(new RMISecurityManager());}try {String name = "//penfold/Session";// Obtain reference to the remote objectSession sess = (Session) Naming.lookup(name);}}System.out.println("Pointless RMI Client. 47 + 13 = " +sess.add(47,13) + ", right?");} catch (Exception e) {e.printStackTrace();}5.8.2 The rmic ToolIn order for a remote object to make itself available and in order for a client tobe able to call such an object, each method needs a client and server-side stubto proxy the method call. Arguments to the method call are converted tostreamable data (this process is called marshaling) by the client stub, and thatdata is sent over the network to the server stub, which must convert that streaminto object instances on the server side (this is called unmarshaling). The serversidestub then calls the actual method implementation. When the method returns,any return values and changes to the state of the arguments must bemarshaled by the server stub and sent back to the client stub where they areunmarshaled and stored in the correct locations on the client.This was the traditionally painful part of writing multitier clients. Whatrmic does is automate the generation of these stubs, so writing a remote methodis only slightly more difficult than writing any other method.