Line delimited json serializing and de-serializing

Question

I am using JSON.NET and C# 5. I need to serialize/de-serialize list of objects into line delimited json. http://en.wikipedia.org/wiki/Line_Delimited_JSON. Example,

{"some":"thing1"}
{"some":"thing2"}
{"some":"thing3"}

and

{"kind": "person", "fullName": "John Doe", "age": 22, "gender": "Male", "citiesLived": [{ "place": "Seattle", "numberOfYears": 5}, {"place": "Stockholm", "numberOfYears": 6}]}
{"kind": "person", "fullName": "Jane Austen", "age": 24, "gender": "Female", "citiesLived": [{"place": "Los Angeles", "numberOfYears": 2}, {"place": "Tokyo", "numberOfYears": 2}]}

Why I needed because its Google BigQuery requirement https://cloud.google.com/bigquery/preparing-data-for-bigquery

Update: One way I found is that serialize each object seperataly and join in the end with new-line.

Answer 1

You can do so by manually parsing your JSON using JsonTextReader and setting the SupportMultipleContent flag to true.

If we look at your first example, and create a POCO called Foo:

public class Foo
{
    [JsonProperty("some")]
    public string Some { get; set; }
}

This is how we parse it:

var json = "{\"some\":\"thing1\"}\r\n{\"some\":\"thing2\"}\r\n{\"some\":\"thing3\"}";
var jsonReader = new JsonTextReader(new StringReader(json))
{
    SupportMultipleContent = true // This is important!
};

var jsonSerializer = new JsonSerializer();
while (jsonReader.Read())
{
    Foo foo = jsonSerializer.Deserialize<Foo>(jsonReader);
}

If you want list of items as result simply add each item to a list inside the while loop to your list.

listOfFoo.Add(jsonSerializer.Deserialize<Foo>(jsonReader));

Note: with Json.Net 10.0.4 and later same code also supports comma separated JSON entries see How to deserialize dodgy JSON (with improperly quoted strings, and missing brackets)?)