import java.io.File;
import java.util.ArrayList;
import java.util.List;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.stage.FileChooser;
import javafx.stage.Stage;


public class Main extends Application {
    public static void main(String[] args) {
        launch(args);        
    }
    
    private static final String[] EXTS = new String[] { ".txt" };
    private static final List<String> EXTS_LIST = new ArrayList<String>();
    
    @Override
    public void start(final Stage stage) {
        EXTS_LIST.add(".txt");
        
        HBox root = new HBox();
        final Scene scene = new Scene(root);
        stage.setWidth(200);
        stage.setHeight(100);
        stage.setScene(scene);

        Button butt1 = new Button("Open");
        butt1.setOnAction(new EventHandler<ActionEvent>() {
            public void handle(ActionEvent e) {
                FileChooser fileChooser = new FileChooser();
                fileChooser.setTitle("Open");

                fileChooser.getExtensionFilters().add(
                        new FileChooser.ExtensionFilter("Text files (.txt)",
                                EXTS));

                File chosenOne;
                if ((chosenOne = fileChooser.showOpenDialog(stage)) != null) {
                    // Do something
                }
            }
        });
        
        Button butt2 = new Button("Save");
        butt2.setOnAction(new EventHandler<ActionEvent>() {
            public void handle(ActionEvent e) {
                FileChooser fileChooser = new FileChooser();
                fileChooser.setTitle("Save");

                fileChooser.getExtensionFilters().add(
                        new FileChooser.ExtensionFilter("Text files (.txt)",
                                EXTS));

                File chosenOne;
                if ((chosenOne = fileChooser.showSaveDialog(stage)) != null) {
                    // Do something
                }
            }
        });
        root.getChildren().addAll(butt1, butt2);
        
        stage.setVisible(true);
    }
}