Due: Monday, February 10, 4 PM (in class).

Here is a (partial) solution. The code is in the new version of the game package $CS680/games2.

This homework will serve as your introduction to the existing version of the game package. We'll be working on enhancing it and reengineering it for several weeks, learning design and design patterns along the way.

You will find all the code for version 1 of the games package in $CS680/games1.

• Replace the call

      game = (Game)(Class.forName(gameName).newInstance()); 
  

  in PlayGame.java by the call

      game = GameFactory.create(gamename);
  

  That means you will have to design and write the factory class GameFactory in package game. Read about the factory design pattern in Jia, pages 294-295. Don't bother with a GameFactory interface. Just write a static method in class GameFactory. You might want to check out the reference in the footnote on page 295.

  Since some of the classes are in the game package and some are not, you need to get the classpath right. In $CS680/games1 you can run PlayGame this way:

     java -classpath classes:gamepackage/classes PlayGame Easy Speedy
  

  To compile and run your own versions, copy everything from games1 (including the makefile) and work from your own place. Use

      cp -r	     
  

  to copy subdirectories recursively.

• Think about whether there should be a PlayerFactory in the game package. Discuss the reasons for and against.

• Read about the singleton design pattern in Jia - pages 114 and 251.
  • Should the instances of class Game returned by the GameFactory be singletons?
  • What is there about how the game package deals with PlayerNumber that resembles the singleton design pattern? In what ways is it different? (The point of this question is not to get a correct answer. It's to make you read through code that provides a type-safe way to create "symbolic constants" in Java, so that you will know how to do that in your own code.)

• Study the code for the game package and its drivers. Comment on some part of the design you found interesting or instructive.

• Draw a UML sequence diagram for the method call

     114                  m = ((ComputerPlayer)player).findbest(g);
  

  in PlayGame.java when the ComputerPlayer is an instance of class Speedy and the Game is Easy. (II haven't done this myself yet. It may be quite complex. If it gets too long, you may fudge some of the deeper stuff as long as you show clearly that you really understand how a UML sequence diagram works.)

• Find a classmate to work together with to translate one of the games currently written in c to the equivalent in Java. If possible, at least one of the two of you should have taken CS310 here at UMass.

  The games to be translated are in $CS310/games1/c. Choose the one you want to work on. Follow this link to find the current assignments and a discussion of the port to Java from C.

  No due date has yet been set for this part of the assignment.

• hard copy of the answers to the questions asked,
• hard copy of your Java source code, and
• a memo discussing your design and coding process. Where did you encounter problems? How did you solve them? What did you learn?

Leave source code in a hw2 subdirectory of your cs680 course directory. Do not alter any permissions.