从IntelliJ运行JavaFX应用程序

Question

版本

openjdk版本“11.0.11”2021-04-20

Exception in Application start method java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
    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:78)
    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$FXHelper.main(LauncherHelper.java:1071)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
    at java.base/java.lang.Thread.run(Thread.java:831)
Caused by: java.lang.IllegalAccessError: class com.sun.javafx.fxml.FXMLLoaderHelper (in unnamed module @0x6c5aff76) cannot access class com.sun.javafx.util.Utils (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.util to unnamed module @0x6c5aff76
    at com.sun.javafx.fxml.FXMLLoaderHelper.<clinit>(FXMLLoaderHelper.java:38)
    at javafx.fxml.FXMLLoader.<clinit>(FXMLLoader.java:2056)
    at KiloConverter.start(KiloConverter.java:12)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:846)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:455)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:428)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
    at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
    at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
    at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication.lambda$runLoop$11(GtkApplication.java:277)

如果可能的话，请不要告诉我像我以前看到其他人回答的那样“阅读基础知识”。我只是不确定为什么我的代码不能在我的最后一个项目中运行。

提前谢谢你！

Answer 1

既然您提到您是Java初学者，我首先建议您阅读以下问答：什么是堆栈跟踪，以及如何使用它来调试应用程序错误？。然后，当您回顾堆栈跟踪时，您将看到您得到的基本错误是：

Caused by: java.lang.IllegalAccessError: class com.sun.javafx.fxml.FXMLLoaderHelper (in unnamed module @0x6c5aff76) cannot access class com.sun.javafx.util.Utils (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.util to unnamed module @0x6c5aff76

这是一个与模块相关的错误。您可能希望阅读理解Java9模块以熟悉模块。

在这种情况下，出现错误是因为在类路径上找到了javafx.fxml模块，而在模块路径上找到了javafx.graphics模块。换句话说，javafx.fxml模块未能被解析为命名模块，但它的代码仍然可以在未命名模块中找到。这将破坏javafx.graphics可能给javafx.fxml的限定导出和限定打开指令，结果是IllegalAccesserRor。

// or whatever you want to name your module
module app {
  requires javafx.controls;
  requires javafx.fxml;

  // export your Application subclass's package to at least javafx.graphics
  exports com.example.app to javafx.graphics;

  // open your FXML controller package(s) to at least javafx.fxml (allows reflective access)
  opens com.example.app.controllers to javafx.fxml;
}

并将应用程序作为模块启动。例如，这就是命令行中的样子：

java --module-path <path> --module <module>/<main-class>