title: redis-login-limitation

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

https://github.com/xiaoyureed/redis-login-limitation