基于Java设计一个高并发的秒杀系统

// 商品实体类
public class Product {
    private String id;
    private String name;
    private int stock;

    // 省略构造方法和Getter/Setter
}

// 秒杀订单实体类
public class Order {
    private String id;
    private String productId;
    private String userId;
    private Date createTime;

    // 省略构造方法和Getter/Setter
}

// 秒杀服务类
@Service
public class SeckillService {
    private static final int MAX_STOCK = 100; // 商品的最大库存数量

    private final Map<String, Product> products = new ConcurrentHashMap<>(); // 商品信息
    private final Set<String> seckillUsers = new HashSet<>(); // 已秒杀用户

    @PostConstruct
    public void init() {
        // 初始化商品信息
        Product product = new Product("1", "iPhone 12", MAX_STOCK);
        products.put(product.getId(), product);
    }

    // 执行秒杀操作
    public synchronized boolean seckill(String productId, String userId) {
        // 判断商品是否存在
        Product product = products.get(productId);
        if (product == null) {
            return false;
        }

        // 判断商品库存是否足够
        if (product.getStock() <= 0) {
            return false;
        }

        // 判断用户是否已经秒杀过
        if (seckillUsers.contains(userId)) {
            return false;
        }

        // 执行秒杀逻辑
        product.setStock(product.getStock() - 1);
        Order order = new Order(UUID.randomUUID().toString(), productId, userId, new Date());
        // 保存订单信息到数据库或消息队列等
        // ...

        // 添加已秒杀用户
        seckillUsers.add(userId);

        return true;
    }
}

// 秒杀控制器
@RestController
public class SeckillController {
    private final SeckillService seckillService;

    public SeckillController(SeckillService seckillService) {
        this.seckillService = seckillService;
    }

    @PostMapping("/seckill")
    public String seckill(@RequestParam("productId") String productId,
                          @RequestParam("userId") String userId) {
        boolean success = seckillService.seckill(productId, userId);
        if (success) {
            return "秒杀成功";
        } else {
            return "秒杀失败";
        }
    }
}

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.io.IOException;
import java.util.UUID;
import java.util.concurrent.TimeoutException;

public class SeckillProducer {

    private static final String QUEUE_NAME = "seckillQueue";

    public static void main(String[] args) throws IOException, TimeoutException {
        // 创建连接工厂
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setUsername("guest");
        factory.setPassword("guest");

        try (Connection connection = factory.newConnection();
             Channel channel = connection.createChannel()) {
            // 声明队列
            channel.queueDeclare(QUEUE_NAME, false, false, false, null);

            // 模拟秒杀请求
            String productId = "12345";
            String userId = UUID.randomUUID().toString();

            // 发送秒杀消息到队列
            String message = productId + "," + userId;
            channel.basicPublish("", QUEUE_NAME, null, message.getBytes("UTF-8"));
            System.out.println("秒杀消息发送成功：" + message);
        }
    }
}

import com.rabbitmq.client.*;
import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class SeckillConsumer {

    private static final String QUEUE_NAME = "seckillQueue";

    public static void main(String[] args) throws IOException, TimeoutException {
        // 创建连接工厂
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setUsername("guest");
        factory.setPassword("guest");

        // 创建连接
        Connection connection = factory.newConnection();

        // 创建通道
        Channel channel = connection.createChannel();

        // 声明队列
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);

        // 创建消费者
        Consumer consumer = new DefaultConsumer(channel) {
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                String message = new String(body, "UTF-8");
                System.out.println("收到秒杀消息：" + message);

                // 处理秒杀逻辑
                processSeckillMessage(message);

                // 手动确认消息已被消费
                channel.basicAck(envelope.getDeliveryTag(), false);
            }
        };

        // 监听队列并消费消息
        channel.basicConsume(QUEUE_NAME, false, consumer);
    }

    private static void processSeckillMessage(String message) {
        // 解析消息，执行秒杀逻辑
        String[] parts = message.split(",");
        String productId = parts[0];
        String userId = parts[1];

        // 执行秒杀操作
        // ...
    }
}