GSON Tutorial Part 1

Employee.java

package com.codinginflow.gsonexample;

import com.google.gson.annotations.SerializedName;

public class Employee {
    @SerializedName("first_name")
    private String mFirstName;
    @SerializedName("age")
    private int mAge;
    @SerializedName("mail")
    private String mMail;

    public Employee(String firstName, int age, String mail) {
        mFirstName = firstName;
        mAge = age;
        mMail = mail;
    }
}

employee.json

{
  "age": 30,
  "first_name": "John",
  "mail": "john@gmail.com"
}

MainActivity.java

package com.codinginflow.gsonexample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.google.gson.Gson;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Gson gson = new Gson();

        /*
        Employee employee = new Employee("John", 30, "john@gmail.com");
        String json = gson.toJson(employee);
        */

        String json = "{\"first_name\":\"John\",\"age\":30,\"mail\":\"john@gmail.com\"}";
        Employee employee = gson.fromJson(json, Employee.class);
    }
}