使用java多线程 完成抽奖活动

好的，以下是一个简单的使用Java多线程完成抽奖活动的示例代码：

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class LuckyDraw {

    private List<String> participants;  // 参与者名单
    private List<String> winners;  // 中奖者名单
    private int winnerCount;  // 中奖人数

    public LuckyDraw(List<String> participants, int winnerCount) {
        this.participants = participants;
        this.winners = new ArrayList<>();
        this.winnerCount = winnerCount;
    }

    public void startLuckyDraw() {
        int participantCount = participants.size();
        int threadCount = Math.min(participantCount, winnerCount);  // 线程数不能超过参与者数和中奖人数的较小值
        int participantPerThread = participantCount / threadCount;  // 每个线程抽取的参与者数
        int remainder = participantCount % threadCount;  // 余数，将多余的参与者分配给前面的线程

        // 创建线程池
        List<Thread> threads = new ArrayList<>();
        for (int i = 0; i < threadCount; i++) {
            int start = i * participantPerThread + Math.min(i, remainder);  // 计算该线程开始抽取的参与者的下标
            int end = start + participantPerThread + (i < remainder ? 1 : 0);  // 计算该线程结束抽取的参与者的下标
            threads.add(new Thread(new LuckyDrawTask(start, end)));
        }

        // 启动线程
        for (Thread thread : threads) {
            thread.start();
        }

        // 等待所有线程结束
        for (Thread thread : threads) {
            try {
                thread.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        // 输出中奖者名单
        System.out.println("中奖者名单：");
        for (String winner : winners) {
            System.out.println(winner);
        }
    }

    private class LuckyDrawTask implements Runnable {

        private int start;
        private int end;

        public LuckyDrawTask(int start, int end) {
            this.start = start;
            this.end = end;
        }

        @Override
        public void run() {
            Random random = new Random();
            for (int i = start; i < end && winners.size() < winnerCount; i++) {
                try {
                    Thread.sleep(1000);  // 模拟抽奖过程
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                String participant = participants.get(i);
                if (random.nextBoolean()) {
                    synchronized (winners) {
                        winners.add(participant);
                    }
                }
            }
        }
    }

    public static void main(String[] args) {
        List<String> participants = new ArrayList<>();
        for (int i = 1; i <= 50; i++) {
            participants.add("参与者" + i);
        }
        int winnerCount = 3;
        LuckyDraw luckyDraw = new LuckyDraw(participants, winnerCount);
        luckyDraw.startLuckyDraw();
    }
}

上述代码中，我们通过创建多个线程来并行抽取参与者，并使用`synchronized`关键字来保证中奖者名单的线程安全。同时，我们还使用了`Thread.sleep()`方法来模拟抽奖过程。

在`main`方法中，我们创建了一个包含50个参与者的抽奖活动，并设置中奖人数为3，最终输出中奖者名单。