Java serialize and unserialize object

DemoSerialize.java

package com.company;

public class DemoSerialize implements java.io.Serializable
{
    public int a;
    public String b;



    public DemoSerialize(int _a, String _b)
    {
        this.a = _a;
        this.b = _b;
    }
}

serialize_and_unserialize_main.java

package com.company;

import java.io.*;


public class Main {

    public static void main(String[] args)
    {
	// write your code here

        DemoSerialize demoSerialize = new DemoSerialize(12, "abcd");

        var fileName = "object.ser";
        try
        {
            ObjectOutputStream outputStream = new ObjectOutputStream(new FileOutputStream(fileName));

            outputStream.writeObject(demoSerialize);

            outputStream.close();

            System.out.println("object serialized. check file");
        }
        catch (IOException ex)
        {
            ex.printStackTrace();
        }

        DemoSerialize demoSerializeObj = null;
        //try with resources
        try(var fileInput = new FileInputStream(fileName);
            var outputStream = new ObjectInputStream(fileInput)
           )
        {
            demoSerializeObj = (DemoSerialize)outputStream.readObject();

            System.out.println("object deserialize");
            System.out.println("a = " + demoSerializeObj.a);
            System.out.println("b = " + demoSerializeObj.b);
        }
        catch (IOException ioe)
        {
            ioe.printStackTrace();
        }

        catch (ClassNotFoundException cnfeEx)
        {
            cnfeEx.printStackTrace();
        }
    }
}