Spring Boot 使用 AOP来防止重复提交

思路

1. 自定义注解 @NoRepeatSubmit 标记全部Controller中的提交请求

2. 经过AOP 对全部标记了 @NoRepeatSubmit 的方法拦截

3. 在业务方法执行前，获取当前用户的 token（或者JSessionId）+ 当前请求地址，做为一个惟一 KEY，去获取 Redis 分布式锁（若是此时并发获取，只有一个线程会成功获取锁）

4. 业务方法执行后，释放锁

关于Redis 分布式锁

• 不了解的同窗戳这里 ==> Redis分布式锁的正确实现方式

• 使用Redis 是为了在负载均衡部署，若是是单机的部署的项目能够使用一个线程安全的本地Cache 替代 Redis

Code

这里只贴出 AOP 类和测试类，完整代码见 ==> Gitee

 @Aspect @Component public class RepeatSubmitAspect { ​ private final static Logger LOGGER = LoggerFactory.getLogger(RepeatSubmitAspect.class); ​ @Autowired private RedisLock redisLock; ​ @Pointcut("@annotation(noRepeatSubmit)") public void pointCut(NoRepeatSubmit noRepeatSubmit) { } ​ @Around("pointCut(noRepeatSubmit)") public Object around(ProceedingJoinPoint pjp, NoRepeatSubmit noRepeatSubmit) throws Throwable { int lockSeconds = noRepeatSubmit.lockTime(); ​ HttpServletRequest request = RequestUtils.getRequest(); Assert.notNull(request, "request can not null"); ​ // 此处能够用token或者JSessionId
         String token = request.getHeader("Authorization"); String path = request.getServletPath(); String key = getKey(token, path); String clientId = getClientId(); ​ boolean isSuccess = redisLock.tryLock(key, clientId, lockSeconds); ​ if (isSuccess) { LOGGER.info("tryLock success, key = [{}], clientId = [{}]", key, clientId); // 获取锁成功, 执行进程
 Object result; try { result = pjp.proceed(); ​ } finally { // 解锁
 redisLock.releaseLock(key, clientId); LOGGER.info("releaseLock success, key = [{}], clientId = [{}]", key, clientId); ​ } ​ return result; ​ } else { // 获取锁失败，认为是重复提交的请求
             LOGGER.info("tryLock fail, key = [{}]", key); return new ResultBean(ResultBean.FAIL, "重复请求，请稍后再试", null); } ​ } ​ private String getKey(String token, String path) { return token + path; } ​ private String getClientId() { return UUID.randomUUID().toString(); } ​ }

 

多线程测试

测试代码以下，模拟十个请求并发同时提交

 @Component public class RunTest implements ApplicationRunner { ​ private static final Logger LOGGER = LoggerFactory.getLogger(RunTest.class); ​ @Autowired private RestTemplate restTemplate; ​ @Override public void run(ApplicationArguments args) throws Exception { System.out.println("执行多线程测试"); String url="http://localhost:8000/submit"; CountDownLatch countDownLatch = new CountDownLatch(1); ExecutorService executorService = Executors.newFixedThreadPool(10); ​ for(int i=0; i<10; i++){ String userId = "userId" + i; HttpEntity request = buildRequest(userId); executorService.submit(() -> { try { countDownLatch.await(); System.out.println("Thread:"+Thread.currentThread().getName()+", time:"+System.currentTimeMillis()); ResponseEntity<String> response = restTemplate.postForEntity(url, request, String.class); System.out.println("Thread:"+Thread.currentThread().getName() + "," + response.getBody()); ​ } catch (InterruptedException e) { e.printStackTrace(); } }); } ​ countDownLatch.countDown(); } ​ private HttpEntity buildRequest(String userId) { HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_JSON); headers.set("Authorization", "yourToken"); Map<String, Object> div = new HashMap<>(); div.put("userId", userId); return new HttpEntity<>(div, headers); } ​ }

 

成功防止重复提交，控制台日志以下，能够看到十个线程的启动时间几乎同时发起，只有一个请求提交成功了

结论

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