Write a program using swing components to add two numbers. Use text fields for inputs and output. Your program should display the result when the user presses a button.

 Swing simple calculator

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

class Calculator extends JFrame implements ActionListener{

    JLabel l1,l2,l3;

    JTextField t1,t2,t3;

    JButton btn1,btn2;

    public Calculator(){

        l1 = new JLabel("Enter 1st number");

        t1 = new JTextField(20);

        l2 = new JLabel("Enter 2nd number");

        l3 = new JLabel("Result");

        t3 = new JTextField(20);

        btn1= new JButton("+");
        btn2 = new JButton("-");
        t2 = new JTextField(20);

        add(l1);

        add(t1);

        add(l2);

        add(t2);

        add(l3);

        add(t3);

        add(btn1);

        add(btn2);

        setSize(390,390);

        setLayout(new FlowLayout(FlowLayout.LEFT));

        setVisible(true);

        btn1.addActionListener(this);

        btn2.addActionListener(this);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }

    public void actionPerformed (ActionEvent ae){

        String s1,s2;

        s1 =t1.getText();

        s2 = t2.getText();

        int n1,n2,n3;

        n1 = Integer.parseInt(s1);

        n2 = Integer.parseInt(s2);

        if(ae.getSource()==btn1)

            n3 = n1+n2;

        else

            n3 = n1-n2;

        t3.setText(String.valueOf(n3));

    }

    public static void main(String[] args) {
        new Calculator();
    }

}