试图从Java调用JavaFX应用程序... NoSuchMethodException [英] Trying to call a JavaFX application from Java... NoSuchMethodException

问题描述

我有一个主类，它应该调用JavaFX应用程序（SimpleSun）来从用户那里获取信息。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？

I have a main class which should call a JavaFX application (SimpleSun) to get Information from the user. Currently I create an Object of the JavaFX class and start it, but that doesn't seem to work. Does someone see the mistake in my work?

这是我的代码和例外：
Main.java：

Here's my code and 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：

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();
    }

}

异常：

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.<init>()
    at java.lang.Class.getConstructor0(Unknown Source)
    at java.lang.Class.getConstructor(Unknown Source)
    ... 4 more

推荐答案

你必须提供一个没有参数的构造函数当你扩展应用程序时。所以你可以这样做：

You must provide a constructor with no arguments when you extend application. So you could do something like:

public class SimpleSun extends Application {

    private Stage primaryStage;
    Configuration configuration;

    public SimpleSun() {
        this.configuration = Main.getConfig();
    }
    //...

以及 Main class：

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

或者你可以将 String 参数传递给使用 launch（args）的类，并使用 getParameters将它们返回到 SimpleSun 类中）。

Alternatively you can pass String parameters to the class with launch(args) and get them back in the SimpleSun class with getParameters().

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