| <html> |
| <head> |
| <title>Five-in-a-row v 0.0</title> |
| </head> |
| <body LANG="en-US"> |
| <h1> |
| <i>Five-in-a-row |
| </i> 0.0 supplementary documentation |
| </h1> |
| <h3>Introduction and rules |
| </h3> |
| <p> |
| <i>Five-in-a-row |
| </i> is a two player strategy game. The players |
| are connected via network using CORBA-based RMI/IIOP protocol and |
| make they moves with the help of the Swing-based |
| interface. While playing, the users can also chat. |
| </p> |
| <p>The system consists of the single server and any number of |
| interconnected players. The person, willing to play, starts the |
| client and connects the server. The server redirects call to the |
| partner that has previously connected the same server, also willing |
| to play. |
| </p> |
| <p>The game desk is a field where it is possible to set O's |
| and X'es, one per move. The goal is to get five O's in a row while |
| preventing your partner from getting five X's in a row. Vertical, |
| horizontal and diagonal rows are allowed. The system detects the |
| loss-victory situation on the desk, but currently does not serve as a |
| playing partner, requiring at least two human players for this game. |
| </p> |
| <p>Both players can at any time reset the game (restarting it with |
| the same player) or leave the game (disconnecting). The disconnected |
| player can contact the game manager again, requesting to find another |
| partner. |
| </p> |
| <p>Simple as it is, the application has some features of the typical |
| role playing game that frequently just has more states, actions, |
| possible moves and also provides far richer graphics environment. The |
| game manger serves as a World-Wide-Pub where you can always find a |
| partner to play. |
| |
| The players can made both unsynchronized (chatting, game reset and |
| leaving) and synchronized (moves) actions. The game state changes |
| while playing, and the set of the available actions depends on the |
| current state. Finally, the mouse and canvas are involved. However |
| using RMI/IIOP machinery allowed to implement all this functionality |
| with just 13 classes (plus 4 generated), all of them being rather |
| simple. |
| |
| This example refers to the standard classes only and must be buildable |
| from your IDE as long as it has any java 1.4 compiler. |
| </p> |
| <p> |
| The used IIOP protocol must ensure interoperability, allowing players |
| to use different java virtual machines and operating systems. |
| The processors may have the opposite byte order. |
| </p> |
| <h3>Configuration and run |
| </h3> |
| <p>The game manager server executable class is |
| <i>gnu.classpath.examples.CORBA.swing.x5.X5Server |
| </i>. After start, |
| it will print to console the Internet address that must be entered to |
| the client to reach the manager. |
| </p> |
| <p>The client executable class it |
| <i>gnu.classpath.examples.CORBA.swing.x5.Demo |
| </i>. |
| </p> |
| <p>The game should run with GNU Classpath |
| 0.19 and Sun Microsystems java 1.5.0_04. Due later fixed bugs it will |
| not run with the older versions of these two implementations. |
| </p> |
| <p>The game manager HTTP server uses port |
| 1500. Hence all firewalls between the server and the player must be |
| configured to allow HTTP on 1500. The ports, used by the RMI/IIOP are |
| not persistent. GNU Classpath is configured to take ports 1501, 1502 |
| and 1503 (the firewalls must allow to use them for RMI/IIOP). The |
| CORBA implementation other than Classpath may use different port |
| values. Unfortunately, there is no standard method to configure the |
| used port range in a vendor-independent way. |
| </p> |
| <h3>The game server |
| </h3> |
| <p>The game manager is first reachable via http:// protocol (for |
| instance http://123.456.7.89:1500). The simple server at this port |
| always serves much longer string, representing the CORBA stringified |
| object reference (IOR). The |
| <i>Five-in-a-row |
| </i>client uses |
| this reference to find and access the remote game server object. |
| </p> |
| <p>If the server player queue is empty, it simply queues this player. |
| If the queue is not empty, the server introduces the arrived player |
| and queued player to each other as leaves the them alone. When |
| playing, the two clients communicate with each other directly, so the |
| server is just a “meeting point” where the players can |
| find each other. The game server is a console-only application. |
| </p> |
| <p>The initial server http:// address must be transferred to players |
| by some other means of communication (web chat, E-mail, link in a web |
| site and so on). The server writes this address to the specified |
| file, and the client can also take the default value from the same |
| file. This is convenient when all applications run on a single |
| machine, but also may be used to transfer the address via shared |
| filesystem. |
| </p> |
| <h3>The game client |
| </h3> |
| <p>The clients are Swing-based GUI applications, capable for remote |
| communication with each other and with the game manager. They have a |
| set of predefined states and switch between these states in |
| accordance to the preprogrammed logic. The client states are defined |
| in the |
| <i>State |
| </i> interface. They are displayed in the bottom left |
| corner of the window and are summarized in the following table: |
| </p> |
| <table BORDER=1 CELLPADDING=4 CELLSPACING=0 WIDTH="100%"> |
| <thead> |
| <tr BGCOLOR="#ccccff"> |
| <th BGCOLOR="#e6e6ff"> |
| Our state |
| </th> |
| <th BGCOLOR="#e6e6ff"> |
| Partner state |
| </th> |
| <th BGCOLOR="#e6e6ff"> |
| Possible actions |
| </th> |
| <th BGCOLOR="#e6e6ff"> |
| Comment |
| </th> |
| </tr> |
| </thead> |
| <tbody> |
| <tr> |
| <td> |
| Disconnected |
| </td> |
| <td> |
| Partner not accessible |
| </td> |
| <td> |
| Connect |
| </td> |
| <td> |
| Initial state. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| Queued |
| </td> |
| <td> |
| Partner not accessible |
| </td> |
| <td> |
| Leave |
| </td> |
| <td> |
| Queued by the game manager. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| I think. |
| </td> |
| <td> |
| I wait for your move |
| </td> |
| <td> |
| Make move, reset game, leave, chat. |
| </td> |
| <td> |
| The person who waited for another player to come starts |
| the game first. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| I wait for your move |
| </td> |
| <td> |
| I think |
| </td> |
| <td> |
| Chat, reset game, leave. |
| </td> |
| <td> |
| After the partner makes the move, the state changes to |
| <i>I think |
| </i>, unless the end of game situation is detected by |
| the desk analyzer. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| I have lost |
| </td> |
| <td> |
| I have won |
| </td> |
| <td> |
| Chat, reset game, leave. |
| </td> |
| <td> |
| Can be entered with the help of the desk analyzer only. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| I have won |
| </td> |
| <td> |
| I have lost |
| </td> |
| <td> |
| Chat, reset game, leave |
| </td> |
| <td> |
| Can be entered with the help of the desk analyzer only. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| Error |
| </td> |
| <td> |
| Any |
| </td> |
| <td> |
| Chat, leave |
| </td> |
| <td> |
| This should never happen under normal work, but the demo |
| program may be modified by the user. |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| <br> |
| <br> |
| As it is seen, being in one of the states, the client expects to |
| be the partner client in a certain defined state, and both clients |
| change they states in a synchronized manner. Each state has its own |
| set of the available actions and each action either preserves the |
| current state (chat, reset) or changes it following the rules. For |
| this simple example, the state change rules are obvious. |
| <h3>The used RMI-IIOP architecture |
| </h3> |
| Both player and game manager servants are derived from the |
| <i>org.omg.PortableServer.Servant |
| </i> and, being servants, are simply |
| connected to the |
| <i>POA |
| </i>with |
| <i>POA.servant_to_reference |
| </i>. The |
| first remote object (game manager) is found using the stringified |
| object reference. No naming service is involved. |
| </p> |
| Where required, the CORBA objects are narrowed into required |
| player and game manager interfaces using method |
| <i>PortableRemoteObject.narrow(org.omg.CORBA.Object object, Class |
| interface_class) |
| </i>, passing the actual interface of the object as |
| the second parameter. After narrowing, the remote side obtains |
| possibility to invoke remote methods, defined in the interface of |
| this object. After the first remote object is found, other objects |
| can be simply passed as the method parameters. For instance, the game |
| manager introduces another player by passing its reference as a |
| parameter to the method |
| <i>Player.start_game. |
| </i> |
| <h3>Class and interface summary |
| </h3> |
| <table BORDER=1 CELLPADDING=3 CELLSPACING=0 WIDTH="100%"> |
| <col> |
| <col> |
| <tr> |
| <th COLSPAN=2 BGCOLOR="#e6e6ff"> |
| Executables classes |
| </th> |
| </tr> |
| <tr> |
| <td> |
| Demo |
| </td> |
| <td> |
| The main executable class of the game client. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| X5Server |
| </td> |
| <td> |
| The main executable class of the game manager server. |
| </td> |
| </tr> |
| </table> |
| <p></p> |
| <table BORDER=1 CELLPADDING=3 CELLSPACING=0 WIDTH="100%"> |
| <tr BGCOLOR="#ccccff"> |
| <th COLSPAN=2 BGCOLOR="#e6e6ff"> |
| Interface Summary |
| </th> |
| </tr> |
| <tr> |
| <td> |
| GameManager |
| </td> |
| <td> |
| The game manager interface. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| Player |
| </td> |
| <td> |
| Defines remote methods that are invoked by another player or by |
| the challenge server. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| State |
| </td> |
| <td> |
| Defines the states in that the player can be. |
| </td> |
| </tr> |
| </table> |
| |
| <table BORDER=1 CELLPADDING=3 CELLSPACING=0 WIDTH="100%"> |
| <col> |
| <col> |
| <tr BGCOLOR="#ccccff"> |
| <th COLSPAN=2 BGCOLOR="#e6e6ff"> |
| Class Summary |
| </th> |
| </tr> |
| <tr> |
| <td> |
| _GameManager_Stub |
| </td> |
| <td> |
| Normally generated with rmic compiler, this class represents |
| the GameManager Stub on the client side. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| _GameManagerImpl_Tie |
| </td> |
| <td> |
| Normally generated with rmic compiler, this class represents |
| the GameManager Tie on the client side. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| _Player_Stub |
| </td> |
| <td> |
| Generate with rmic, command line rmic -iiop -poa -keep |
| gnu.classpath.examples.CORBA.swing.x5.PlayerImpl (the compiled |
| package must be present in the current folder). |
| </td> |
| </tr> |
| <tr> |
| <td> |
| _PlayerImpl_Tie |
| </td> |
| <td> |
| Generate with rmic, command line rmic -iiop -poa -keep |
| gnu.classpath.examples.CORBA.swing.x5.PlayerImpl (the compiled |
| package must be present in the current folder). |
| </td> |
| </tr> |
| <tr> |
| <td> |
| ChatConstants |
| </td> |
| <td> |
| The chat color code constants, used to indicate who is talking. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| ClientFrame |
| </td> |
| <td> |
| The JFrame of the GUI client. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| GameManagerImpl |
| </td> |
| <td> |
| The manager connects two players into the game. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| IorReader |
| </td> |
| <td> |
| Reads the remote URL. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| OrbStarter |
| </td> |
| <td> |
| Starts the ORBs, involved into this application. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| PlayerImpl |
| </td> |
| <td> |
| The implementation of the PlayerCommunicator, providing the |
| local functionality. |
| </td> |
| </tr> |
| <tr> |
| <td> |
| PlayingDesk |
| </td> |
| <td> |
| Manages actions, related to the game rules and also does all |
| painting. |
| </td> |
| </tr> |
| </table> |
| <h3>See also |
| </h3> |
| <p> |
| <a HREF="http://www.javascripter.net/games/xo/xo.htm">http://www.javascripter.net/games/xo/xo.htm |
| </a> |
| </p> |
| <p> |
| <a HREF="http://www.leepoint.net/notes-java/45examples/55games/five/five.html">http://www.leepoint.net/notes-java/45examples/55games/five/five.html |
| </a> |
| </p> |
| <p>Copyright |
| </p> |
| <p> |
| <font COLOR="#b3b3b3">Copyright (C) 2005 Free Software Foundation, |
| Inc. This file is part of GNU Classpath. GNU Classpath is free |
| software; you can redistribute it and/or modify it under the terms of |
| the GNU General Public License as published by the Free Software |
| Foundation; either version 2, or (at your option) any later version. |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. You should have received a |
| copy of the GNU General Public License along with GNU Classpath; see |
| the file COPYING. If not, write to the Free Software Foundation, |
| Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. As a special exception, the copyright holders of this |
| library give you permission to link this library with independent |
| modules to produce an executable, regardless of the license terms of |
| these independent modules, and to copy and distribute the resulting |
| executable under terms of your choice, provided that you also meet, |
| for each linked independent module, the terms and conditions of the |
| license of that module. An independent module is a module which is |
| not derived from or based on this library. If you modify this |
| library, you may extend this exception to your version of the |
| library, but you are not obligated to do so. If you do not wish to do |
| so, delete this exception statement from your version. |
| </font> |
| </p> |
| <p> |
| <br> |
| <br> |
| </p> |
| <p> |
| First version written by <a href="http://savannah.gnu.org/users/audriusa"> |
| Audrius Meškauskas</a> |
| </p> |
| </body> |
| </html> |
