JFileChooser Example
This JFileChooser example allows the user to open and read a text file, edit it, and then save the file. The class extends a JFrame and implements an ActionListener interface. A menu is placed in the frame and a selection from it is caught by the actionPerformed() method of the listener interface. A method to construct the JFileChooser is then called.
In this JFileChooser example the user has edited some text and is about to save it to file.
// JFileChooser Example
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
class JFileChooserExample extends JFrame implements ActionListener {
private JEditorPane jep = new JEditorPane();
public JFileChooserExample() {
super("Editor");
Container cp = getContentPane( );
cp.add(new JScrollPane(jep), BorderLayout.CENTER);
JMenu menu = new JMenu("File");
menu.add(make("Open")); menu.add(make("Save"));
menu.add(make("Quit"));
JMenuBar menuBar = new JMenuBar();
menuBar.add(menu); setJMenuBar(menuBar);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(200,300);
}
public void actionPerformed(ActionEvent e) {
String ac = e.getActionCommand();
if(ac.equals("Open")) openFile();
else if(ac.equals("Save")) saveFile();
else if(ac.equals("Quit")) System.exit(0);
}
private void openFile() {
JFileChooser jfc = new JFileChooser();
int result = jfc.showOpenDialog(this);
if(result == JFileChooser.CANCEL_OPTION) return;
try {
File file = jfc.getSelectedFile();
BufferedReader br = new BufferedReader(new FileReader(file));
String s=""; int c=0;
while((c=br.read())!=-1) s+=(char)c;
br.close(); jep.setText(s);
} catch (Exception e) {
JOptionPane.showMessageDialog(this,e.getMessage(),
"File error",JOptionPane.ERROR_MESSAGE);}
}
private void saveFile( ) {
JFileChooser jfc = new JFileChooser();
int result = jfc.showSaveDialog(this);
if(result == JFileChooser.CANCEL_OPTION) return;
File file = jfc.getSelectedFile();
try {
BufferedWriter bw = new BufferedWriter(new FileWriter(file));
bw.write(jep.getText());
bw.close();
}
catch (Exception e) {
JOptionPane.showMessageDialog(
this,
e.getMessage(),
"File Error",
JOptionPane.ERROR_MESSAGE
);
}
}
private JMenuItem make(String name) {
JMenuItem m = new JMenuItem(name);
m.addActionListener(this);
return m;
}
public static void main(String[] args) {
new JFileChooserExample().setVisible(true);}
}