Interfaces and Polymorphism - Java Concepts - page 598

Design an interface Game that describes a board game. Think about what
your program needs to do. It asks the first player to input a moveȌa
string in a game-specific format, such as Be3 in chess. Your program
knows nothing about specific games, so the Game interface must have a
method such as

boolean isValidMove(String move)

Once the move is found to be valid, it needs to be executedȌthe
interface needs another method executeMove . Next, your program
needs to check whether the game is over. If not, the other player's move
is processed. You should also provide some mechanism for displaying
the current state of the board.

Design the Game interface and provide two implementations of your
choiceȌsuch as Nim and Chess (or TicTacToe if you are less
ambitious). Your GamePlayer class should manage a Game reference
without knowing which game is played, and process the moves from
both players. Supply two programs that differ only in the initialization of
the Game reference.

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ANSWERS TO SELF-CHECK QUESTIONS

1. It must implement the Measurable interface, and its getMeasure
method must return the population.

2. The Object class doesn't have a getMeasure method, and the add
method invokes the getMeasure method.

3. Only if x actually refers to a BankAccount object.

4. NoȌa Coin reference can be converted to a Measurable reference, but
if you attempt to cast that reference to a BankAccount , an exception
occurs.

5. Measurable is an interface. Interfaces have no fields and no method
implementations.