"Open file..." dialog box won't close

Question

Hi, I am new to the Java language. I used Eclipse as my development tool. I have code to open the file dialog box and it did, but I have two problems:

1. When I select the file and click the "Open" button in the dialog box, the dialog box appears again instead of closing.
2. Sometimes the text in filename textbox in the dialog is unclear and/or the text on the button disappears. If I enlarge the dialog, the text will show completely.

Here is my code:

package PDFAnnotationPackage;

import java.awt.event.*;
import javax.swing.*;
import javax.swing.SwingUtilities;
import javax.swing.filechooser.*;
import java.io.*;

public class MainForm extends JFrame implements ActionListener  {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    new MainForm();
}

public MainForm(){
    super("Example");
    addWindowListener(new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
            System.exit(0);
        }
    });

    // Name the JMenu & Add Items
    JMenu menu = new JMenu("File");
    menu.add(makeMenuItem("Open"));
    menu.add(makeMenuItem("Save"));
    menu.add(makeMenuItem("Quit"));

    // Add JMenu bar
    JMenuBar menuBar = new JMenuBar();
    menuBar.add(menu);
    setJMenuBar(menuBar);
    setSize(300, 300);
    setLocation(200, 200);
    setVisible(true);
}

public void actionPerformed(ActionEvent e) {

    // Menu item actions
    String command = e.getActionCommand();

    if (command.equals("Quit")) {
        System.exit(0);
    } else if (command.equals("Open")) {
        // Open menu item action
        JFileChooser fileChooser = new JFileChooser();           
        if (fileChooser.showOpenDialog(MainForm.this) == JFileChooser.APPROVE_OPTION) {
          File file = fileChooser.getSelectedFile();
          System.out.println("Open menu item clicked");
          // load from file
        }
        if (fileChooser.showOpenDialog(this) == JFileChooser.CANCEL_OPTION ) {

            }


        } else if (command.equals("Save")) {
        // Save menu item action
        System.out.println("Save menu item clicked");
        }
    }

    private JMenuItem makeMenuItem(String name) {
        JMenuItem m = new JMenuItem(name);
        m.addActionListener(this);
        return m;
    }
}

How can I solve the issues? Thanks in advance.

Answer 1

Your dialog box appear again because you're calling a method showOpenDialog twice. Try this

if (command.equals("Quit")) {
    // Close application
} else if (command.equals("Open")) {
    JFileChooser fileChooser = new JFileChooser(); 
    int returnVal = fileChooser.showOpenDialog(parent);

    if (returnVal ==  FileChooser.APPROVE_OPTION) {
        File file = fileChooser.getSelectedFile();
        // Load file
    } else if (returnVal == JFileChooser.CANCEL_OPTION ) {
        // Do something else
    } 
} else if (command.equals("Save")) {
    // Save menu item action
}

Answer 2

You're calling fileChooser.showOpenDialog(this) multiple times and that's why your program is behaving as it's behaving. Instead call fileChooser.showOpenDialog(this) once, and save its value to a variable.

In fact, you don't even need this empty block:

if (fileChooser.showOpenDialog(this) == 
    JFileChooser.CANCEL_OPTION ) {
}

So get rid of it!