Below you will find the Java code for creating a simple Swing application.
Swing application to Convert Celsius to Fahrenheit (buttons, input fields and labels)
//package swing; import java.awt.*; import java.awt.event.*; import javax.swing.*; public class Converter implements ActionListener { JFrame frame; JPanel panel; JTextField tempCel; JLabel celLabel, fahLabel, resultFah; JButton changeTemp; public Converter() { //Create and set up the window. frame = new JFrame("Change Celsius to Fahrenheit"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(new Dimension(180, 80)); //Create and set up the panel. panel = new JPanel(new GridLayout(3, 2)); panel.setBorder(BorderFactory.createEmptyBorder(60, //top 60, //left 20, //bottom 60) //right ); //Add the items. addItems(); //Set the default button. frame.getRootPane().setDefaultButton(changeTemp); //Add the panel to the frame. frame.getContentPane().add(panel, BorderLayout.CENTER); //Display the window. frame.pack(); frame.setVisible(true); } private void addItems() { //Create items. tempCel = new JTextField(2); celLabel = new JLabel("Celsius", SwingConstants.LEFT); resultFah = new JLabel("", SwingConstants.LEFT); fahLabel = new JLabel("Fahrenheit", SwingConstants.LEFT); changeTemp = new JButton("Convert"); //Listen to events from the Convert button. changeTemp.addActionListener(this); //Add the items to the container. panel.add(tempCel); panel.add(celLabel); panel.add(resultFah); panel.add(fahLabel); panel.add(changeTemp); celLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5)); fahLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5)); } public void actionPerformed(ActionEvent event) { //Parse degrees Celsius as a double and convert to Fahrenheit. int tempFahr = (int) ((Double.parseDouble(tempCel.getText())) * 1.8 + 32); resultFah.setText(tempFahr + ""); } private static void createAndShowGUI() { //Make sure we have nice window decorations. JFrame.setDefaultLookAndFeelDecorated(true); Converter converter = new Converter(); } public static void main(String[] args) { javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } }