Tic-Tac-Toe Server

Cary Keesler, Tyler Cady, and Ernesto Sola-Thomas

Milestone 1

Git Practice: Repo

During this milestone we created outlines of the classes that we are going to be using in later milestones. The classes Event, User, ServerHandler, SocketServer, GamingResponse, Request, and Response were created in three different packages: model, server, and socket. Along with all of these classes we needed to create tests to make sure that the classes' functionality works as intended. We also added comments for the classes and their respective methods so that we could create Javadoc documentation for the project.

Question 1:

In your test class SocketServerTest, what happens if you provide a negative value for a port number? (Remember port numbers are always positive) How do you think you can fix these issues?

Answer 1:

It will throw an IllegalArgumentException at runtime. To fix the issue add input validation to verify the value is between (1-65535) valid port number range.

Question 2:

In your ServerHandler class, what happens if you do not override the run() function? Is there an error? Why?

Answer 2:

There would be an error if run wasn't overridden. Since ServerHandler extends Thread and Thread has a method run, if you were to call run on a ServerHandler instance, without overriding, it would use the implementation provided by Thread and would not produce the expected outcome.z

Milestone 2

TicTacToe Server: Repo

In this milestone, we implemented networking between two clients and a server. One client send a move to the server while the other one sends requests for move updates. This allows each client to send moves when they are made and for the other client to receive them within a reasonable period of time. We had to make the server multithreaded so that it could handle requests from multiple clients simultaneously.

Question 1:

Do you have a working System that allows two players to play TicTacToe once? If Yes, support your answer with screenshots of the gameplay at the beginning, mid-game, and game over. If No, explain your progress and challenges.

Answer 1:

Beginning

Mid

End

Question 2:

Explain how the game uses the attribute turn and player of the TicTacToe class to manage the game state between the two distributed game boards. Can we still achieve the same thing without introducing player attributes in this milestone? Why?

Answer 2:

The TicTacToe class uses the turn attribute to keep track of which player's turn it is while playing the game. The play method updates game state by marking current player's symbol (1 or 2) and toggles turn. If the play method were removed it would become very difficult to keep track of the game's state and as such, yeah, without it there is no way to know if the buttons should be enabled or disabled to allow or keep a player from making a move

Question 3:

The server currently deletes or resets the game move once it sends a GamingResponse to the client. Is this necessary? What are the pros and cons?

Answer 3:

By deleting and resetting the game move once it sends a GamingResponse to the client the game gets a few benefits: firstly, by deleting the move in the response you ensure that the response is the most accurate and up-to-date state; second, there is a security benefit by deleting data it prevents clients from manipulating game state on their end. Cons include a lack of game history as players can't see previous moves or games. Because TicTacToe is a solved game this isn't major. However, if this were a game like go or chess it may be beneficial to see game history to improve play. Second, another con is that you can't easily add features like undo.

Question 4:

The ButtonHandler inner class in MainActivity currently loops through all 9 buttons to know which button is clicked. Can you think of a way to not loop through all the buttons? You can implement it to support your explanation, but it is not compulsory.

Answer 4:

Yes. It is possible to not loop through all the buttons. This could be achieved using a modified ButtonHandler that uses setTag and getTag methods from android's view class. In this case setTag could be used to give every button a unique tag in the format row:col where row and col are the positions of the button. getTag could then be used to retrieve the tag that matches the button in the onClick method.

Milestone 2

In this milestone we implemented the connection to the database that we are going to be using. We changed our existing code in a variety of locations to make it interface with the database and also wrote tests to make sure that the connection to the database and the sending of events is working as intended.

Question 1:

Show output for each test case after running PairingTest. If you are not getting an expected output, explain your challenges in each test case.

Answer 1:

Question 2:

What is the difference between COMPLETE_GAME and ABORT_GAME requests?

Answer 2:

COMPLETE_GAME indicates that the game was completed properly. ABORT_GAME indicates that the game was improperly completed or that a game invitation was rejected.

Question 3:

With the current implementation, can two users login to the system using the same account credentials? Why or Why not?

Answer 3:

Currently, two users with the same credentials can log in to the system. This is because the players online status is not checked in handleLogin before logging the user in.

Question 4:

Explain the stages of EventStatus and object Event class goes through in the game process. Use the “The Flow of Game Event” diagram above as a guide.

Answer 4:

Player one sends an invitation to player 2. Player two can either accept it or decline it. In the case of a declined invitation, the game is aborted. If the invitation is accepted, then you proceed to the playing state. From there you can go to one of two states, a completed game or and aborted one. If the game is aborted then the players move on to a new game. If the game is completed then they do the same but the game will be complete.

Question 5:

In Part 2 - Task 3, the code snippet given to you clears the database before starting the server. Is it necessary? What happens to your test if that line is removed?

Answer 5:

That line is necessary. If that line is removed, the register tests would no longer function as intended because the user would already exist.