试图从Java调用JavaFX应用程序… NoSuchMethodException

我有一个主类，它应该调用JavaFX应用程序（SimpleSun）来从用户获取信息。 目前我创建了一个JavaFX类的Object并启动它，但这似乎不起作用。 有人看到我工作中的错误吗？

这是我的代码和exception：Main.java：

package ch.i4ds.stix.sim; import ch.i4ds.stix.sim.grid.config.Configuration; import ch.i4ds.stix.sim.grid.config.ConfigurationFromFile; public class Main{ Configuration config; public static void main(String[] args) { ConfigurationFromFile config = new ConfigurationFromFile(); SimpleSun ss = new SimpleSun(config); ss.show(); } } 

SimpleSun.java：

 import javafx.application.Application; import javafx.fxml.FXMLLoader; import javafx.scene.Scene; import javafx.scene.layout.BorderPane; import javafx.stage.Stage; import ch.i4ds.stix.sim.grid.config.Configuration; import ch.i4ds.stix.sim.grid.config.ConfigurationFromFile; public class SimpleSun extends Application{ private Stage primaryStage; Configuration configuration; public SimpleSun(ConfigurationFromFile config) { this.configuration = config; } @Override public void start(Stage primaryStage) throws Exception { this.primaryStage = primaryStage; this.primaryStage.setTitle("Simple Sun - Alpha"); System.out.println("Test"); try { // Load the root layout from the fxml file FXMLLoader loader = new FXMLLoader( Main.class.getResource("view/RootLayout.fxml")); BorderPane rootLayout = (BorderPane) loader.load(); Scene scene = new Scene(rootLayout); primaryStage.setScene(scene); primaryStage.show(); } catch (IOException e) { // Exception gets thrown if the fxml file could not be loaded e.printStackTrace(); } } public void show(){ launch(); } } 

例外：

 Exception in Application constructor Exception in thread "main" java.lang.RuntimeException: Unable to construct Application instance: class ch.i4ds.stix.sim.SimpleSun at com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source) at com.sun.javafx.application.LauncherImpl.access$000(Unknown Source) at com.sun.javafx.application.LauncherImpl$1.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: java.lang.NoSuchMethodException: ch.i4ds.stix.sim.SimpleSun.() at java.lang.Class.getConstructor0(Unknown Source) at java.lang.Class.getConstructor(Unknown Source) ... 4 more 

Answer 1

扩展应用程序时，必须提供不带参数的构造函数。 所以你可以这样做：

 public class SimpleSun extends Application { private Stage primaryStage; Configuration configuration; public SimpleSun() { this.configuration = Main.getConfig(); } //... 

并在您的Main类：

 public static Configuration getConfig() { return new ConfigurationFromFile(); } 

或者，您可以使用launch(args)将String参数传递给类，并使用getParameters()将它们返回到SimpleSun类中。