Replicating a file system

Question

The goal of this is just to practice. I went off on a self-challenge to replicate something(So the names of the parts can be ignored), I'm not done yet (Though what is here is fully runnable), but have enough code that I thought it could merit taking a moment to examine whether I could be doing anything a cleaner way.

This is the main class:

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.Font;
import java.io.File;
import java.io.FileNotFoundException;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JFileChooser;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import javax.swing.table.TableModel;
public class EditorMain {
 JFileChooser fileChooser = new JFileChooser();
 EditorMain() {
 setUIFont (
 new javax.swing.plaf.FontUIResource("Verdana", Font.ITALIC, 11));
 JFrame frame = new JFrame();
 final int WIDTH = 1000;
 final int HEIGHT = 600;
 JPanel imagePanel = new JPanel();
 imagePanel.setLayout(new GridLayout(0, 3));
 imagePanel.add(new JButton(new ImageIcon("Assets/folder.png")));
 imagePanel.add(new JButton(new ImageIcon("Assets/save.png")));
 imagePanel.add(new JButton(new ImageIcon("Assets/printer.png")));
 JMenuBar menuBar = new JMenuBar();
 JMenu fileMenu = new JMenu("File");
 JMenu editMenu = new JMenu("Edit");
 JMenu helpMenu = new JMenu("Need Help?");
 JMenuItem openMenuItem = new JMenuItem("Open");
 JMenuItem cutMenuItem = new JMenuItem("Cut");
 JMenuItem copyMenuItem = new JMenuItem("Copy");
 JMenuItem pasteMenuItem = new JMenuItem("Paste"); 
 openMenuItem.addActionListener(
 e -> {
 if (fileChooser.showOpenDialog(null) 
 == JFileChooser.APPROVE_OPTION) {
 File file = fileChooser.getSelectedFile();
 }
 }
 );
 fileMenu.add(openMenuItem);
 editMenu.add(cutMenuItem);
 editMenu.add(copyMenuItem);
 editMenu.add(pasteMenuItem);
 // add menus to menubar
 menuBar.add(fileMenu);
 menuBar.add(editMenu);
 menuBar.add(helpMenu);
 // put the menubar on the frame
 frame.setJMenuBar(menuBar);
 frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
 frame.setTitle("Trace Functional Method Specification Input Tool");
 frame.setBounds(0, 0, WIDTH, HEIGHT);
 frame.setLocationRelativeTo(null);
 frame.setLayout(new BorderLayout());
 frame.setVisible(true);
 final JTabbedPane tabbedPane = new JTabbedPane();
 JPanel panel = new JPanel();
 panel.setBounds(0, 0, WIDTH, HEIGHT);
 JTable table = new JTable(new ColorTableModel());
 table.setRowHeight(40);
 JScrollPane jscroll = new JScrollPane(table);
 jscroll.setBounds(0, 0, WIDTH, HEIGHT);
 table.setFillsViewportHeight(true); 
 panel.add(jscroll);
 panel.add(imagePanel);
 panel.setToolTipText("Example of helpful message!");
 ((JComponent) jscroll.getParent()).revalidate();
 tabbedPane.addTab("Input/Output Definition", panel);
 tabbedPane.addTab("Data Type Definition", new JPanel());
 tabbedPane.addTab("Access Methods and Event Descriptors Definition",
 new JPanel());
 tabbedPane.addTab("Auxiliary Functions Definition", new JPanel());
 tabbedPane.addTab("Output Behaviour Specification", new JPanel());
 JPanel header = new JPanel();
 header.setLayout(new GridLayout(2, 0));
 JLabel title = new JLabel("Module Interface Specification");
 title.setFont(new Font("Serif", Font.ITALIC, 20));
 header.add(title);
 header.add(imagePanel);
 tabbedPane.setBounds(0, 0, WIDTH, HEIGHT);
 frame.add(header, BorderLayout.PAGE_START); 
 frame.add(tabbedPane);
 frame.setIconImage(new ImageIcon("Assets/Icon.png").getImage());
 frame.setVisible(true);
 }
 public static void main(String[] args) {
 try {
 for (UIManager.LookAndFeelInfo info : 
 UIManager.getInstalledLookAndFeels()) {
 if ("Nimbus".equals(info.getName())) {
 UIManager.setLookAndFeel(info.getClassName());
 break;
 }
 }
 } catch (Exception e) {
 e.printStackTrace();
 }
 SwingUtilities.invokeLater(EditorMain::new);
 }
 public static void setUIFont(javax.swing.plaf.FontUIResource f) {
 java.util.Enumeration keys = UIManager.getDefaults().keys();
 while (keys.hasMoreElements()) {
 Object key = keys.nextElement();
 Object value = UIManager.get(key);
 if (value != null
 && value instanceof javax.swing.plaf.FontUIResource)
 UIManager.put(key, f);
 }
 }
}

The ColorTableModel class:

import javax.swing.table.AbstractTableModel;
class ColorTableModel extends AbstractTableModel {
 Object rowData[][] = {
 { "", "", Boolean.TRUE, Boolean.FALSE },
 { "","", Boolean.FALSE, Boolean.TRUE }
 };
 String columnNames[] = { "Variable Name", "Data Type" , "Input", "Output"};
 public int getColumnCount() {
 return columnNames.length;
 }
 public String getColumnName(int column) {
 return columnNames[column];
 }
 public int getRowCount() {
 return rowData.length;
 }
 public Object getValueAt(int row, int column) {
 return rowData[row][column];
 }
 public Class getColumnClass(int column) {
 return (getValueAt(0, column).getClass());
 }
 public void setValueAt(Object value, int row, int column) {
 rowData[row][column] = value;
 }
 public boolean isCellEditable(int row, int column) {
 return true;
 }
}

I'd like a general review, with an emphasis on tidying my code/increasing readability.

• Vogel612: A somewhat related github repository which is intended to help implementing filesystems that follow the nio.file api: github.com/fge/java7-fs-base

Answer 1

EditorMain

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComponent;
// ...You get the idea.
import javax.swing.UIManager;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;

At this point, you may as well just do the one * import statement:

import javax.swing.*;

Note that the TableModel import is not on the list of things I said to replace. It's unused, so you should get rid of it. Ditto for java.io.FileNotFoundException.

EditorMain() {

This should probably be public; you very rarely need to use package-private, and this doesn't seem like one of those cases. Especially since the class is public and contains main(String[] args).

You never seem to add click listeners to cut, copy, and pasteMenuItem. I suppose this is because you're in a basic version of the code, but at the very least, add a placeholder comment like

//TODO: Add listeners to these

between openMenuItem and the other three. It'll keep you from forgetting.

JScrollPane jscroll = new JScrollPane(table);

jscroll is a terrible name. Admittedly, there's really not a good name for a JScrollPane wrapper, but what I'd do is something like tableScroller, so it's at least clear what it's wrapped around.

} catch (Exception e) {

This is very often terrible idea. Always catch the most specific exceptions you can, with as many catch blocks as is reasonable -- in this case, you'll want to refer to the UIManager#setLookAndFeel Javadocs. They tend to list the exceptions (at least in my experience) in the same order that you should have list them when writing your try/catch blocks.

javax.swing.plaf.FontUIResource

You use the fully qualified name at least twice. Why not import it at the top?

SwingUtilities.invokeLater(EditorMain::new);

Nothing to criticize here. Just wanted to give you an internet pat-on-the-back for doing this. It's a very good idea to separate graphics and processing.

for (UIManager.LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
 if ("Nimbus".equals(info.getName())) {
 UIManager.setLookAndFeel(info.getClassName());
 break;
 }
}

This took me a couple of seconds to get and a read through the docs -- it might be worth it to add a comment along the lines of

// Use the theme called "Nimbus" if it's installed.

java.util.Enumeration is a raw type; it takes a generic, so you should use it with one. In this case, it'd just be java.util.Enumeration<Object>, but it'll help prevent errors later on if you add the generic now.

In openMenuItem.addActionListener, you never actually used file. I'm assuming that's for later, but I wanted to point it out anyway; I'd add a System.out.println(file.getAbsolutePath()); so you can see that it's the right file.

ColorTableModel

I'd recommend adding a check wherever you access an array with a value from a parameter. While it's not strictly necessary, since trying to call anything out-of-bounds will properly throw an error, getting an ArrayIndexOutOfBounds when it doesn't look like you're accessing an array can be confusing. It's as simple as wrapping it in a try/catch and throwing an IllegalArgumentException if you get an ArrayIndexOutOfBounds -- i.e. something like this:

// Same idea for all of them, so I'm just using `get` as an example.
public Object getValueAt(int row, int column) {
 try {
 rowData[row][column];
 } catch (ArrayIndexOutOfBoundsException e) {
 throw new IllegalArgumentException(String.format(Locale.ENGLISH, "(%s, %s) is an invalid location!", row, column), e);
 }
}

I used String#format because I personally find it nicer to use. Concatenation would work equally well.

public Class getColumnClass(int column) {
 return (getValueAt(0, column).getClass());
}

This should return a Class<?> to conform with AbstractTableModel.