INF 123: Software Architectures, Distributed Systems, and Interoperability

1
INF 123 Software Architectures, Distributed
Systems, and Interoperability

• Discussion Session
• Week 8 - Spring 2008
• Instructor Prof. Richard N. Taylor
• TA Rosalva Gallardo

2
Overview

• Comments about Assignment 2
• Assignment 3
• Lunar Lander Game Server (RMI)

3
Assignment 3

• Assignment 3 and the Discussions Slides for Week
  7 and 8 are in eee.
• Assignment 3 Discussion

4
Deployment
Server Machine
Client Machine
rmiregistry
Lunar Lander Code
Network
edu.uci.inf123 - ServerRMI.java -
SpacecraftStateIntf.java - SpacecraftState.java
edu.uci.inf123 - SpacecraftStateIntf.java -
SpacecraftState.java
5
Implementation Interface

• package edu.uci.inf123
• import java.rmi.Remote
• import java.rmi.RemoteException
• import java.util.HashMap
• public interface SpacecraftStateIntf extends
  Remote
• SpacecraftState getState(String identifier)
  throws RemoteException
• void setState(String identifier,
  SpacecraftState state) throws RemoteException
• void clearState(String identifier) throws
  RemoteException
• HashMapltString, SpacecraftStategt getStates()
  throws RemoteException

6
Implementation Spacecraft Status Bean

• package edu.uci.inf123
• public class SpacecraftState implements
  java.io.Serializable
• private static final long serialVersionUID 1L
• double altitude
• double velocity
• double fuel
• public SpacecraftState()
• altitude 0.0
• velocity 0.0
• fuel 0.0
• public void setAltitude(double pAltitude)
• altitude pAltitude

7
Implementation Server

• package edu.uci.inf123
• import java.rmi.registry.Registry
• import java.rmi.registry.LocateRegistry
• import java.rmi.RemoteException
• import java.rmi.server.UnicastRemoteObject
• import java.util.HashMap
• public class ServerRMI implements
  SpacecraftStateIntf
• HashMapltString, SpacecraftStategt states
• public ServerRMI()
• states new HashMapltString,
  SpacecraftStategt()
• public SpacecraftState getState(String
  identifier) throws RemoteException
• return (SpacecraftState)states.get(identif
  ier)

8
Implementation Server (cont.)

• public static void main(String args)
• try
• ServerRMI obj new ServerRMI()
• SpacecraftStateIntf stub (SpacecraftStateIntf)
  UnicastRemoteObject.exportObject(obj, 0)
• // Bind the remote object's stub in the registry
• System.setProperty("java.rmi.server.hostname",
  "tps.ics.uci.edu")
• Registry registry LocateRegistry.getRegistry()
• registry.bind("SpacecraftStates", stub)
• System.err.println("Server ready")
• catch (Exception e)
• System.err.println("Server exception "
  e.toString())
• e.printStackTrace()

9
Implementation RMI Client

• package edu.uci.inf123
• import java.rmi.registry.LocateRegistry
• import java.rmi.registry.Registry
• import java.util.HashMap
• import java.util.Iterator
• public class ClientRMI
• private ClientRMI()
• public static void main(String args)
• String host "tps.ics.uci.edu"
• try
• Registry registry LocateRegistry.getRegistry
  (host)
• SpacecraftStateIntf stub (SpacecraftStateInt
  f) registry.lookup("SpacecraftStates")
• SpacecraftState ss1, ss2

10
Implementation RMI Client

• ss1.setVelocity(100.00)
• System.out.println("\nState set for
  rgallard_MyLL")
• stub.setState("rgallard_MyLL", ss1)
• System.out.println("\nCurrent States")
• printStates(stub.getStates())
• System.out.println("\nState get for
  rgallard_MyLL")
• ss2 stub.getState("rgallard_MyLL")
• System.out.println("\nCurrent States")
• printStates(stub.getStates())
• System.out.println("\nState cleared for
  rgallard_MyLL")
• stub.clearState("rgallard_MyLL")
• System.out.println("\nCurrent States")

11
Output of RMI Client
12
Important Considerations

• For the name of the Local Spacecraft and Remote
  Spacecraft you should use the following pattern
• uciNetID_NameYouLike
• Ex rgallard_Ariadne
• Make sure you will clean the state of your Local
  Spacecraft when your game finishes. If it is
  necessary run the ClientRMI to clean the states
  you create during your tests

13
Important Considerations

• Make sure you press Return after you enter the
  value in the text fields in the Lunar Lander
  Launcher menu. If you only use your mouse the
  value of the text fields will be null. Be
  careful. You are welcome to change the
  implementation to improve this, but this is not
  required.

14
Important Considerations

• Testing options
• Using one machine
• Test your application with the name for the Local
  Spacecraft and Remote Spacecraft being the same.
• Test your application using two different
  installations of Eclipse.
• Test your application using two different
  machines. You can ask for help to your classmates.

15
Important Considerations

• If you choose to test using two different
  installations of Eclipse. Make sure that you have
  the following in your new Eclipse installation
• SubEclipse Plug-in
• ArchStudio Plug-in
• Check out source code of Myx.fw
• Check out your source code of LL from your SVN
  repository. If you see error makes sure the
  installation of the OpenGL libraries is correct.