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.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class MainClass extends JFrame {
private JButton buttonOK = new JButton("OK");
private JTextField textName = new JTextField(15);
public static void main(String[] args) {
new MainClass();
}
public MainClass() {
this.setSize(325, 100);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ButtonListener bl = new ButtonListener();
JPanel panel1 = new JPanel();
panel1.add(new JLabel("Enter your name: "));
panel1.add(textName);
buttonOK.addActionListener(bl);
panel1.add(buttonOK);
this.add(panel1);
this.setVisible(true);
}
private class ButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
if (e.getSource() == buttonOK) {
String name = textName.getText();
if (name.length() == 0) {
JOptionPane.showMessageDialog(MainClass.this, "=0", "", JOptionPane.INFORMATION_MESSAGE);
} else {
JOptionPane.showMessageDialog(MainClass.this, "Good morning " + name, "Salutations",
JOptionPane.INFORMATION_MESSAGE);
}
textName.requestFocus();
}
}
}
}