พื้นฐาน Form และ GUI : JTextField , JLabel , JButton เพื่อรับข้อมูลและแสดงข้อมูล

JTextField txt = new JTextField();
txt.getText(); // for get Text
txt.setText(String); for set Text

JLabel lbl = new JLabel();
lbl.getText(); // for get Text
lbl.setText(String); for set Text

JButton btn = new JButton();
btn.getText(); // for get Text
btn.setText(String); for set Text
btn.addActionListener(new ActionListener() { // for create Event
	public void actionPerformed(ActionEvent e) {
		// Event
	}
});

package com.java.myapp;

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;


public class MyForm extends JFrame {

	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				MyForm form = new MyForm();
				form.setVisible(true);
			}
		});
	}
	
	
	public MyForm() {
            
		// Create Form Frame
		super("ThaiCreate.Com Tutorial");
		setSize(450, 300);
		setLocation(500, 280);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		getContentPane().setLayout(null);
		
		// Input A
		final JTextField numA = new JTextField();
		numA.setBounds(27, 26, 62, 20);
    	getContentPane().add(numA);
		
    	// Label + 
    	JLabel label = new JLabel("+");
    	label.setBounds(99, 29, 13, 14);
    	getContentPane().add(label);
    	
    	// Input B
    	final JTextField numB = new JTextField();
    	numB.setBounds(122, 26, 62, 20);
    	getContentPane().add(numB);
    	
    	// Label Result
     	final JLabel lblResult = new JLabel("Result");
    	lblResult.setBounds(27, 68, 85, 14);
    	getContentPane().add(lblResult);
    	
    	
    	// Button Sum
    	JButton btnSum = new JButton("Sum");
    	btnSum.setBounds(194, 25, 65, 23);
    	btnSum.addActionListener(new ActionListener() {
    		public void actionPerformed(ActionEvent e) {
    			
    			double intA =  Double.valueOf(numA.getText()); // get from Input
    			double intB =  Double.valueOf(numB.getText()); // get from Input
    			
    			double intSum = 0;
    			intSum = intA + intB;
    			
    			lblResult.setText(String.valueOf(intSum)); // assign value
    		}
    	});
    	getContentPane().add(btnSum);

	}

}