The FileChooser class enables users to navigate their local file system to select files for opening or specify destinations for saving. Unlike standard UI controls that reside in javafx.scene.controls, FileChooser belongs to javafx.stage, grouping it with foundational window elements such as Stage, Window, and Popup.

Opening Single and Multiple Files

A FileChooser can present an open dialog for selecting one file or several files simultaneously. Instantiating and displaying the dialog requires specifying the owner window.

FileChooser dialog = new FileChooser();
dialog.setTitle("Select a Document");
File selected = dialog.showOpenDialog(primaryStage);

Typically, the dialog is triggered by a user action like clicking a button rather than appearing automatically at application launch.

import java.awt.Desktop;
import java.io.File;
import java.io.IOException;
import java.util.List;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.FileChooser;
import javafx.stage.Stage;

public class FileOpenerDemo extends Application {

    private final Desktop systemDesktop = Desktop.getDesktop();

    @Override
    public void start(Stage mainWindow) {
        mainWindow.setTitle("File Selection Demo");

        FileChooser chooser = new FileChooser();

        Button pickSingleBtn = new Button("Select One File");
        Button pickManyBtn = new Button("Select Multiple Files");

        pickSingleBtn.setOnAction((ActionEvent evt) -> {
            File result = chooser.showOpenDialog(mainWindow);
            if (result != null) {
                launchFile(result);
            }
        });

        pickManyBtn.setOnAction((ActionEvent evt) -> {
            List<File> results = chooser.showOpenMultipleDialog(mainWindow);
            if (results != null) {
                results.forEach(this::launchFile);
            }
        });

        HBox buttonRow = new HBox(8, pickSingleBtn, pickManyBtn);
        VBox container = new VBox(12, buttonRow);
        container.setPadding(new Insets(15));

        mainWindow.setScene(new Scene(container));
        mainWindow.show();
    }

    private void launchFile(File target) {
        try {
            systemDesktop.open(target);
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    public static void main(String[] args) {
        launch(args);
    }
}

The java.awt.Desktop.open() method opens the selected file with its native application. Platform support for Desktop varies; verify availability using Desktop.isDesktopSupported() before relying on it.

Configuring the Dialog Properties

Customize the browsing experience by defining an initial directory and a descriptive window title. This guides users toward relevant locations immediate.

private void setupChooser(FileChooser chooser) {
    chooser.setTitle("Pick a Resource");
    chooser.setInitialDirectory(new File(System.getProperty("user.home")));
}

Call this configuration method right before invoking showOpenDialog or showOpenMultipleDialog.

Choosing Directories with DirectoryChooser

When the requirement is to select a folder rather than a file, use the DirectoryChooser class from the same javafx.stage package.

Button folderBtn = new Button("Pick a Folder");

folderBtn.setOnAction((ActionEvent evt) -> {
    DirectoryChooser dirPicker = new DirectoryChooser();
    dirPicker.setTitle("Select Destination Folder");
    File chosenFolder = dirPicker.showDialog(mainWindow);
    if (chosenFolder != null) {
        chooser.setInitialDirectory(chosenFolder);
    }
});

The seletced directory can subsequently be assigned as the initialDirectory for a FileChooser, maintaining context between selections.

Filtering File Extensions

Extension filters restrict visible files to specific types, reducing clutter and preventing invalid selections. Add FileChooser.ExtensionFilter instances to the chooser's filter list.

private void applyImageFilters(FileChooser chooser) {
    chooser.setTitle("Browse Pictures");
    chooser.setInitialDirectory(new File(System.getProperty("user.home")));
    chooser.getExtensionFilters().addAll(
        new FileChooser.ExtensionFilter("All Files", "*.*"),
        new FileChooser.ExtensionFilter("JPEG Images", "*.jpg", "*.jpeg"),
        new FileChooser.ExtensionFilter("PNG Images", "*.png")
    );
}

When a user selects a specific filter from the dropdown, only matching files appear in the browsing pane.

Saving Files

The showSaveDialog method presents a standard save dialog, allowing users to name a file and choose a storage location. It returns a File reference representing the chosen path, or null if canceled.

import javafx.embed.swing.SwingFXUtils;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javax.imageio.ImageIO;

// Inside an event handler:
FileChooser saveTool = new FileChooser();
applyImageFilters(saveTool);
saveTool.setTitle("Export Image");

File destination = saveTool.showSaveDialog(mainWindow);
if (destination != null) {
    try {
        ImageIO.write(SwingFXUtils.fromFXImage(imageView.getImage(), null), "png", destination);
    } catch (IOException ex) {
        ex.printStackTrace();
    }
}

The save dialog behaves like a conventional OS save window: the user navigates to a target folder, types a filename, and confirms by clicking Save. Extension filters applied beforehand determine the default file type suggestions.