import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Main extends JPanel {
public void paint(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
AffineTransform at = new AffineTransform();
at.setToRotation(-Math.PI / 2.0, getWidth() / 2.0, getHeight() / 2.0);
g2d.setTransform(at);
g2d.drawString("Vertical text", 10, 10);
}
public static void main(String[] a) {
JFrame f = new JFrame();
f.add(new Main());
f.setSize(300, 300);
f.setVisible(true);
}
}