VSCode重启后JavaFX项目无法运行，报错Location is required

云原生阿岚

2026-7-3

问题描述

昨日创建的JavaFX项目运行完全正常，但今日重启VSCode或电脑后再次运行时出现报错，另一项目也出现相同问题。已正确添加JavaFX库及配置，相关代码、启动配置及错误日志如下：

第一个类（FxmlDocumentController.java）

import java.net.URL;
import java.util.ResourceBundle;

import javafx.animation.TranslateTransition;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Hyperlink;
import javafx.scene.control.PasswordField;
import javafx.scene.control.TextField;
import javafx.scene.layout.AnchorPane;
import javafx.util.Duration;

public class FxmlDocumentController implements Initializable {

    @FXML
    private Hyperlink si_forgotPass;

    @FXML
    private Button si_loginBtn;

    @FXML
    private AnchorPane si_loginForm;

    @FXML
    private PasswordField si_password;

    @FXML
    private TextField si_username;

    @FXML
    private Button side_createBtn;

    @FXML
    private AnchorPane side_form;

    @FXML
    private TextField su_answer;

    @FXML
    private PasswordField su_password;

    @FXML
    private ComboBox<?> su_question;

    @FXML
    private Button su_signUpBtn;

    @FXML
    private AnchorPane su_signUpForm;

    @FXML
    private TextField su_username;

    @FXML
    private Button side_alreadyHave;

    public void switchForm(ActionEvent event) {

        TranslateTransition slider = new TranslateTransition();

        if (event.getSource() == side_createBtn) {
            slider.setNode(side_form);
            slider.setToX(300);
            slider.setDuration(Duration.seconds(.5));
            slider.setOnFinished((ActionEvent e) -> {
                side_alreadyHave.setVisible(true);
                side_createBtn.setVisible(false);
            });

            slider.play();

        } else if (event.getSource() == side_alreadyHave) {
            slider.setNode(side_form);
            slider.setToX(0);
            slider.setDuration(Duration.seconds(.5));
            slider.setOnFinished((ActionEvent e) -> {
                side_alreadyHave.setVisible(false);
                side_createBtn.setVisible(true);
            });

            slider.play();
        }
    }

    @Override
    public void initialize(URL arg0, ResourceBundle arg1) {
       
    }

}

第二个类（CafeShopManagmentSystem.java）

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

public class CafeShopManagmentSystem extends Application {

    @Override
    public void start(Stage stage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("C:\\Users\\nsoor\\OneDrive\\Desktop\\CafeProject\\CafeShopManagementSystem\\src\\FxmlDocumentController.java"));

        Scene scene = new Scene(root);

        stage.setScene(scene);
        stage.show();
    }

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

启动配置（launch.json）

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [

        {
            "type": "java",
            "name": "Current File",
            "request": "launch",
            "mainClass": "${file}"
        },
        {
            "type": "java",
            "name": "CafeShopManagmentSystem",
            "request": "launch",
            "mainClass": "CafeShopManagmentSystem",
            "projectName": "CafeShopManagementSystem_b45da6ad",
            "vmArgs": "--module-path \"C:/java/lib\" --add-modules javafx.controls,javafx.fxml"
        },
        {

            "type": "java",
            "name": "FxmlDocumentController",
            "request": "launch",
            "mainClass": "FxmlDocumentController",
            "projectName": "CafeShopManagementSystem_b45da6ad",
            "vmArgs": "--module-path \"C:/java/lib\" --add-modules javafx.controls,javafx.fxml"
        }
    ]
}

错误日志

PS C:\Users\nsoor\OneDrive\سطح المكتب\CafeProject\CafeShopManagementSystem>  & 'C:\Users\nsoor\scoop\apps\oraclejdk\18.0.2.1\bin\java.exe' '@C:\Users\nsoor\AppData\Local\Temp\cp_6r3pd7ec9uu67bxxyvokb3rac.argfile' 'CafeShopManagmentSystem' 
Exception in Application start method
java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:119)
        at java.base/java.lang.reflect.Method.invoke(Method.java:577)
        at javafx.graphics@21.0.1/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
        at javafx.graphics@21.0.1/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:364)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
        at java.base/java.lang.reflect.Method.invoke(Method.java:577)
        at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1081)
Caused by: java.lang.RuntimeException: Exception in Application start method
        at javafx.graphics@21.0.1/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:893)
        at javafx.graphics@21.0.1/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:196)
        at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.NullPointerException: Location is required.
        at javafx.fxml@21.0.1/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3369)
        at javafx.fxml@21.0.1/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3332)
        at javafx.fxml@21.0.1/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3300)
        at javafx.fxml@21.0.1/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3272)
        at javafx.fxml@21.0.1/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3248)
        at javafx.fxml@21.0.1/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3241)
        at CafeShopManagmentSystem.start(CafeShopManagmentSystem.java:11)
        at javafx.graphics@21.0.1/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:839)
        at javafx.graphics@21.0.1/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:483)
        at javafx.graphics@21.0.1/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:456)
        at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
        at javafx.graphics@21.0.1/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:455)
        at javafx.graphics@21.0.1/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
        at javafx.graphics@21.0.1/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
        at javafx.graphics@21.0.1/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:185)
        ... 1 more
Exception running application CafeShopManagmentSystem

解决方案

报错核心是NullPointerException: Location is required，问题出在CafeShopManagmentSystem类的start方法里：

加载目标错误：你用FXMLLoader加载的是Java控制器文件（FxmlDocumentController.java），但FXMLLoader需要加载的是FXML布局文件（通常为.fxml后缀），这是根本错误。
绝对路径问题：使用绝对路径加载资源会导致环境变化（比如重启、路径权限变更）时无法找到文件，应该改用类路径下的相对路径。

修改步骤：

确保FXML布局文件（比如FxmlDocument.fxml）和控制器类在同一目录下，或已正确配置类路径。
修改start方法中的加载代码，示例如下：

@Override
public void start(Stage stage) throws Exception{
    // 假设FXML文件名为FxmlDocument.fxml，和当前类在同一包下
    Parent root = FXMLLoader.load(getClass().getResource("FxmlDocument.fxml"));

    Scene scene = new Scene(root);

    stage.setScene(scene);
    stage.show();
}

另外，启动配置里的FxmlDocumentController配置项可以删除，因为控制器类不是JavaFX应用的入口类，无法直接启动。

内容的提问来源于stack exchange，提问作者NAZ

VSCode重启后JavaFX项目无法运行，报错Location is required

第一个类（FxmlDocumentController.java） #

第二个类（CafeShopManagmentSystem.java） #

启动配置（launch.json） #

错误日志 #

第一个类（FxmlDocumentController.java）

第二个类（CafeShopManagmentSystem.java）

启动配置（launch.json）

错误日志