摘要：利用實現登陸次數限制注解核心代碼很簡單基本思路比如希望達到的要求是這樣在內登陸異常次數達到次鎖定該用戶那么登陸請求的參數中會有一個參數唯一標識一個比如郵箱手機號用這個參數作為存入對應的為登陸錯誤的次數類型并設置過期時間為當獲取到

比如希望達到的要求是這樣: 在 1min 內登陸異常次數達到5次, 鎖定該用戶 1h

那么登陸請求的參數中, 會有一個參數唯一標識一個 user, 比如 郵箱/手機號/userName

用這個參數作為key存入redis, 對應的value為登陸錯誤的次數, string 類型, 并設置過期時間為 1min. 當獲取到的 value == "4" , 說明當前請求為第 5 次登陸異常, 鎖定.

所謂的鎖定, 就是將對應的value設置為某個標識符, 比如"lock", 并設置過期時間為 1h

定義一個注解, 用來標識需要登陸次數校驗的方法

package io.github.xiaoyureed.redispractice.anno;

import java.lang.annotation.*;

@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface RedisLimit {
    /**
     * 標識參數名, 必須是請求參數中的一個
     */
    String identifier();

    /**
     * 在多長時間內監控, 如希望在 60s 內嘗試
     * 次數限制為5次, 那么 watch=60; unit: s
     */
    long watch();

    /**
     * 鎖定時長, unit: s
     */
    long lock();

    /**
     * 錯誤的嘗試次數
     */
    int times();
}

編寫切面, 在目標方法前后進行校驗, 處理...

package io.github.xiaoyureed.redispractice.aop;

@Component
@Aspect
// Ensure that current advice is outer compared with ControllerAOP
// so we can handling login limitation Exception in this aop advice.
//@Order(9)
@Slf4j
public class RedisLimitAOP {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Around("@annotation(io.github.xiaoyureed.redispractice.anno.RedisLimit)")
    public Object handleLimit(ProceedingJoinPoint joinPoint) {
        MethodSignature  methodSignature = (MethodSignature) joinPoint.getSignature();
        final Method     method          = methodSignature.getMethod();
        final RedisLimit redisLimitAnno  = method.getAnnotation(RedisLimit.class);// 貌似可以直接在方法參數中注入 todo

        final String identifier = redisLimitAnno.identifier();
        final long   watch      = redisLimitAnno.watch();
        final int    times      = redisLimitAnno.times();
        final long   lock       = redisLimitAnno.lock();
        // final ServletRequestAttributes att             = (ServletRequestAttributes) RequestContextHolder.currentRequestAttributes();
        // final HttpServletRequest       request         = att.getRequest();
        // final String                   identifierValue = request.getParameter(identifier);

        String identifierValue = null;
        try {
            final Object arg           = joinPoint.getArgs()[0];
            final Field  declaredField = arg.getClass().getDeclaredField(identifier);
            declaredField.setAccessible(true);
            identifierValue = (String) declaredField.get(arg);
        } catch (NoSuchFieldException e) {
            log.error(">>> invalid identifier [{}], cannot find this field in request params", identifier);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
        if (StringUtils.isBlank(identifierValue)) {
            log.error(">>> the value of RedisLimit.identifier cannot be blank, invalid identifier: {}", identifier);
        }

        // check User locked
        final ValueOperations ssOps = stringRedisTemplate.opsForValue();
        final String                          flag  = ssOps.get(identifierValue);
        if (flag != null && "lock".contentEquals(flag)) {
            final BaseResp result = new BaseResp();
            result.setErrMsg("user locked");
            result.setCode("1");
            return new ResponseEntity<>(result, HttpStatus.OK);
        }

        ResponseEntity result;
        try {
            result = (ResponseEntity) joinPoint.proceed();
        } catch (Throwable e) {
            result = handleLoginException(e, identifierValue, watch, times, lock);
        }
        return result;
    }

    private ResponseEntity handleLoginException(Throwable e, String identifierValue, long watch, int times, long lock) {
        final BaseResp result = new BaseResp();
        result.setCode("1");
        if (e instanceof LoginException) {
            log.info(">>> handle login exception...");
            final ValueOperations ssOps = stringRedisTemplate.opsForValue();
            Boolean                               exist = stringRedisTemplate.hasKey(identifierValue);
            // key doesn"t exist, so it is the first login failure
            if (exist == null || !exist) {
                ssOps.set(identifierValue, "1", watch, TimeUnit.SECONDS);
                result.setErrMsg(e.getMessage());
                return new ResponseEntity<>(result, HttpStatus.OK);
            }

            String count = ssOps.get(identifierValue);
            // has been reached the limitation
            if (Integer.parseInt(count) + 1 == times) {
                log.info(">>> [{}] has been reached the limitation and will be locked for {}s", identifierValue, lock);
                ssOps.set(identifierValue, "lock", lock, TimeUnit.SECONDS);
                result.setErrMsg("user locked");
                return new ResponseEntity<>(result, HttpStatus.OK);
            }
            ssOps.increment(identifierValue);
            result.setErrMsg(e.getMessage() + "; you have try " + ssOps.get(identifierValue) + "times.");
        }
        log.error(">>> RedisLimitAOP cannot handle {}", e.getClass().getName());
        return new ResponseEntity<>(result, HttpStatus.OK);
    }
}

這樣使用:

package io.github.xiaoyureed.redispractice.web;

@RestController
public class SessionResources {

    @Autowired
    private SessionService sessionService;

    /**
     * 1 min 之內嘗試超過5次, 鎖定 user 1h
     */
    @RedisLimit(identifier = "name", watch = 30, times = 5, lock = 10)
    @RequestMapping(value = "/session", method = RequestMethod.POST)
    public ResponseEntity login(@Validated @RequestBody LoginReq req) {
        return new ResponseEntity<>(sessionService.login(req), HttpStatus.OK);
    }
}

https://github.com/xiaoyureed...