JFileChooser is a part of java Swing package. The java Swing package is part of JavaTM Foundation Classes(JFC) . JFC contains many features that help in building graphical user interface in java . Java Swing provides components such as buttons, panels, dialogs, etc . JFileChooser is a easy and an effective way to prompt the user to choose a file or a directory .
In this article we will see how to use JFileChooser in java swing .
Constructors of JFileChooser are :
1. JFileChooser() – empty constructor that points to user’s default directory
// Using this process to invoke the constructor, // JFileChooser points to user's default directory JFileChooser j = new JFileChooser();
// Open the save dialog j.showSaveDialog( null );
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Output of the code snippet:
2. JFileChooser(String) – uses the given path
// Using this process to invoke the constructor, // JFileChooser points to the mentioned path JFileChooser j = new JFileChooser( "d:" );
// Open the save dialog j.showSaveDialog( null );
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Output of the code snippet:
3. JFileChooser(File) – uses the given File as the path
// Using this process to invoke the constructor, // JFileChooser points to the mentioned path // of the file passed JFileChooser j = new JFileChooser( new File( "C:\\Users\\pc\\Documents\\New folder\\" ));
// Open the save dialog j.showSaveDialog( null );
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Output of the code snippet:
4. JFileChooser(FileSystemView) – uses the given FileSystemView
// In this process argument passed // is an object of File System View JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView());
// Open the save dialog j.showSaveDialog( null );
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Output of the code snippet:
5. JFileChooser(String, FileSystemView) – uses the given path and the FileSystemView
// In this process argument passed is an object // of File System View, and a path JFileChooser j = new JFileChooser( "d:" , FileSystemView.getFileSystemView());
// Open the save dialog j.showSaveDialog( null );
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Output of the code snippet:
6. JFileChooser(File, FileSystemView) – uses the given current directory and the FileSystemView
// In this process argument passed is an object // of File System View and a object of // File class File f = new File( "C:\\Users\\pc\\Documents\\New folder\\" );
JFileChooser j = new JFileChooser(f, FileSystemView.getFileSystemView());
// Open the save dialog j.showSaveDialog( null );
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Output of the code snippet:
Note : The code given above are code snippets not the full code, the code snippets given above should be used to invoke the constructor as per the need and discretion of the programmer, the paths mentioned above are arbitrary. User should set the path according to their need.
Practical Applications of JFileChooser
The following codes will not execute in an online compiler. Please use an offline IDE
1. Creating an open or save dialog using JFileChooser
// Java program to create open or // save dialog using JFileChooser import java.io.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.filechooser.*;
class filechooser extends JFrame implements ActionListener {
// Jlabel to show the files user selects
static JLabel l;
// a default constructor
filechooser()
{
}
public static void main(String args[])
{
// frame to contains GUI elements
JFrame f = new JFrame( "file chooser" );
// set the size of the frame
f.setSize( 400 , 400 );
// set the frame's visibility
f.setVisible( true );
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// button to open save dialog
JButton button1 = new JButton( "save" );
// button to open open dialog
JButton button2 = new JButton( "open" );
// make an object of the class filechooser
filechooser f1 = new filechooser();
// add action listener to the button to capture user
// response on buttons
button1.addActionListener(f1);
button2.addActionListener(f1);
// make a panel to add the buttons and labels
JPanel p = new JPanel();
// add buttons to the frame
p.add(button1);
p.add(button2);
// set the label to its initial value
l = new JLabel( "no file selected" );
// add panel to the frame
p.add(l);
f.add(p);
f.show();
}
public void actionPerformed(ActionEvent evt)
{
// if the user presses the save button show the save dialog
String com = evt.getActionCommand();
if (com.equals( "save" )) {
// create an object of JFileChooser class
JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
// invoke the showsSaveDialog function to show the save dialog
int r = j.showSaveDialog( null );
// if the user selects a file
if (r == JFileChooser.APPROVE_OPTION)
{
// set the label to the path of the selected file
l.setText(j.getSelectedFile().getAbsolutePath());
}
// if the user cancelled the operation
else
l.setText( "the user cancelled the operation" );
}
// if the user presses the open dialog show the open dialog
else {
// create an object of JFileChooser class
JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
// invoke the showsOpenDialog function to show the save dialog
int r = j.showOpenDialog( null );
// if the user selects a file
if (r == JFileChooser.APPROVE_OPTION)
{
// set the label to the path of the selected file
l.setText(j.getSelectedFile().getAbsolutePath());
}
// if the user cancelled the operation
else
l.setText( "the user cancelled the operation" );
}
}
} |
2. Use JFileChooser to select directory only
// Java program to use JFileChooser // to select directory only import java.io.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.filechooser.*;
class filechooser extends JFrame implements ActionListener {
// Jlabel to show the files user selects
static JLabel l;
// a default constructor
filechooser()
{
}
public static void main(String args[])
{
// frame to contains GUI elements
JFrame f = new JFrame( "file chooser to select directories" );
// set the size of the frame
f.setSize( 400 , 400 );
// set the frame's visibility
f.setVisible( true );
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// button to open save dialog
JButton button1 = new JButton( "save" );
// button to open open dialog
JButton button2 = new JButton( "open" );
// make an object of the class filechooser
filechooser f1 = new filechooser();
// add action listener to the button to capture user
// response on buttons
button1.addActionListener(f1);
button2.addActionListener(f1);
// make a panel to add the buttons and labels
JPanel p = new JPanel();
// add buttons to the frame
p.add(button1);
p.add(button2);
// set the label to its initial value
l = new JLabel( "no file selected" );
// add panel to the frame
p.add(l);
f.add(p);
f.show();
}
public void actionPerformed(ActionEvent evt)
{
// if the user presses the save button show the save dialog
String com = evt.getActionCommand();
if (com.equals( "save" )) {
// create an object of JFileChooser class
JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
// set the selection mode to directories only
j.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
// invoke the showsSaveDialog function to show the save dialog
int r = j.showSaveDialog( null );
if (r == JFileChooser.APPROVE_OPTION) {
// set the label to the path of the selected directory
l.setText(j.getSelectedFile().getAbsolutePath());
}
// if the user cancelled the operation
else
l.setText( "the user cancelled the operation" );
}
// if the user presses the open dialog show the open dialog
else {
// create an object of JFileChooser class
JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
// set the selection mode to directories only
j.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
// invoke the showsOpenDialog function to show the save dialog
int r = j.showOpenDialog( null );
if (r == JFileChooser.APPROVE_OPTION) {
// set the label to the path of the selected directory
l.setText(j.getSelectedFile().getAbsolutePath());
}
// if the user cancelled the operation
else
l.setText( "the user cancelled the operation" );
}
}
} |
3. Use JFileChooser to allow multiple selection of files
// Java program to use JFileChooser to allow multiple selection of files import java.io.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.filechooser.*;
class filechooser extends JFrame implements ActionListener {
// Jlabel to show the files user selects
static JLabel l;
// a default constructor
filechooser()
{
}
public static void main(String args[])
{
// frame to contains GUI elements
JFrame f = new JFrame( "file chooser to select multiple files at a time" );
// set the size of the frame
f.setSize( 400 , 400 );
// set the frame's visibility
f.setVisible( true );
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// button to open save dialog
JButton button1 = new JButton( "save" );
// button to open open dialog
JButton button2 = new JButton( "open" );
// make an object of the class filechooser
filechooser f1 = new filechooser();
// add action listener to the button to capture user
// response on buttons
button1.addActionListener(f1);
button2.addActionListener(f1);
// make a panel to add the buttons and labels
JPanel p = new JPanel();
// add buttons to the frame
p.add(button1);
p.add(button2);
// set the label to its initial value
l = new JLabel( "no file selected" );
// add panel to the frame
p.add(l);
f.add(p);
f.show();
}
public void actionPerformed(ActionEvent evt)
{
// if the user presses the save button show the save dialog
String com = evt.getActionCommand();
if (com.equals( "save" )) {
// create an object of JFileChooser class
JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
// allow multiple file selection
j.setMultiSelectionEnabled( true );
// invoke the showsSaveDialog function to show the save dialog
int r = j.showSaveDialog( null );
if (r == JFileChooser.APPROVE_OPTION) {
// get the Selected files
File files[] = j.getSelectedFiles();
int t = 0 ;
// set text to blank
l.setText( "" );
// set the label to the path of the selected files
while (t++ < files.length)
l.setText(l.getText() + " " + files[t - 1 ].getName());
}
// if the user cancelled the operation
else
l.setText( "the user cancelled the operation" );
}
// if the user presses the open dialog show the open dialog
else {
// create an object of JFileChooser class
JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
// allow multiple file selection
j.setMultiSelectionEnabled( true );
// invoke the showsOpenDialog function to show the save dialog
int r = j.showOpenDialog( null );
if (r == JFileChooser.APPROVE_OPTION) {
// get the Selected files
File files[] = j.getSelectedFiles();
// set text to blank
l.setText( "" );
int t = 0 ;
// set the label to the path of the selected files
while (t++ < files.length)
l.setText(l.getText() + " " + files[t - 1 ].getName());
}
// if the user cancelled the operation
else
l.setText( "the user cancelled the operation" );
}
}
} |
4. Use JFileChooser to restrict the type of files shown to the user
// Java program to use JFileChooser to restrict // the type of files shown to the user import java.io.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.filechooser.*;
class filechooser extends JFrame implements ActionListener {
// Jlabel to show the files user selects
static JLabel l;
// a default constructor
filechooser()
{
}
public static void main(String args[])
{
// frame to contains GUI elements
JFrame f = new JFrame( "file chooser" );
// set the size of the frame
f.setSize( 400 , 400 );
// set the frame's visibility
f.setVisible( true );
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// button to open save dialog
JButton button1 = new JButton( "save" );
// button to open open dialog
JButton button2 = new JButton( "open" );
// make an object of the class filechooser
filechooser f1 = new filechooser();
// add action listener to the button to capture user
// response on buttons
button1.addActionListener(f1);
button2.addActionListener(f1);
// make a panel to add the buttons and labels
JPanel p = new JPanel();
// add buttons to the frame
p.add(button1);
p.add(button2);
// set the label to its initial value
l = new JLabel( "no file selected" );
// add panel to the frame
p.add(l);
f.add(p);
f.show();
}
public void actionPerformed(ActionEvent evt)
{
// if the user presses the save button show the save dialog
String com = evt.getActionCommand();
if (com.equals( "save" )) {
// create an object of JFileChooser class
JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
// restrict the user to select files of all types
j.setAcceptAllFileFilterUsed( false );
// set a title for the dialog
j.setDialogTitle( "Select a .txt file" );
// only allow files of .txt extension
FileNameExtensionFilter restrict = new FileNameExtensionFilter( "Only .txt files" , "txt" );
j.addChoosableFileFilter(restrict);
// invoke the showsSaveDialog function to show the save dialog
int r = j.showSaveDialog( null );
// if the user selects a file
if (r == JFileChooser.APPROVE_OPTION)
{
// set the label to the path of the selected file
l.setText(j.getSelectedFile().getAbsolutePath());
}
// if the user cancelled the operation
else
l.setText( "the user cancelled the operation" );
}
// if the user presses the open dialog show the open dialog
else {
// create an object of JFileChooser class
JFileChooser j = new JFileChooser(FileSystemView.getFileSystemView().getHomeDirectory());
// restrict the user to select files of all types
j.setAcceptAllFileFilterUsed( false );
// set a title for the dialog
j.setDialogTitle( "Select a .txt file" );
// only allow files of .txt extension
FileNameExtensionFilter restrict = new FileNameExtensionFilter( "Only .txt files" , "txt" );
j.addChoosableFileFilter(restrict);
// invoke the showsOpenDialog function to show the save dialog
int r = j.showOpenDialog( null );
// if the user selects a file
if (r == JFileChooser.APPROVE_OPTION) {
// set the label to the path of the selected file
l.setText(j.getSelectedFile().getAbsolutePath());
}
// if the user cancelled the operation
else
l.setText( "the user cancelled the operation" );
}
}
} |
NOTE :
you can also customize the approve button by using the function setApproveButtonText(String) . This will set the text of the approved button
to the desired text.