Apache NetBeans 20新建Ant JavaFX FXML项目持续抛出InvocationTargetException

问题背景 #

• 已配置JavaFX库、Azul Zulu（JavaJDK FX）平台，安装SceneBuilder
• 选择Java with Ant > JavaFX FXML Application创建项目，仅删除注释未修改代码
• 运行时抛出InvocationTargetException，根因是NullPointerException: Location is required
• NetBeans无语法错误，项目通常无法运行偶尔正常；清理构建时无可用类可选；清理成功后会出现“无法创建javax脚本引擎for javascript”错误

项目代码 #

Comeonwork.java #

package comeonwork;

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

public class Comeonwork extends Application {
    
    @Override
    public void start(Stage stage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));
        
        Scene scene = new Scene(root);
        
        stage.setScene(scene);
        stage.show();
    }

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

FXMLDocument.fxml #

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

<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<AnchorPane id="AnchorPane" prefHeight="200" prefWidth="320" xmlns:fx="http://javafx.com/fxml/1" fx:controller="comeonwork.FXMLDocumentController">
    <children>
        <Button layoutX="126" layoutY="90" text="Click Me!" onAction="#handleButtonAction" fx:id="button" />
        <Label layoutX="126" layoutY="120" minHeight="16" minWidth="69" fx:id="label" />
    </children>
</AnchorPane>

FXMLDocumentController.java #

package comeonwork;

import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;

public class FXMLDocumentController implements Initializable {
    
    @FXML
    private Label label;
    
    @FXML
    private void handleButtonAction(ActionEvent event) {
        System.out.println("You clicked me!");
        label.setText("Hello World!");
    }
    
    @Override
    public void initialize(URL url, ResourceBundle rb) {
        // TODO
    }    
    
}

错误日志 #

Exception in Application start method
java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:118)
    at java.base/java.lang.reflect.Method.invoke(Method.java:580)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:364)
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
    at java.base/java.lang.reflect.Method.invoke(Method.java:580)
    at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1135)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:893)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:196)
    at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: java.lang.NullPointerException: Location is required.
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3369)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3332)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3300)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3272)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3248)
    at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3241)
    at comeonwork.Comeonwork.start(Comeonwork.java:21)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:839)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:483)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:456)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:455)
    at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    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:185)
    ... 1 more
Exception running application comeonwork.Comeonwork
C:\Users\Aun\Documents\NetBeansProjects\comeonwork\nbproject\build-impl.xml:1367: The following error occurred while executing this line:
C:\Users\Aun\Documents\NetBeansProjects\comeonwork\nbproject\build-impl.xml:962: Java returned: 1
BUILD FAILED (total time: 1 second)

解决步骤 #

1. 修复FXML文件加载路径 #

NullPointerException: Location is required核心原因是FXML文件未被正确加载：

• 确认FXMLDocument.fxml和Comeonwork.java在同一包目录（src/comeonwork/）下
• 修改加载代码为绝对路径（斜杠开头表示从类根目录开始）：

  Parent root = FXMLLoader.load(getClass().getResource("/comeonwork/FXMLDocument.fxml"));
  

• 配置Ant构建，确保FXML文件被复制到编译目录：
  打开项目build.xml，添加以下任务：

  <target name="-post-compile">
      <copy todir="${build.classes.dir}">
          <fileset dir="${src.dir}" includes="**/*.fxml"/>
      </copy>
  </target>
  

2. 解决清理构建类列表为空问题 #

• 进入项目属性 > 构建 > 编译，确认源包路径指向src/目录
• 手动删除项目根目录下的build文件夹，重新执行构建
• 检查Java平台配置：工具 > Java平台，确保Azul Zulu平台的源和Javadoc路径正确关联

3. 处理脚本引擎错误 #

• 使用完整版本的Azul Zulu JDK FX，避免精简版
• 在项目运行配置中添加VM参数：

  --add-modules jdk.scripting.nashorn
  

  注意：Java 15及以上版本已移除Nashorn，若使用高版本JDK，需更换JS引擎或降级到Java 11/14

内容的提问来源于stack exchange，提问作者Aun