java.lang.reflect.InvocationTargetException错误javafx即使没有代码[重复]

Question

我是 javafx 的新手，所以我决定做一个项目， 但是当我运行程序时（在 start 方法中实际上没有代码） 它不起作用，它说 java.lang.reflect.InvocationTargetException 错误，还有一个

这里是代码

package com.front.fire;

import javafx.application.Application;
import javafx.stage.Stage;

class FrontFireMain extends Application{

    @Override
    public void start(Stage arg0) throws Exception {
        
    }

}

Exception in thread "main" 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 java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1071)        
Caused by: java.lang.RuntimeException: Unable to construct Application instance: class com.front.fire.FrontFireMain
        at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:890)
        at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
        at java.base/java.lang.Thread.run(Thread.java:831)
Caused by: java.lang.NoSuchMethodException: com.front.fire.FrontFireMain.<init>()
        at java.base/java.lang.Class.getConstructor0(Class.java:3517)
        at java.base/java.lang.Class.getConstructor(Class.java:2238)
        at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:801)
        at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:474)
        at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:447)
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)     
        at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:446)
        at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
        at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
        at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
        ... 1 more

Answer 1

您的主类扩展 javafx.application.Application 需要公开。如下更改您的课程。

package com.front.fire;

import javafx.application.Application;
import javafx.stage.Stage;

public class FrontFireMain extends Application{

    @Override
    public void start(Stage arg0) throws Exception {
        
    }

}