じゃんけん

RockPaperScissors

import java.util.EnumMap;
import java.util.Map;
import java.util.Random;
import java.util.function.Supplier;
 
public class RockPaperScissors {
    class FormatException extends Exception {
 
        public FormatException(String message) {
            super(message);
        }
        
        public FormatException(Throwable cause) {
            super(cause);
        }
    }
 
    enum Result {
        WIN {
            @Override
            public String toString() {
                return "I Win!";
            }
        },
        LOSE {
            @Override
            public String toString() {
                return "I Lose!";
            }
        },
        DRAW {
            @Override
            public String toString() {
                return "Draw\nOnce Again!";
            }
        }
    }
 
    enum Hand {
        ROCK, PAPER, SCISSORS
    }
 
    class Judge {
        private final Map<Hand, Result> judgeMap;
        
        public Judge(Supplier<Map<Hand, Result>> supplier) {
            judgeMap = supplier.get();
        }
        
        public Result judge(Hand other) {
            return judgeMap.get(other);
        }
    }
    
    private final static int HAND_SIZE = 3;
    private final Random random = new Random();
    private final Map<Hand, Judge> judges;
 
    private int winCount;
    private int loseCount;
    
    {
        judges = new EnumMap<>(Hand.class);
        judges.put(Hand.ROCK, new Judge(() -> {
            Map<Hand, Result> map = new EnumMap<>(Hand.class);
            map.put(Hand.PAPER, Result.LOSE);
            map.put(Hand.SCISSORS, Result.WIN);
            map.put(Hand.ROCK, Result.DRAW);
            return map;
        }));
        judges.put(Hand.PAPER, new Judge(() -> {
            Map<Hand, Result> map = new EnumMap<>(Hand.class);
            map.put(Hand.SCISSORS, Result.LOSE);
            map.put(Hand.ROCK, Result.WIN);
            map.put(Hand.PAPER, Result.DRAW);
            return map;
        }));
        judges.put(Hand.SCISSORS, new Judge(() -> {
            Map<Hand, Result> map = new EnumMap<>(Hand.class);
            map.put(Hand.ROCK, Result.LOSE);
            map.put(Hand.PAPER, Result.WIN);
            map.put(Hand.SCISSORS, Result.DRAW);
            return map;
        }));
    }
 
    public RockPaperScissors() {
        for(;;) {
            System.out.println("\nRock-Paper-Scissors GO!");
            System.out.println("1: Rock, 2: Paper, 3: Scissors");
            String otherHand = System.console().readLine();
 
            try {
                if (match(otherHand)) {
                    continue;
                }
            } catch (FormatException ex) {
                System.out.println("It's not llegal Hand!\nTry Again!");
                continue;
            }
            
            System.out.println("Continue?: Y or N");
            String answer = System.console().readLine();
            if (!answer.trim().equalsIgnoreCase("y")) {
                System.out.println("Total Win: " + winCount);
                System.out.println("Total Lose: " + loseCount);
                break;
            }
        }
    }
    
    private boolean match(String otherHand) throws FormatException {
        Hand mine = select();
        Hand other = parse(otherHand);
 
        System.out.println("My hand is: " + mine);
        System.out.println("Your hand is: " + other);
 
        Result result = judges.get(mine).judge(other);
        System.out.println(result);
        
        if (result == Result.WIN) {
            winCount++;
        } else if (result == Result.LOSE) {
            loseCount++;
        }
 
        return result == Result.DRAW;
    }
 
    private Hand parse(String hand) throws FormatException {
        try {
            int index = Integer.parseInt(hand);
            if (index > 0 && index < 4) {
                return Hand.values()[index - 1];
            } else {
                throw new FormatException("Illegal Number: " + index);
            }
        } catch (NumberFormatException ex) {
            throw new FormatException(ex);
        }
    }
 
    private Hand select() {
        return Hand.values()[random.nextInt(HAND_SIZE)];
    }
 
    public static void main(String... args) {
        new RockPaperScissors();
    }
}

こちらに移行しました
https://github.com/skrb/RockPaperScissors