TextFieldExample.java

import javax.swing.*;
import java.awt.event.*;
public class TextFieldExample implements ActionListener{
	JTextField tf1,tf2,tf3;
 	JButton b1,b2;
	TextFieldExample(){
		JFrame f= new JFrame();
		tf1=new JTextField();
		tf1.setBounds(50,50,150,20);
		tf2=new JTextField();
		tf2.setBounds(50,100,150,20);
		tf3=new JTextField();
		tf3.setBounds(50,150,150,20);tf3.setEditable(false);
		b1=new JButton("+");
		b1.setBounds(50,200,50,50);
		b1.addActionListener(this);
		f.add(tf1);f.add(tf2);f.add(tf3);f.add(b1);
		f.setSize(300,300);
		f.setLayout(null);
		f.setVisible(true);
	}
	public void actionPerformed(ActionEvent e){
		String s1=tf1.getText();
		String s2=tf2.getText();
		int a=Integer.parseInt(s1);
		int b=Integer.parseInt(s2);
		int c=0;
		if(e.getSource()==b1){
			c=a+b;
		}
		String result=String.valueOf(c);
		tf3.setText(result);
	}
	public static void main(String[]args){
		new TextFieldExample();
	}
}