在JavaFX中，可以使用Lambda表达式和命令模式来实现给按钮添加功能。下面是一个示例代码：
首先定义一个接口Command，该接口包含了要执行的操作：
public interface Command {void execute();}
然后创建两个类：OpenFileCommand和SaveFileCommand，分别表示打开文件和保存文件的操作。
public class OpenFileCommand implements Command {private FileChooser fileChooser;private Stage primaryStage;public OpenFileCommand(Stage primaryStage) {this.primaryStage = primaryStage;fileChooser = new FileChooser();fileChooser.setTitle("Open Resource File");fileChooser.getExtensionFilters().addAll(new ExtensionFilter("Text Files", "*.txt"),new ExtensionFilter("Image Files", "*.png", "*.jpg", "*.gif"),new ExtensionFilter("Audio Files", "*.wav", "*.mp3", "*.aac"));}@Overridepublic void execute() {File selectedFile = fileChooser.showOpenDialog(primaryStage);if (selectedFile != null) {System.out.println(selectedFile.getAbsolutePath());}}}public class SaveFileCommand implements Command {private Stage primaryStage;public SaveFileCommand(Stage primaryStage) {this.primaryStage = primaryStage;}@Overridepublic void execute() {FileChooser fileChooser = new FileChooser();fileChooser.setTitle("Save Resource File");fileChooser.getExtensionFilters().addAll(new ExtensionFilter("Text Files", "*.txt"),new ExtensionFilter("Image Files", "*.png", "*.jpg", "*.gif"),new ExtensionFilter("Audio Files", "*.wav", "*.mp3", "*.aac"));File selectedFile = fileChooser.showSaveDialog(primaryStage);if (selectedFile != null) {System.out.println(selectedFile.getAbsolutePath());}}}
接下来，我们创建一个带有两个按钮的UI，一个用于打开文件，另一个用于保存文件。当用户单击按钮时，将执行相应的操作。
”`java public class Main extends Application {
@Overridepublic void start(Stage primaryStage) throws Exception{Command openCommand = new OpenFileCommand(primaryStage);Command saveCommand = new SaveFileCommand(primaryStage);Button openButton = new Button("Open File");openButton.setOnAction(event -> openCommand.execute());Button saveButton = new Button("Save File");saveButton.setOnAction(event -> save
