Converting Json to Class object and Vice Versa Using POJO & Gson

What is a POJO?

A POJO (Plain Old Java Object) is a simple Java class with private fields and public getters/setters, with no special framework dependencies — commonly used to model a JSON structure.

public class User {
    private String name;
    private int age;
    // getters and setters
}

Converting Between JSON and POJO

User user = gson.fromJson(jsonString, User.class);
String json = gson.toJson(user);

Why This Pattern Is Popular

Using POJOs with Gson gives compile-time safety and IDE auto-completion when building or reading payloads, instead of working with loosely-typed Maps or raw strings.