如何修复InvocationTargetException javaFX Maven库

我是javafx的新手，目前正在使用javafx与Maven lib进行一个项目。尽管在添加锚窗格和带有一些ID的按钮后，我遇到了以下错误：

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: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$FXHelper.main(LauncherHelper.java:1051)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
    at java.base/java.lang.Thread.run(Thread.java:830)
Caused by: javafx.fxml.LoadException: No controller specified.
/Users/kevintruong/maven-project/InventoryTracker/target/classes/com/flexus/InventoryTracker/primary.fxml:9

    at javafx.fxml/javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2621)
    at javafx.fxml/javafx.fxml.FXMLLoader.access$100(FXMLLoader.java:105)
    at javafx.fxml/javafx.fxml.FXMLLoader$Element.getControllerMethodHandle(FXMLLoader.java:565)
    at javafx.fxml/javafx.fxml.FXMLLoader$Element.processEventHandlerAttributes(FXMLLoader.java:607)
    at javafx.fxml/javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:778)
    at javafx.fxml/javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2838)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2557)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2466)
    at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:2435)
    at com.flexus.InventoryTracker/com.flexus.InventoryTracker.App.loadFXML(App.java:31)
    at com.flexus.InventoryTracker/com.flexus.InventoryTracker.App.start(App.java:20)
    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)
Exception running application com.flexus.InventoryTracker.App
[ERROR] Command execution failed.
org.apache.commons.exec.ExecuteException: Process exited with an error: 1 (Exit value: 1)
    at org.apache.commons.exec.DefaultExecutor.executeInternal(DefaultExecutor.java:404)
    at org.apache.commons.exec.DefaultExecutor.execute(DefaultExecutor.java:166)
    at org.openjfx.JavaFXRunMojo.executeCommandLine(JavaFXRunMojo.java:525)
    at org.openjfx.JavaFXRunMojo.executeCommandLine(JavaFXRunMojo.java:487)
    at org.openjfx.JavaFXRunMojo.execute(JavaFXRunMojo.java:168)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:956)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:192)
    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 org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:347)
org.apache.commons.exec.ExecuteException: Process exited with an error: 1 (Exit value: 1)
    at org.apache.commons.exec.DefaultExecutor.executeInternal(DefaultExecutor.java:404)
    at org.apache.commons.exec.DefaultExecutor.execute(DefaultExecutor.java:166)
    at org.openjfx.JavaFXRunMojo.executeCommandLine(JavaFXRunMojo.java:525)
    at org.openjfx.JavaFXRunMojo.executeCommandLine(JavaFXRunMojo.java:487)
    at org.openjfx.JavaFXRunMojo.execute(JavaFXRunMojo.java:168)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:956)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:192)
    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 org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:347)

我的主控制器：

package com.flexus.InventoryTracker;

import java.io.IOException;

import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.Label;

public class PrimaryController {

    @FXML
    private Button signUp;

    @FXML
    void switchToSignUp() throws IOException {
        App.setRoot("primary");
    }

}

我的主要班级：

package com.flexus.InventoryTracker;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

import java.io.IOException;

/**
 * JavaFX App
 */
public class App extends Application {

    private static Scene scene;

    @Override
    public void start(Stage stage) throws IOException {
        scene = new Scene(loadFXML("primary"));
        stage.setScene(scene);
        stage.show();
    }

    static void setRoot(String fxml) throws IOException {
        scene.setRoot(loadFXML(fxml));
    }

    private static Parent loadFXML(String fxml) throws IOException {
        FXMLLoader fxmlLoader = new FXMLLoader(App.class.getResource(fxml + ".fxml"));
        return fxmlLoader.load();
    }

    public static void main(String[] args) {
        launch();
    }

}

我的主要fxml：

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.AnchorPane?>


<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" style="-fx-background-color: #FDFEFE;" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1">
   <children>
      <Button fx:id="signUp" layoutX="529.0" layoutY="14.0" mnemonicParsing="false" onAction="#switchToSignUp" style="-fx-background-color: #FDFEFE;" text="Sign up" textFill="#3498db" underline="true" />
   </children>
</AnchorPane>

---

经过数小时的研究，我仍然没有找到任何解决这个错误的方法。有人知道我做错了什么吗？

调用targetException从来不是问题的根源。当通过反射调用一个方法但该方法本身抛出异常时，就会抛出该异常。通过反射调用方法引发的异常由

InvocationTargetException

包装（即原因）。Q&A提供了有关堆栈跟踪以及如何读取它们的更多信息

因此，如果我们查看堆栈跟踪中由引起的最后一个

，我们会发现基本错误是：

原因：javafx.fxml.LoadException:未指定控制器。
/Users/kevintroung/maven project/InventoryTracker/target/classes/com/flexus/InventoryTracker/primary.fxml:9

注意：以“
[ERROR]命令执行失败”开头的输出来自Maven，而不是您的应用程序

现在，并不总是需要指定控制器类；但是，在FXML文件中：


，包名称应全部为小写

如果使用的是场景生成器，则可以通过转到左侧面板中的“文档”部分，展开“控制器”窗格，并在标记为“控制器类”的文本字段中键入控制器类的名称来指定控制器

有关FXML的更多信息，请参阅。
调用TargetException
从来不是问题的根源。当通过反射调用一个方法但该方法本身抛出异常时，就会抛出该异常。通过反射调用方法引发的异常由
InvocationTargetException
包装（即原因）。Q&A提供了有关堆栈跟踪以及如何读取它们的更多信息

因此，如果我们查看堆栈跟踪中由
引起的最后一个
，我们会发现基本错误是：

原因：javafx.fxml.LoadException:未指定控制器。
/Users/kevintroung/maven project/InventoryTracker/target/classes/com/flexus/InventoryTracker/primary.fxml:9

注意：以“
[ERROR]命令执行失败”开头的输出来自Maven，而不是您的应用程序

现在，并不总是需要指定控制器类；但是，在FXML文件中：


，包名称应全部为小写

如果使用的是场景生成器，则可以通过转到左侧面板中的“文档”部分，展开“控制器”窗格，并在标记为“控制器类”的文本字段中键入控制器类的名称来指定控制器

有关FXML的更多信息，请参阅。
Hi Slaw，非常感谢您的详细解释，它工作得非常好！嗨，Slaw，非常感谢您的详细解释，它工作得非常好！