Building a High‑Performance Java Seckill System with SpringBoot, Redis, and RabbitMQ

Project Overview

This project is a simplified Seckill (flash‑sale) system built with SpringBoot. It implements login, product list, product details, flash‑sale purchase, and order details, using asynchronous ordering, hotspot data caching, and mechanisms to prevent overselling.

Technology Stack

Backend: SpringBoot, MyBatis, MySQL, RabbitMQ, Redis

Frontend: HTML, jQuery, Thymeleaf

Implementation Details

User Password Double MD5 Encryption

First MD5 hash protects the password during network transmission; a second MD5 hash protects the stored password against database theft.

Distributed Session Management

After successful login, a UUID token is stored in Redis as the session key and also placed in a cookie; subsequent requests retrieve the user object from Redis using the token.

Unified Exception Handling

Custom interceptor combined with @ControllerAdvice and @ExceptionHandler captures all exceptions and returns a unified response.

Page and Object Caching

Rendered HTML pages are cached in Redis to reduce server processing. Frequently accessed objects such as user, product, and order are also cached; flash‑sale products are pre‑loaded into Redis at startup.

Page Staticization

Front‑end uses AJAX to fetch data and bind it to the page; after the first load the page and data are cached in the browser.

Memory Flag + Redis Pre‑decrement + RabbitMQ Asynchronous Processing

private Map<Long, Boolean> localOverMap = new HashMap<>();
// check memory flag
boolean over = localOverMap.get(goodsId);
if (over) {
    return Result.error(CodeMsg.MIAO_SHA_OVER);
}
// Redis pre‑decrement
long stock = redisService.decr(GoodsKey.getSeckillGoodsStock, "" + goodsId);
if (stock < 0) {
    localOverMap.put(goodsId, true);
    return Result.error(CodeMsg.MIAO_SHA_OVER);
}
// check duplicate order
SeckillOrder order = orderService.getOrderByUserIdGoodsId(user.getId(), goodsId);
if (order != null) {
    return Result.error(CodeMsg.REPEATE_MIAOSHA);
}
// push to queue
SeckillMessage sm = new SeckillMessage();
sm.setUser(user);
sm.setGoodsId(goodsId);
sender.sendSeckillMessage(sm);

The memory flag reduces Redis calls; Redis pre‑decrements stock at startup; RabbitMQ processes orders asynchronously, allowing the client to poll for the result.

Oversell Prevention

(1) Update SQL only when stock > 0:

update seckill_goods set stock_count = stock_count - 1
where goods_id = #{goodsId} and stock_count > 0

(2) Unique index on user‑id and product‑id prevents a user from buying the same item twice.

(3) Optimistic lock with a version field retries on conflict.

Interface Rate Limiting

Custom @AccessLimit annotation limits the number of requests per user within a time window, e.g., max 5 requests per 5 seconds for logged‑in users.

@AccessLimit(seconds=5, maxCount=5, needLogin=true)
@RequestMapping(value="/path", method=RequestMethod.GET)
@ResponseBody
public Result<String> getSeckillPath(User user, @RequestParam("goodsId") long goodsId) {
    if (user == null) {
        return Result.error(CodeMsg.USER_NO_LOGIN);
    }
    String path = seckillService.createPath(user, goodsId);
    return Result.success(path);
}

Demo Screenshots

Code structure, login page, product list, product details, order details, etc.

Source Code

Download: https://gitee.com/jike11231/sec-kill-product