MainGUI.java

package notenmanager;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;
import java.awt.*;

public class MainGUI extends JFrame {

	public MainGUI() {
		setTitle("Notenmanager");
		setSize(960, 540);
		setLocationRelativeTo(null);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
		Container pane = getContentPane();
		GroupLayout groupLayout = new GroupLayout(pane);
		pane.setLayout(groupLayout);
		
		JButton	button = new JButton("Test");
		button.addActionListener(new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
				System.out.println("TEST erfolgreich");	
			}
		});
		
		groupLayout.setVerticalGroup(groupLayout.createSequentialGroup().addComponent(button));
		groupLayout.setHorizontalGroup(groupLayout.createSequentialGroup().addComponent(button));
		
		groupLayout.setAutoCreateContainerGaps(true);
	}
	
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			@Override
			public void run() {
				MainGUI main = new MainGUI();
				main.setVisible(true);
			}
		});
	}

}