Node.js：Mongoose 的内部服务器错误

Question

I have this web app that is for sharing photos.

Now I have this route that is supposed to return the photos of all the users from the following array.

Route:

router.get('/getphotos',function(req, res){
    var reqPhotos = [];
    console.log( "\n" + req.body.username + "\n");
    try{
      for(x =0; x < req.body.following.length;  x++){
        reqPhotos.push({username: req.body.following[x].username});
      }
    }

    catch(err){
      console.log(err);
    }

    Photo.find({username: reqPhotos}).exec(function(err, allPhotos){
        if(err){console.log(err);}
        else{
          res.json(allPhotos);
        }
    });

});

However, it gives me an internal server error. I get a 500 from the server.

Why does this happen and how to fix it?

Thanks!

EDIT:

I have found out that the req.body.following was undefined. This is how I was calling it using angular:

        $scope.getPhotos = function(){

            if($scope.identification){
                flng = angular.copy($scope.identification.following);
                flng.push($scope.identification.username);
                var data = {username: $scope.identification.username, token: $scope.identification.token, following: flng}
            //IDENTIFICATION HAS ALL THE INFO.
            $http.get('/users/getphotos', data).success(function(response){
                $scope.photos = response;
            });
            }
        }

Answer 1

try with:

router.get('/getphotos',function(req, res){
    var reqPhotos = [];
    for(x =0; x < req.body.following.length;  x++){
      reqPhotos.push({username: req.body.following[x].username});
    }
    Photo.find().where('username').in(reqPhotos).exec(function(err, allPhotos){
        if(err){console.log(err);}
        else{
          res.json(allPhotos);
        }
    });

});