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redis 实现登陆次数限制的思路详解

2019年09月09日  | 移动技术网IT编程  | 我要评论

title: redis-login-limitation 

利用 redis 实现登陆次数限制, 注解 + aop, 核心代码很简单.

基本思路

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

核心代码

定义一个注解, 用来标识需要登陆次数校验的方法

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...

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<string, string> 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<string, string> 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:

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<loginresp> login(@validated @requestbody loginreq req) {
    return new responseentity<>(sessionservice.login(req), httpstatus.ok);
  }
}

references


总结

以上所述是小编给大家介绍的redis 实现登陆次数限制的思路详解,希望对大家有所帮助

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