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Embedding JFileChooser

I am trying to add a JFileChooser which selects a parent directory and allows users to input a name for a file. I am aware of the showSaveDialog and showOpenDialog methods, however I don't want to create a new window.

Here's what I have so far:

public class BrowserTest extends JFrame {

    private JPanel contentPane;

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    BrowserTest frame = new BrowserTest();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
    public BrowserTest() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);
        JFileChooser browser = new JFileChooser();
        browser.setFileFilter(new FileFilter() {
            @Override
            public String getDescription() {
                return "A .extension file";
            }
            @Override
            public boolean accept(File f) {
                return f.isDirectory();
            }
        });
        browser.setDialogType(JFileChooser.SAVE_DIALOG);
        browser.setSelectedFile(new File("*.extension"));
        browser.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                final String action = e.getActionCommand();
                if(action.equals(JFileChooser.APPROVE_SELECTION)) {
                    System.out.println("trigger");
                    File f = browser.getCurrentDirectory();
                    System.out.println(f);
                }
                if(action.equals(JFileChooser.CANCEL_SELECTION))
                    JOptionPane.showConfirmDialog(null, "Start without saving?", "No save directory selected.", JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE);
            }
        });
        contentPane.add(browser);
        revalidate();
    }
}

For some reason, pressing the save button only executes System.out.println("trigger"); if I select a file. Is there a way to listen for a save button press directly?

您可以使用以下代码访问文件选择器的默认按钮,然后将您自己的侦听器添加到该按钮:

JButton defaultButton = browser.getUI().getDefaultButton(browser);

As noted, one kludge solution is to recursively iterate through the components of your JFileBrowser until you find the correct component, here a JButton with an action command String "Open".

For example, this method could work:

public static void recursiveComponentSearch(Component c, String actionCommand,
        ActionListener listener) {
    if (c instanceof JButton) {
        JButton button = (JButton) c;

        // TODO: delete the line below
        System.out.printf("Text: \"%s\";  action command: \"%s\"%n", button.getText(),
                button.getActionCommand());

        if (button.getActionCommand().equalsIgnoreCase(actionCommand)) {
            button.addActionListener(listener);
        }
    }

    // recursive search here
    if (c instanceof Container) {
        Container container = (Container) c;
        Component[] components = container.getComponents();
        for (Component component : components) {
            recursiveComponentSearch(component, actionCommand, listener);
        }
    }
}

used like:

ActionListener listener = evt -> System.out.println("Save button here");
String actionCommand = "Open";
recursiveComponentSearch(browser, actionCommand, listener);

I just discovered that the problem was in the line browser.setSelectedFile(new File("*.extension")); . Apparently, this method does not like the asterisk and replacing it with anything else will fix the problem. For example: browser.setSelectedFile(new File("new.extension")); will work as intended.

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