JavaFX、场景生成器 (IntelliJ) 程序从 StackOverFlow 抛出 java.lang.reflect.InitationTargetException

Question

在我的代码中，我尝试为我的战舰项目设置主菜单，在将场景生成器中的播放按钮分配给 MainMenu 类中的 usePlayButton 方法后，程序停止工作。这是我第一次尝试将程序链接在一起，之前我只显示了主菜单屏幕。

偶尔，我会收到错误“java.lang.instrument ASSERTION FAILED ***: "!errorOutstanding"with message conversion method call failed at JPLISAgent.c line: 844” 但是，此错误似乎是随机发生的，没有任何已知的原因。运行调试器，在我的 MainController 类中创建 mainMenu 时，程序似乎崩溃了。我缩短了错误报告以减少帖子中使用的字符数。

错误:

Exception in Application start method
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
    at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$1(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.StackOverflowError
    at java.util.HashMap.hash(HashMap.java:339)
    at java.util.HashMap.get(HashMap.java:557)
    at sun.misc.JarIndex.get(JarIndex.java:175)

我已经尝试了一些从本网站的相关问题中看到的修复方法。我已将 src/res 文件夹设置为 IntelliJ 将其视为资源文件夹。我尝试创建 MainMenu 类中使用的按钮。我已经给我的 AnchorPane 一个 root 的 fx:id 。一路上还有其他事情。

我的文件结构是:

主 Controller

    package controllers;

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

import static javafx.fxml.FXMLLoader.load;

/**
 * The Main class handles the setup of the game and loads the JavaFX features of the program.
 * Main has the user choose the size of the board.
 * Main handles the main menu
 *
 * @author Devon X. Dalrymple
 * @version 2019.11.13-03
 */
public class MainController extends Application {


    private static Stage game;
    public MainMenu mainMenu;
    public ChooseSize chooseSize;



    /**
     * @param primaryStage stage used to run JavaFX program
     * @throws Exception thrown when the stage is not loaded correctly
     */
    @Override
    public void start(Stage primaryStage) throws Exception {

        game = primaryStage;


        mainMenu = new MainMenu();
        chooseSize = new ChooseSize();
        game.setTitle("Devon's Battleship");
        game.setScene(mainMenu.getScene());
        game.show();
    }

    /**
     * main method that launches javaFX and loads the program
     * @param args
     */
    public static void main(String[] args) {
        launch(args);
    }

    /**
     * Sets the primaryStage scene to the scene provided by the parameter
     * @param scene, Scene to change to
     */
    public void setScene(Scene scene)
    {
        game.setScene(scene);
    }
}

主菜单类:

package controllers;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.AnchorPane;


import java.io.IOException;

/**
 * Handles the Main Menu and its buttons
 *
 * @author Devon X. Dalrymple
 * @version 2019.11.14-02
 */
public class MainMenu {

    private Parent menu;
    Scene scene;
    ActionEvent eventPlay;
    MainController mainController;
    @FXML Button playGame;
    @FXML AnchorPane root;
    @FXML Label menuLabel;
    @FXML Button rulesButton;
    @FXML Button quitButton;

    /**
     * Sets up the main menu and loads the related fxml file
     * @throws IOException
     */
    public MainMenu() throws IOException {
        playGame = new Button();
        root = new AnchorPane();
        menuLabel = new Label();
        rulesButton = new Button();
        quitButton = new Button();
        mainController = new MainController();
        menu = FXMLLoader.load(getClass().getResource("../res/MainMenu.fxml"));
        scene = new Scene(menu);
        eventPlay = new ActionEvent();
    }

    /**
     * Returns the main menu to load as the current scene
     * @return menu Main Menu of the game
     */
    public Scene getScene()
    {
        return scene;
    }

    /**
     * Connected using Scene Builder to change the scene whenever the play game button is clicked
     * @param eventPlay
     */
    public void usePlayGame(ActionEvent eventPlay)
    {
        mainController.setScene(mainController.chooseSize.getScene());
    }
}

MainMenu fxml

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Font?>

<AnchorPane id="AnchorPane" fx:id="root" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="720.0" prefWidth="1280.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controllers.MainMenu">
  <children>
    <Label id="chooseSize" fx:id="menuLabel" layoutX="503.0" layoutY="101.0" text="Devon's Battleship" textAlignment="CENTER">
      <font>
        <Font name="System Bold" size="26.0" />
      </font>
    </Label>
    <Button id="makeTiny" fx:id="playGame" layoutX="558.0" layoutY="256.0" mnemonicParsing="false" onAction="#usePlayGame" prefWidth="166.0" text="Play Game">
      <font>
        <Font size="18.0" />
      </font>
    </Button>
    <Button id="makeTiny" fx:id="rulesButton" layoutX="558.0" layoutY="312.0" mnemonicParsing="false" prefWidth="166.0" text="How to Play">
         <font>
            <Font size="18.0" />
         </font></Button>
    <Button id="makeTiny" fx:id="quitButton" layoutX="558.0" layoutY="366.0" mnemonicParsing="false" prefWidth="166.0" text="Quit Game">
         <font>
            <Font size="18.0" />
         </font></Button>
  </children>
</AnchorPane>

选择尺寸类别

package controllers;

import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;

import java.io.IOException;

/**
 * Handles the Main Menu and its buttons
 *
 * @author Devon X. Dalrymple
 * @version 2019.11.14-02
 */
public class ChooseSize {



    private Parent menu;
    Scene scene;

    /**
     * Creates the choose size scene to select board size by loading the appropriate fxml file
     * @throws IOException
     */
    public ChooseSize() throws IOException {
        menu = FXMLLoader.load(getClass().getResource("../res/ChooseSize.fxml"));
        scene = new Scene(menu);
    }

    /**
     * Returns the main menu to load as the current scene
     * @return menu Main Menu of the game
     */
    public Scene getScene() {
            return scene;
    }
}

我正在使用这个项目来教我 JavaFX，我不确定我是否犯了一些容易修复的错误，任何帮助将不胜感激。

Answer 1

public MainMenu() throws IOException { ... menu = FXMLLoader.load(getClass().getResource("../res/MainMenu.fxml")); ...} <... fx:controller="controllers.MainMenu">... This alone should result in an stackoverflow even before you get the main menu loaded... – fabian

在看到 fabian 的评论并查看其他人如何编码 JavaFX 程序后，我删除了 fxml 文件中对 MainMenu 的引用，并将我的程序设置方式更改为:

主 Controller

/**
 * @param primaryStage stage used to run JavaFX program
 * @throws Exception thrown when the stage is not loaded correctly
 */
@Override
public void start(Stage primaryStage) throws Exception {

    game = primaryStage;

    MainMenu mainMenu = new MainMenu();
    ChooseSize chooseSize = new ChooseSize();

    theMainMenu = new Scene(mainMenu.getContent());
    chooseSizeMenu = new Scene(chooseSize.getContent());



    game.setTitle("Devon's Battleship");
    game.setScene(theMainMenu);
    game.show();
}

/**
 * main method that launches javaFX and loads the program
 * @param args
 */
public static void main(String[] args) throws IOException {

    launch(args);
}

/**
 * Sets the primaryStage scene to the scene provided by the parameter
 * @param sceneID, Scene to change to using its corresponding ID number
 */
public static void setScene(int sceneID)
{
    if (sceneID == 0)
    {
        game.setScene(theMainMenu);
    }
    if (sceneID == 1)
    {
        game.setScene(chooseSizeMenu);
    }

}

主菜单

/**
     * Sets up the main menu and loads the related fxml file
     * @throws IOException
     */
    public MainMenu() throws IOException {

        base = FXMLLoader.load(getClass().getResource("../res/MainMenuGUI.fxml"));

    }

    /**
     * Returns the main menu to load as the current scene
     * @return menu Main Menu of the game
     */
    public Parent getContent()
    {
        return base;
    }

    /**
     * Connected using Scene Builder to change the scene whenever the play game button is clicked
     * @param eventPlay
     */
    public void usePlayGame(ActionEvent eventPlay)
    {
        MainController.setScene(1);  //sceneID of chooseSizeMenu
    }