Node.js 在express中的root之后使用可选参数传递路由控制

我正在开发一个简单的url缩短应用程序，有以下快捷路由:

app.get('/', function(req, res){
  res.render('index', {
    link: null
  });
});

app.post('/', function(req, res){
  function makeRandom(){
    var text = "";
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

    for( var i=0; i < 3 /*y u looking at me <33??*/; i++ )
      text += possible.charAt(Math.floor(Math.random() * possible.length));
    return text;
  }
  var url = req.body.user.url;
  var key = makeRandom();
  client.set(key, url);
  var link = 'http://50.22.248.74/l/' + key;
  res.render('index', {
    link: link
  });
  console.log(url);
  console.log(key);
});

app.get('/l/:key', function(req, res){
  client.get(req.params.key, function(err, reply){
    if(client.get(reply)){
      res.redirect(reply);
    }
    else{
      res.render('index', {
        link: null
      });
    }
  });
});

我想从我的路由中删除/l/(以缩短我的url)，并使:key参数可选.这样做是否正确:

app.get('/:key?', function(req, res, next){
  client.get(req.params.key, function(err, reply){
    if(client.get(reply)){
      res.redirect(reply);
    }
    else{
      next();
    }
  });
});

app.get('/', function(req, res){
  res.render('index, {
    link: null
  });
});

我不确定是否需要指定我的/号路由是"下一条"路由.但由于我唯一的其他路由是我更新的/后路由，我想它会很好地工作.