短链接生成实例

　　完成一个短链接转换到存储到访问大致需要做这些工作：DB设计->Helper类->UI->路由。

　　1.数据库设计主要是存储短链接编码及原链接地址，其他一些插入时间等等自由设计。

　　

　　2.封装一个长链接转短链接的类，这边是用了 C#生成短链接 这位博主封装的类，这个也可以自由发挥，主要是取随机数大小写字母与阿拉伯数字。

public class ShortUrlHelper
    {
        /// <summary>
        /// 返回六位数链接编码
        /// </summary>
        /// <param name="url">原链接完整地址</param>
        /// <returns></returns>
        public string GetShortURL(string url)
        {
            //可以自定义生成MD5加密字符传前的混合KEY
            string key = DateTime.Now.ToString();
            //要使用生成URL的字符
            string[] chars = new string[]{
             "a","b","c","d","e","f","g","h",
             "i","j","k","l","m","n","o","p",
             "q","r","s","t","u","v","w","x",
             "y","z","0","1","2","3","4","5",
             "6","7","8","9","A","B","C","D",
             "E","F","G","H","I","J","K","L",
             "M","N","O","P","Q","R","S","T",
             "U","V","W","X","Y","Z"
              };

            //对传入网址进行MD5加密
            string hex = BitConverter.ToString(MD5.Create().ComputeHash(Encoding.Default.GetBytes(key + url))).Replace("-", "");

            string[] resUrl = new string[4];
            for (int i = 0; i < 4; i++)
            {
                //把加密字符按照8位一组16进制与0x3FFFFFFF进行位与运算
                int hexint = 0x3FFFFFFF & Convert.ToInt32("0x" + hex.Substring(i * 8, 8), 16);
                string outChars = string.Empty;
                for (int j = 0; j < 6; j++)
                {
                    //把得到的值与0x0000003D进行位与运算，取得字符数组chars索引
                    int index = 0x0000003D & hexint;
                    //把取得的字符相加
                    outChars += chars[index];
                    //每次循环按位右移5位
                    hexint = hexint >> 5;
                }
                //把字符串存入对应索引的输出数组
                resUrl[i] = outChars;
            }
            return resUrl[new Random().Next(0, 3)];
        }
    }

　　3.页面可以实现用户在链接转换后默认选择文本框内容，用户直接按Ctrl+V复制即可。

@{
    ViewBag.Title = "ShortURL";
}

<form  id="formSearch" name="formSearch" class="form-horizontal col-sm-12 col-xs-12"" action="/SmsOrder/ShortURL" style="float:left">
    <div class="form-group">
        <label class="control-label col-sm-2 col-xs-2" for=""><span style="color: red">*</span>原链接</label>
        <div class="col-xs-10 col-sm-10">
            <input type="text" class="form-control" id="url" name="url" value="@ViewData["url"]"" placeholder="输入链接">
        </div>
    </div>
    <div class="form-group">
        <div style="text-align: center">
            <input type="submit" id="btn_submit1" class="btn btn-primary" value="生成短链接">
        </div>
    </div>
    <div class="form-group">
        <label class="control-label col-sm-2 col-xs-2" for=""><span style="color: red"></span>短链接</label>
        <div class="col-xs-10 col-sm-10">
            <input type="text" class="form-control" id="shorturl" name="shorturl" value="@ViewData["shorturl"]">
        </div>
    </div>
    <div class="form-group">
        <div style="text-align: center; color:red">
            @ViewData["msg"]
        </div>
    </div>
</form>
<script type="text/javascript">
    window.onload = function () {
        var input = document.getElementById("shorturl");
        if (input.value != "") {
            input.focus();
            document.formSearch.shorturl.select();
        }
    }
</script>

　　后台有config配置域名、用户输入链接判断是否能成功访问等操作。

public ActionResult ShortURL(string url)
        {
            string msg = "";
            string shorturl = "";
            string shorturlRealmName = ConfigurationManager.AppSettings["shorturlRealmName"];
            try
            {
                if (!string.IsNullOrEmpty(url))
                {
                    HttpWebResponse response = CreateRequest.CreateGetHttpResponse(url, 0, "", null);
                    if (response.StatusCode == HttpStatusCode.OK)
                    {
                        Sms_URL smsurl = new Sms_URL();
                        smsurl.url = url;
                        smsurl.url_code = new ShortUrlHelper().GetShortURL(url);
                        //唯一测试
                        //smsurl.url_code = "YbiI3e";
                        smsurl.click_number = 0;
                        smsurl.is_delete = 0;
                        smsurl.create_time = DateTime.Now;
                        smsurl.modify_time = DateTime.Now;

                        bool result = _sms_URLService.AddSms_URL(smsurl);
                        if (result)
                        {
                            msg = "请按Ctrl+V复制短链接框内文本";
                            shorturl = shorturlRealmName + smsurl.url_code;
                        }
                    }
                    else
                    {
                        msg = "请输入有效的链接";
                    }

                }
                ViewData["msg"] = msg;
                ViewData["shorturl"] = shorturl;
                ViewData["url"] = url;
                return View();
            }
            catch (Exception ex)
            {
                ViewData["msg"] = "请确定输入的链接有效或重新点击生成短链接";
                ViewData["shorturl"] = "";
                ViewData["url"] = url;
                return View();
            }
        }

　　4.都完成之后配置一个跳转方法。这个方法放哪主要看你域名绑定的项目，我这用的是Api绑定的一个域名，手上项目因为只有api对外方便点。配置路由，因为短链接要的就是短所以只保留 域名/urlcode即可。获取code去表查询原链接，重定向原链接即可

[Route("~/{smscode}")]
        [HttpGet]
        public HttpResponseMessage smsjump(string smscode)
        {
            Sms_URL smsurl = _sms_URLService.GetSms_URLByUrlCode(smscode);
            var response = Request.CreateResponse(HttpStatusCode.Moved);
            if (smsurl == null || smsurl.is_delete == 1)
                return response;
            smsurl.click_number = smsurl.click_number + 1;
            _sms_URLService.UpdateSms_URL(smsurl);
            response.Headers.Location = new Uri(smsurl.url);
            return response;
        }