C# - How to deal with 404 error in JSON url in JSON.NET

Question

Context

I'm working on a small console application which would allow to input a username of any EUW players on League of Legends and it should try to spectate their games.

The problem

My issue is that I don't really know how I would deal with the JSON file I receive from the Riot API being empty and giving me a 404 error.

The code

Program.cs

var json2 = new WebClient().DownloadString("https://euw1.api.riotgames.com/lol/summoner/v3/summoners/by-name/" + Username);
var summoner = JsonConvert.DeserializeObject<Summoner.RootObject>(json2);
var json = new WebClient().DownloadString("https://euw1.api.riotgames.com/lol/spectator/v3/active-games/by-summoner/" + summoner.id);
var model = JsonConvert.DeserializeObject<Model.RootObject>(json);
long gameid = model.gameId;
string encrypkey = model.observers.encryptionKey;
Spectate(gameid, encrypkey);

Would a simple try-catch suffice? And if so, how would I properly have it attempt the second DeserializeObject based on the success of the first when I can't access the variable summoner outside of the try-catch?

EDIT2: I managed to find a somewhat nice solution that does exactly what I need it to.

bool xd = true;
while (xd == true)
{
    Console.Write("Enter username: ");
    string Username = Console.ReadLine();
    try
    {
        var json2 = new WebClient().DownloadString("https://euw1.api.riotgames.com/lol/summoner/v3/summoners/by-name/" + Username);
        var summoner = JsonConvert.DeserializeObject<Summoner.RootObject>(json2);
        var json = new WebClient().DownloadString("https://euw1.api.riotgames.com/lol/spectator/v3/active-games/by-summoner/" + summoner.id);
        var model = JsonConvert.DeserializeObject<Model.RootObject>(json);
        long gameid = model.gameId;
        string encrypkey = model.observers?.encryptionKey;
        Spectate(gameid, encrypkey);
        xd = false;
        }
        catch (WebException ex)
        {
            if (ex.Status == WebExceptionStatus.ProtocolError && ex.Response != null)
            {
                var resp = (HttpWebResponse)ex.Response;
                if (resp.StatusCode == HttpStatusCode.NotFound)
                {
                    Console.WriteLine("This summoner does not exist or is not in a game");
                    Console.WriteLine("Please try again");
                    continue;
                }
             }
             throw;
        }    
}

@PatrickHofman I think it is not duplicate. The OP not asking for checking null json instead he wants the options of dealing with it. — Amit chauhan, Oct 22 '18 at 11:24
@PatrickHofman Sorry for my incredibly rude post, there's no real justification, just a bit of frustration I guess. I had another look over the post and realized that the formulation of the question and the body text didn't clearly state what it was I needed. Again, sorry. — Matt J, Oct 22 '18 at 13:07
You are welcome, and thanks for understanding the work we do here to moderate. You are one of the few who actually seems to care. No need to be sorry, I didn't think it was rude, the problem just wasn't clear to me. — Patrick Hofman, Oct 22 '18 at 13:09

Amit chauhan · Answer 1 · 2018-10-24T08:42:38.500

Try Catch is not the solution here

Check for Object Nulls before accessing them and there child

Ex -

var json2 = new WebClient().DownloadString("https://euw1.api.riotgames.com/lol/summoner/v3/summoners/by-name/" + Username);
var summoner = JsonConvert.DeserializeObject<Summoner.RootObject>(json2);
var json = new WebClient().DownloadString("https://euw1.api.riotgames.com/lol/spectator/v3/active-games/by-summoner/" + summoner.id);
var model = JsonConvert.DeserializeObject<Model.RootObject>(json);
if(model !=null){   // Checking for null
long gameid = model.gameId;
string encrypkey = model.observers?.encryptionKey;   // Checking for null
}

C# - How to deal with 404 error in JSON url in JSON.NET

1 Answers1