redis 实现登陆次数限制

摘要：利用实现登陆次数限制注解核心代码很简单基本思路比如希望达到的要求是这样在内登陆异常次数达到次锁定该用户那么登陆请求的参数中会有一个参数唯一标识一个比如邮箱手机号用这个参数作为存入对应的为登陆错误的次数类型并设置过期时间为当获取到

比如希望达到的要求是这样: 在 1min 内登陆异常次数达到5次, 锁定该用户 1h

那么登陆请求的参数中, 会有一个参数唯一标识一个 user, 比如 邮箱/手机号/userName

用这个参数作为key存入redis, 对应的value为登陆错误的次数, string 类型, 并设置过期时间为 1min. 当获取到的 value == "4" , 说明当前请求为第 5 次登陆异常, 锁定.

所谓的锁定, 就是将对应的value设置为某个标识符, 比如"lock", 并设置过期时间为 1h

定义一个注解, 用来标识需要登陆次数校验的方法

</>复制代码 
package io.github.xiaoyureed.redispractice.anno;
import java.lang.annotation.*;
@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface RedisLimit {
    /**
     * 标识参数名, 必须是请求参数中的一个
     */
    String identifier();
    /**
     * 在多长时间内监控, 如希望在 60s 内尝试
     * 次数限制为5次, 那么 watch=60; unit: s
     */
    long watch();
    /**
     * 锁定时长, unit: s
     */
    long lock();
    /**
     * 错误的尝试次数
     */
    int times();
}

编写切面, 在目标方法前后进行校验, 处理...

</>复制代码 
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参数中注入 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);
    }
}

这样使用:

</>复制代码 
package io.github.xiaoyureed.redispractice.web;
@RestController
public class SessionResources {
    @Autowired
    private SessionService sessionService;
    /**
     * 1 min 之内尝试超过5次, 锁定 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);
    }
}

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