73 lines
1.8 KiB
Java
73 lines
1.8 KiB
Java
// functional/Games.java
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// ©2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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// Using anonymous inner classes with the Game framework.
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interface Game { boolean move(); }
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interface GameFactory { Game getGame(); }
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class Checkers implements Game {
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private Checkers() {}
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private int moves = 0;
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private static final int MOVES = 3;
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@Override
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public boolean move() {
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System.out.println("Checkers move " + moves);
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return ++moves != MOVES;
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}
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public static GameFactory factory = new GameFactory() {
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public Game getGame() { return new Checkers(); }
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};
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}
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class Chess implements Game {
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private Chess() {}
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private int moves = 0;
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private static final int MOVES = 4;
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public boolean move() {
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System.out.println("Chess move " + moves);
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return ++moves != MOVES;
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}
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// Use a lambda expression instead:
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public static GameFactory factory = () -> new Chess();
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}
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class TicTacToe implements Game {
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private TicTacToe() {}
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private int moves = 0;
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private static final int MOVES = 4;
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public boolean move() {
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System.out.println("TicTacToe move " + moves);
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return ++moves != MOVES;
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}
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// Use a method reference instead:
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public static GameFactory factory = TicTacToe::new;
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}
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public class Games {
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public static void playGame(GameFactory factory) {
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Game s = factory.getGame();
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while(s.move())
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;
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}
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public static void main(String[] args) {
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playGame(Checkers.factory);
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playGame(Chess.factory);
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playGame(TicTacToe.factory);
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}
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}
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/* Output:
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Checkers move 0
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Checkers move 1
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Checkers move 2
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Chess move 0
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Chess move 1
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Chess move 2
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Chess move 3
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TicTacToe move 0
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TicTacToe move 1
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TicTacToe move 2
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TicTacToe move 3
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*/
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