springboot扫码登录的简单实现

@GetMapping("/generate")
public BaseResult generate() {
    String code = IdUtil.simpleUUID();
    redisCache.setCacheObject(code, CodeUtils.getUnusedCodeInfo(), 
                              DEFAULT_QR_EXPIRE_SECONDS, TimeUnit.SECONDS);
    return BaseResult.success(GENERATE_SUCCESS, code);
}

getToken() {
    this.codeStatus = 'EMPTY'
    this.tip = '正在获取登录码，请稍等'
    // 有效时间 60 秒
    this.effectiveSeconds = 60
    clearInterval(this.timer)
    request({
        method: 'get',
        url: '/code/generate'
    }).then((response) => {
        // 请求成功, 设置二维码内容, 并更新相关信息
        this.code = `${HOST}/code/scan?code=${response.data}`
        this.codeStatus = 'UNUSED'
        this.tip = '请使用手机扫码登录'
        this.timer = setInterval(this.getTokenInfo, 2000)
    }).catch(() => {
        this.getToken()
    })
}

@GetMapping("/info")
public BaseResult info(String code) {
    CodeVO codeVO = redisCache.getCacheObject(code);
    if (codeVO == null) {
        return BaseResult.success(INVALID_CODE, StringUtils.EMPTY);
    }
    return BaseResult.success(GET_SUCCESS, codeVO);
}

getTokenInfo() {
    this.effectiveSeconds--
    // 二维码过期
    if (this.effectiveSeconds <= 0) {
        this.codeStatus = 'EXPIRE'
        this.tip = '二维码已过期，请刷新'
        return
    }
    // 轮询查询二维码状态
    request({
        method: 'get',
        url: '/code/info',
        params: {
            code: this.code.substr(this.code.indexOf('=') + 1)
        }
    }).then(response => {
        const codeVO = response.data
        // 二维码过期
        if (!codeVO || !codeVO.codeStatus) {
            this.codeStatus = 'EXPIRE'
            this.tip = '二维码已过期，请刷新'
            return
        }
        // 二维码状态为为正在登录
        if (codeVO.codeStatus === 'CONFIRMING') {
            this.username = codeVO.username
            this.avatar = codeVO.avatar
            this.codeStatus = 'CONFIRMING'
            this.tip = '扫码成功，请在手机上确认'
            return
        }
        // 二维码状态为确认登录
        if (codeVO.codeStatus === 'CONFIRMED') {
            clearInterval(this.timer)
            const token = codeVO.token
            store.commit('setToken', token)
            this.$router.push('/home')
            Message.success('登录成功')
            return
        }
    })
}

private BaseResult handleUnusedQr(String code, String token) {
    // 校验 app 端访问传递的 token
    boolean isLegal = JwtUtils.verify(token);
    if (!isLegal) {
        return BaseResult.error(AUTHENTICATioN_FaiLED);
    }
    // 保存用户名、头像信息, 供前端展示
    String username = JwtUtils.getUsername(token);
    CodeVO codeVO = CodeUtils.getConfirminGCodeInfo(username, DEFAULT_AVATAR_URL);
    redisCache.setCacheObject(code, codeVO, DEFAULT_QR_EXPIRE_SECONDS, TimeUnit.SECONDS);
    // 返回登录地址、浏览器、操作系统以及一个临时 token 给 app
    String address = HttpUtils.getRealAddressByIp();
    String browser = HttpUtils.getBrowserName();
    String os = HttpUtils.getOsName();
    String tmpToken = JwtUtils.sign(username);
    // 将临时 token 作为键, 用户名为内容存储在 redis 中
    redisCache.setCacheObject(tmpToken, username, DEFAULT_TEMP_TOKEN_EXPIRE_MINUTES, TimeUnit.MINUTES);
    LoginInfoVO loginInfoVO = new LoginInfoVO(address, browser, os, tmpToken);
    return BaseResult.success(SCAN_SUCCESS, loginInfoVO);
}

private BaseResult handleConfirmingQr(String code, String token) {
    // 使用临时 token 获取用户名, 并从 redis 中删除临时 token
    String username = redisCache.getCacheObject(token);
    if (StringUtils.isBlank(username)) {
        return BaseResult.error(AUTHENTICATION_FAILED);
    }
    redisCache.deleteObject(token);
    // 根据用户名生成正式 token并保存在 redis 中供前端使用
    String fORMalToken = JwtUtils.sign(username);
    CodeVO codeVO = CodeUtils.getConfirmedCodeInfo(username, DEFAULT_AVATAR_URL, formalToken);
    redisCache.setCacheObject(code, codeVO, DEFAULT_QR_EXPIRE_SECONDS, TimeUnit.SECONDS);
    return BaseResult.success(CONFIRM_SUCCESS);
}