Spring Boot 使用 AOP 防止重复提交

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

  1. 自定义注解 @NoRepeatSubmit 标记所有Controller中的提交请求
  2. 通过AOP 对所有标记了 @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,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)
  4. 业务方法执行后,释放锁

关于Redis分布式锁

  • 不了解的同学戳这里 ==> 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,如果是单机的部署的项目可以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,完整代码码云

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
@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

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
@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> body = new HashMap<>();
body.put("userId", userId);
return new HttpEntity<>(body, headers);
}

}

成功防止重复提交,控制台日志如下,可以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

本文作者:殷天文
原文链接:https://www.jianshu.com/p/09860b74658e
版权归作者所有,转载请注明出处
文章标签: Aop, SpringBoot

评论

Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now

×