用Java代码实现马匹赛跑

　　下面是一个基于Java多线程的赛马游戏示例，该示例中有5匹赛马，每匹赛马都是一个线程。每匹赛马都有一个速度和一个起跑线的位置，他们将在屏幕上移动，直到达到终点线。

import java.util.Random;

public class Horse implements Runnable {
    private static int counter = 0;
    private final int id = counter++;
    private int strides = 0;
    private static Random rand = new Random();
    private static final int FINISH_LINE = 75;
    private Race race;

    public Horse(Race race) {
        this.race = race;
    }

    public synchronized int getStrides() {
        return strides;
    }

    @Override
    public void run() {
        try {
            while(!Thread.interrupted()) {
                synchronized(this) {
                    strides += rand.nextInt(3);
                }
                Thread.sleep(200);
                race.printHorses();
                if(strides >= FINISH_LINE) {
                    race.win(this);
                    return;
                }
            }
        } catch(InterruptedException e) {
            System.out.println("Horse " + id + " interrupted");
        }
    }

    @Override
    public String toString() {
        return "Horse " + id;
    }
}

public class Race {
    private Horse[] horses;
    private int numHorses;
    private static final int FINISH_LINE = 75;
    private volatile Horse winner;

    public Race(int numHorses) {
        this.numHorses = numHorses;
        horses = new Horse[numHorses];
        for(int i = 0; i < numHorses; i++) {
            horses[i] = new Horse(this);
        }
    }

    public void startRace() {
        System.out.println("Starting the race...");
        for(Horse horse : horses) {
            new Thread(horse).start();
        }
    }

    public void win(Horse horse) {
        synchronized(this) {
            if(winner == null) {
                winner = horse;
                System.out.println("Winner: " + winner);
            }
        }
    }

    public void printHorses() {
        for(int i = 0; i < 10; i++) {
            System.out.println();
        }
        for(int i = 0; i < numHorses; i++) {
            System.out.print(horses[i] + ": ");
            for(int j = 0; j < horses[i].getStrides(); j++) {
                System.out.print("*");
            }
            System.out.println();
        }
        try {
            Thread.sleep(15);
        } catch(InterruptedException e) {
            System.out.println("Interrupted while printing horses");
        }
    }
}

public class RacingGame {
    public static void main(String[] args) {
        Race race = new Race(5);
        race.startRace();
    }
}

　　在这个示例中，每匹马都有一个随机生成的速度，每次移动一定的步数。每匹马都有一个起跑线的位置，当它们越过终点线时，会触发一个“胜利”的方法，并且在控制台上输出获胜马匹的信息。

　　在'Race'类中，'startRace()'方法启动每个马匹线程，每个线程都运行一个'Horse'。