在splitPane

Question

我的代码有点麻烦。我已经放入文件选择器/阅读器，但我不知道如何在GUI中的左窗格中显示它。我尝试了一些事情没有成功，无法弄明白。如果有人能够提供解决方案和解释，以便我能够理解我做错了/没做过什么，那么我将非常感激。

此外，我的代码有点凌乱，而且我已经完成了我的方法，如果有人在组织方法和代码方面有未来的部队，那么做某些令人烦恼和不方便的事情会受到高度赞赏。

这是我的代码。

public class JavaAssignment {

    public static JMenuBar setupMenu() { // method modifiers where mising here

        JMenuBar menuBar = new JMenuBar(); // menubar
        JMenu menu1 = new JMenu("File"); //menu 
        menuBar.add(menu1); // add menu to gui
        JMenu menu2 = new JMenu("Help");
        menuBar.add(menu2);
        JMenuItem menuItem1 = new JMenuItem("Load File", KeyEvent.VK_1); // create drop down menu
        JMenuItem menuItem2 = new JMenuItem("Save File", KeyEvent.VK_1);
        JMenuItem menuItem3 = new JMenuItem("Exit", KeyEvent.VK_1);     
        JMenuItem menuItem4 = new JMenuItem("About", KeyEvent.VK_1);

        menu1.add(menuItem1); // adds drop down menus to gui
        menu1.add(menuItem2);
        menu1.add(menuItem3);
        menu2.add(menuItem4);

        // execute code when selected
        menuItem1.addActionListener(new ActionListener() {


            @Override
            public void actionPerformed(ActionEvent e) {

                final JFileChooser fc = new JFileChooser();

                // you can set the directory with the setCurrentDirectory method.
                int returnVal = fc.showOpenDialog(null);

                if (returnVal == JFileChooser.APPROVE_OPTION) {
                    // User has selected to open the file.

                    File file = fc.getSelectedFile();

                    try {
                        // Open the selected file
                        BufferedReader reader = new BufferedReader(new FileReader(file));

                        // Output the contents to the console.
                        String nextLine = reader.readLine();

                        while ( nextLine != null ) {

                            final JTextArea input = new JTextArea(nextLine);
                            nextLine = reader.readLine();
                        }

                        reader.close();

                    } catch (IOException e1) {

                        System.err.println("Error while reading the file");
                    } 


                }
            }});

        return menuBar;
    }

    public static void main(String[] args) throws FileNotFoundException {

        window window = new window();


    }

    public static class window extends JFrame {

        public window() throws FileNotFoundException {

            JScrollPane leftScrollPane = new JScrollPane();
            JPanel rightPane = new JPanel();
            JSplitPane splitPane;

            this.setVisible(true);
            this.setSize(400, 400);
            this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            splitPane = new JSplitPane();
            splitPane.setOrientation(JSplitPane.HORIZONTAL_SPLIT);
            splitPane.setDividerSize(10);
            splitPane.setDividerLocation(100);
            splitPane.setLeftComponent(leftScrollPane);
            splitPane.setRightComponent(rightPane);
            splitPane.setOneTouchExpandable(true);
            splitPane.setDividerLocation(600);

            Dimension minimumSize = new Dimension(100, 50);

            leftScrollPane.setSize(400, 400);

            this.setJMenuBar(setupMenu());
            splitPane.setPreferredSize(new Dimension(400, 200));
            splitPane.setLeftComponent(leftScrollPane);
            splitPane.setRightComponent(rightPane);
            this.add(splitPane);
            this.setSize(1280, 720);
        }
    }
}