Spring Boot 使用 AOP 防止重复提交技术頭條網

在传统的web项目中，防止重复提交，通常做法是：后端生成一个唯一的提交令牌（uuid），并存储在服务端。页面提交请求携带这个提交令牌，后端验证并在第一次验证后删除该令牌，保证提交请求的唯一性。

上述的思路其实没有问题的，但是需要前后端都稍加改动，如果在业务开发完在加这个的话，改动量未免有些大了，本节的实现方案无需前端配合，纯后端处理。

思路

自定义注解 @NoRepeatSubmit 标记所有Controller中的提交请求
通过AOP 对所有标记了 @NoRepeatSubmit 的方法拦截
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，作为一个唯一 KEY，去获取 Redis 分布式锁（如果此时并发获取，只有一个线程会成功获取锁）
业务方法执行后，释放锁

这里只贴出 AOP 类和测试类

@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");
 // 此处可以用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

测试代码如下，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> body = new HashMap<>();
 body.put("userId", userId);
 return new HttpEntity<>(body, headers);
 }
}
/<string>/<string>