How to use System.Text.Json in .NET

Why We Need JSON Handlers

We have multiple formats to represent data but JSON has got the big fan following , it is extensively used for sending-receiving data in applications. It is easy to read and flexible , but to work our application properly we need something that can convert the data into forms which are easy to understand by us and compatible with our data models. That’s where JSON handlers come.

Famous Names in JSON Handling World

We have two libraries that have downloads in billions at Nuget Package Manager :

• Newtonsoft.Json (3.07B Downloads)
• System.Text.Json (1.01B Downloads)

I have covered first one in my LinkedIn Post , today we are going to explore System.Text.Json which is owned by Microsoft.

How to use System.Text.Json

Install Nuget Package System.Text.Json and use it BINGO! Let’s see simple demonstration.

using System.Text.Json;

var dotnetNewsletter = new Newsletter
{
    Name = "Waseem Newsletter",
    Category = ".NET",
    IssuesPerMonth = 4
};

string json = JsonSerializer.Serialize(dotnetNewsletter);

var newsletter = JsonSerializer.Deserialize<Newsletter>(json);

public class Newsletter
{
    public string Name { get; set; } = string.Empty;
    public string Category { get; set; } = string.Empty;
    public int IssuesPerMonth { get; set; }
}

It has got some nice attributes as well that can be helpful , let’s see few of them

JsonRequired Attribute

using System.Text.Json;
using System.Text.Json.Serialization;

string json = "{\"Name\":\"Waseem Newsletter\",\"Category\":\".NET\"}";
// Throws JsonException because requested prop is missing
var newsletter = JsonSerializer.Deserialize<Newsletter>(json);

public class Newsletter
{
    public string Name { get; set; } = string.Empty;
    public string Category { get; set; } = string.Empty;

    [JsonRequired]
    public int IssuesPerMonth { get; set; }
}

JsonPropertyName Attribute

using System.Text.Json;
using System.Text.Json.Serialization;

var newsletter = new Newsletter
{
    Name = "C# Corner",
    Category = "Programming",
    IssuesPerMonth = 12
};

string json = JsonSerializer.Serialize(newsletter);
// {"NewsletterName":"C# Corner", "Category": "Programming", "IssuesPerMonth":12}
Console.WriteLine(json);

class Newsletter
{
    [JsonPropertyName("NewsletterName")]
    public string Name { get; set; } = string.Empty;

    public string Category { get; set; } = string.Empty;

    public int IssuesPerMonth { get; set; }
}

On similar fashion it has got few more attributes as well that you can explore

• JsonIgnore
• JsonConverter

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