[Java swing] JFileChooser in Java

July 30, 2014 nguyenvanquan7826 TUT Java swing Leave a response

JFileChooser in Java is an object display frame allows you to open or save the file. It's like this:

open and save file in java

Now we will go as a simple example of open and save files.

Open and save files in java

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package nguyenvanquan7826.JFileChooser;
 
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
 
/**
 * --------------------- @author nguyenvanquan7826 ---------------------
 * ------------------ website: cachhoc.net -------------------
 * ---------- date: Jul 29, 2014 - filename: DemoJFileChooser.java ----------
 */
public class DemoJFileChooser extends JFrame implements ActionListener {
 
    public static String iconOpen = "iconOpen.png";
    public static String iconSave = "iconSave.png";
 
    private JTextArea taLog;
    private JButton btnOpen, btnSave;
    private JFileChooser fc = new JFileChooser();
 
    public DemoJFileChooser() {
        addContent();
        setDisplay();
    }
 
    /**
     * set display for JFrame
     */
    private void setDisplay() {
        setTitle("Demo JFileChooser");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }
 
    /**
     * add content for JFrame, JFrame contain a ButtonPane (contain buttons) and
     * a JTextArea to show something you work
     */
    private void addContent() {
        setLayout(new BorderLayout());
        add(createButtonPanel(), BorderLayout.PAGE_START);
        add(new JScrollPane(taLog = createTextArea(15, 30)),
                BorderLayout.CENTER);
    }
 
    /**
     * create a JPanel contain 2 button (open and save) on TOP of JFrame
     */
    private JPanel createButtonPanel() {
        JPanel panel = new JPanel(new FlowLayout());
        panel.add(btnOpen = createButton("Open file", iconOpen));
        panel.add(btnSave = createButton("Save file", iconSave));
        return panel;
    }
 
    /**
     * create JTextArea
     */
    private JTextArea createTextArea(int row, int col) {
        JTextArea ta = new JTextArea(row, col);
        ta.setWrapStyleWord(true);
        ta.setLineWrap(true);
        return ta;
    }
 
    /**
     * create a JButton with text and icon and add Action for it
     */
    private JButton createButton(String text, String iconLink) {
        ImageIcon icon = createImageIcon(iconLink);
        JButton btn = new JButton(text, icon);
        btn.addActionListener(this);
        return btn;
    }
 
    /**
     * get a icon via link to icon
     */
    private ImageIcon createImageIcon(String iconLink) {
        ImageIcon icon = new ImageIcon(getClass().getResource(iconLink));
        return icon;
    }
 
    /**
     * Handle when you open a file
     */
    private void openFile() {
        int select = fc.showOpenDialog(this);
        if (select == JFileChooser.APPROVE_OPTION) {
            taLog.append("You open " + fc.getSelectedFile().getName());
        } else {
            taLog.append("You cancelled open!");
        }
        taLog.append("\n");
    }
 
    /**
     * Handle when you save a file
     */
    private void saveFile() {
        int select = fc.showSaveDialog(this);
        if (select == JFileChooser.APPROVE_OPTION) {
            taLog.append("You save " + fc.getSelectedFile().getName());
        } else {
            taLog.append("You cancelled save!");
        }
        taLog.append("\n");
    }
 
    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == btnOpen) {
            openFile();
            return;
        }
        if (e.getSource() == btnSave) {
            saveFile();
            return;
        }
    }
 
    public static void main(String[] args) {
        new DemoJFileChooser();
    }
}

In the code above you noticed 2 displayed in order to open and save files are different.

int select = fc.showOpenDialog(this);
int select = fc.showSaveDialog(this);

Next argument JFileChooser.APPROVE_OPTION show that you have accepted “Open” or “Save” file.
The icon save and open you put in the same package as follows:

Open and save files in java

The above example only describes how to use JFileChooser, job Read and write text file or reading object you do offline.

Read more: use JFileChooser, class JFileChooser, java swing