为什么主类中的LauncherImpl.launchApplication()(javaFX launcher)正在启动InvocationTargetException而没有调用launch()? [英] Why LauncherImpl.launchApplication() (javaFX launcher) in the main class are launching InvocationTargetException and calling launch() not?

问题描述

我正在使用javaFX(13.0.2)创建一个项目，我需要使用预加载器，但是 LauncherImpl.launchApplication()失败.

I´m using javaFX (13.0.2) to make a project and I need to use a preloader, but the LauncherImpl.launchApplication() is not successful.

代码:

package classes;

import com.sun.javafx.application.LauncherImpl;
import javafx.application.Application;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) {
        System.out.println("start");
    }
    @Override
    public void init() throws Exception {
        System.out.println("init");
    }

    public static void main(String[] args) {
        LauncherImpl.launchApplication(Main.class, UIloadSystem.class, args); // - Not works
        LauncherImpl.launchApplication(Main.class, args); // - Not works
        //launch(Main.class, args); - Works
    }
}

是的，这是一个非常简单的代码

错误:

java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:363)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1051)
Caused by: java.lang.IllegalAccessError: class classes.Main (in unnamed module @0x1936f0f5) cannot access class com.sun.javafx.application.LauncherImpl (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.application to unnamed module @0x1936f0f5
    at classes.Main.main(Main.java:30)
    ... 11 more
Exception running application classes.Main

我在这部分的顶部研究了类类.Main(在未命名模块@ 0x1936f0f5中)无法访问com.sun.javafx.application.LauncherImpl类(在javafx.graphics模块中)，因为模块javafx.graphics没有将com.sun.javafx.application导出到未命名的模块@ 0x1936f0f5 ，但是
我在任何地方都找不到此活动.

I researched on top of this part class classes.Main (in unnamed module @0x1936f0f5) cannot access class com.sun.javafx.application.LauncherImpl (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.application to unnamed module @0x1936f0f5 , but
I didn't find this event anywhere.

如果很重要，我使用的是ItelliJ IDEA，VM选项为-module-path $ {PATH_TO_FX} --add-modules javafx.controls，javafx.fxml

If are imporant, I'm using ItelliJ IDEA and the VM options are --module-path ${PATH_TO_FX} --add-modules javafx.controls,javafx.fxml

对不起，如果有一些语法错误:|

Sorry for my english, if are some grammatical errors :|

推荐答案

com.sun.javafx.application.LauncherImpl 是私有API，不适合普通开发人员使用.请注意，它会启动 com.sun .所有公共JavaFX API都包含在软件包 javafx.* 中.从Java 9开始，不再可以访问私有API，但是仍然存在一些较旧的教程.

com.sun.javafx.application.LauncherImpl is private API and not intended for normal developers. Note the fact it starts com.sun. All the public JavaFX API is contained in packages javafx.*. From Java 9 onwards private API is no longer accessible, however some older tutorials still exist.

要使用预加载器，应在Java 9之后采用以下方法.

To use a preloader the following approach should be taken after Java 9.

public static void main(String[] args){
    System.setProperty("javafx.preloader", UIloadSystem.class.getCanonicalName());
    launch(args);
}

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