import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Main extends JFrame {
public Main() {
Box box = new Box(BoxLayout.Y_AXIS);
add(box);
JLabel label = new JLabel("I'm centered");
label.setAlignmentX(JComponent.CENTER_ALIGNMENT);
box.add(Box.createVerticalGlue());
box.add(label);
box.add(Box.createVerticalGlue());
}
public static void main(String[] args) {
Main frame = new Main();
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.setSize(300, 300);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}