Discarding garbage characters after json object with Json.Net

问题

I have to consume a so called web service implemented by a dumb monkey which is returning some garbage after the proper Json response. Something like this:

{
  "Property1": 1,
  "Property2": 2,
  "Property3": 3
}<?xml version='1.0' ?>Maybe some other gibberish nonsense I wish to discard.

Now, I could just search for "<?xml" and split, but I was wondering if I can use a stream reader or something to read up to the closing } and then discard the rest.

I'm using C# and Json.Net.

回答1:

You can also set JsonSerializerSettings.CheckAdditionalContent = false to tell the serializer to ignore any content after the end of the deserialized JSON object:

var result = JsonConvert.DeserializeObject<Dictionary<string, long>>(json, new JsonSerializerSettings { CheckAdditionalContent = false })

Oddly enough it is necessary to do this explicitly despite the fact that the default value seems to be false already, since the underlying field is nullable.

回答2:

I knew there had to be a simple and robust way:

    public T ReadTypeAndDiscardTheRest<T>(string json)
    {
        using (var sr = new StringReader(json))
        using (var jsonReader = new JsonTextReader(sr))
        {
            var token = JToken.Load(jsonReader);

            return token.ToObject<T>();
        }
    }

    [Test]
    public void TestJsonDiscarding()
    {
        var json = @"{""Key"":""a"", ""Value"":""n""}<?xml>aaaa";
        var kp = ReadTypeAndDiscardTheRest<KeyValuePair<string, string>>(json);

        Assert.That(kp.Key, Is.EqualTo("a"));
        Assert.That(kp.Value, Is.EqualTo("n"));
    }

As always, Json.Net FTW.

来源：https://stackoverflow.com/questions/37172263/discarding-garbage-characters-after-json-object-with-json-net

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