Verbesert

package biblio;

import java.awt.FlowLayout;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;

import javax.swing.JButton;
import javax.swing.JFrame;

public class main
{

	public static void main(String[] args)
	{
		frame();

	}

	private static void frame()
	{

			GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
			int scwidth = gd.getDisplayMode().getWidth();
			int scheigth = gd.getDisplayMode().getHeight();
			int frameBreite = scwidth / 2;
			int frameHoehe = scheigth / 2;

			JFrame jf1 = new JFrame("Editor");
			jf1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
			jf1.setLocation(frameBreite-frameBreite/2, frameHoehe-frameHoehe/2);
			jf1.setSize(frameBreite, frameHoehe);
			jf1.setLayout(new FlowLayout());
				//Buttons
				int ButtonAnzahl = 9;

				JButton[] buttons = new JButton[ButtonAnzahl];
				int x=0, y=0;
				for (int i = 0; i <= 8; i++) {
					buttons[i] = new JButton();
						if (i == 1 || i == 4 || i ==7) {
							x =  frameBreite / 3;
						}
						if (i == 2 || i == 5 || i ==8) {
							x =  frameBreite / 3 * 2;
						}
						if (i == 3 || i == 4 || i == 5) {
							y = frameHoehe/3;
						}
						if (i == 6 || i == 7 || i == 8) {
							y = frameHoehe/3 * 2;
						}

					buttons[i].setText("Nummer " + (i + 1));
					buttons[i].setBounds(x, y, frameBreite/3, frameHoehe/3);
					jf1.add(buttons[i]);
					buttons[i].setVisible(true);
				}

			jf1.setVisible(true);
	}

}