Question

我使用JavaFX制作了一个应用程序，当我使用IntelliJ IDE上的“构建”按钮构建项目时，它可以正常工作。但是，当我从gradle JavaFX项目生成的jar文件中运行时，它不起作用，并且控制台上显示以下错误。

$java -jar sample-menu-all.jar

java.io.FileNotFoundException: file:/Users/myuser/MyProjectRoot/build/libs/sample-menu-all.jar!/images/main_menu/icon.svg (No such file or directory)
    at java.base/java.io.FileInputStream.open0(Native Method)
    at java.base/java.io.FileInputStream.open(FileInputStream.java:220)
    at java.base/java.io.FileInputStream.<init>(FileInputStream.java:158)
    at java.base/java.io.FileInputStream.<init>(FileInputStream.java:113)
    at java.base/java.io.FileReader.<init>(FileReader.java:58)
    at presentation.utils.ImageUtil.loadSvgImage(ImageUtil.java:23)
    at presentation.controller.MenuController.loadRegistrationButtonImage(MenuController.java:25)
    at presentation.controller.MenuController.initialize(MenuController.java:20)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2573)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2466)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3253)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3210)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3179)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3152)
    at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3144)
    at presentation.navigator.VitalBitMenuNavigator.launchNewScene(VitalBitMenuNavigator.java:22)
    at presentation.navigator.VitalBitMenuNavigator.launchMenuStage(VitalBitMenuNavigator.java:33)
    at presentation.MainApp.start(MainApp.java:20)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:919)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$11(PlatformImpl.java:449)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$9(PlatformImpl.java:418)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:417)
    at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
javafx.fxml.LoadException:
file:/Users/myuser/MyProjectRoot/build/libs/sample-menu-all.jar!/fxml/menu.fxml

    at javafx.fxml/javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2625)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2603)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2466)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3253)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3210)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3179)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3152)
    at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3144)
    at presentation.navigator.VitalBitMenuNavigator.launchNewScene(VitalBitMenuNavigator.java:22)
    at presentation.navigator.VitalBitMenuNavigator.launchMenuStage(VitalBitMenuNavigator.java:33)
    at presentation.MainApp.start(MainApp.java:20)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:919)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$11(PlatformImpl.java:449)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$9(PlatformImpl.java:418)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:417)
    at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
Caused by: java.lang.NullPointerException
    at javafx.swing/javafx.embed.swing.SwingFXUtils.toFXImage(SwingFXUtils.java:77)
    at presentation.utils.ImageUtil.loadSvgImage(ImageUtil.java:30)
    at presentation.controller.MenuController.loadRegistrationButtonImage(MenuController.java:25)
    at presentation.controller.MenuController.initialize(MenuController.java:30)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2573)
    ... 15 more

我的目录结构是这个

ProjectRootDir
|-- build
  |-- libs
    sample-menu-all.jar
|-- build.gradle
|-- src
  |-- main
    |-- java
      |-- presentation
        MainApp.java
        |-- controller
          |-- MenuController.java
        |-- navigator 
          |-- MenuNavigator.java
        |-- utils
          |-- ImageUtile.java
    |-- resources
      |-- fxml
        |-- menu.fxml
      |-- properties
        |-- string.properties

gradle文件main.java和fxml类已加载在snnipet链接中。

build.gradle

    buildscript {
    dependencies {
        classpath group: 'de.dynamicfiles.projects.gradle.plugins', name: 'javafx-gradle-plugin', version: '8.8.2'
        classpath 'com.github.jengelman.gradle.plugins:shadow:2.0.4'
    }
    repositories {
        jcenter()
        mavenLocal()
        mavenCentral()
    }
}

plugins {
    id 'java'
}

version '1.0-SNAPSHOT'
apply plugin: 'java'
apply plugin: 'application'
apply plugin: 'com.github.johnrengelman.shadow'
apply plugin: 'javafx-gradle-plugin'

mainClassName = 'presentation.MainApp'
sourceCompatibility = 1.8

repositories {
    mavenLocal()
    mavenCentral()
}

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.12'
    // Camera lib
    compile 'com.github.sarxos:webcam-capture:0.3.12'
    compile 'org.slf4j:slf4j-log4j12:1.7.21'
    // RxJavaFX
    implementation "io.reactivex.rxjava2:rxjava:2.2.2"
    // Retrofit
    implementation 'com.squareup.retrofit2:retrofit:2.4.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.4.0'
    implementation 'com.squareup.retrofit2:adapter-rxjava2:2.4.0'
    // Batik (for loading AVG)
    compile group: 'org.apache.xmlgraphics', name: 'batik-transcoder', version: '1.10'
}


jfx {
    mainClass = 'MainApp'
    vendor = 'myVendor'
}

jar {
    manifest {
        attributes 'Main-Class': 'presentation.MainApp'
    }
    from {
        configurations.compile.collect {
            it.isDirectory() ? it : zipTree(it)
        }
    }
}

sourceSets {
    main {
        java {
            srcDirs 'src/main/java'
        }
        resources {
            srcDirs 'src/main/resources'
        }
    }
}

MainApp.java

package presentation;

import javafx.application.Application;
import javafx.stage.Stage;
import presentation.navigator.MenuNavigator;

public class MainApp extends Application {

    public static Stage primaryStage;

    private MenuNavigator navigator;

    public MainApp() {
        navigator = new MenuNavigator();
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        MainApp.primaryStage = primaryStage;
        navigator.launchMenuStage(primaryStage);
    }

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

MenuNavigator.java

    import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import presentation.utils.ResourceBundleUtf8Control;
import presentation.utils.config.Config;
import java.io.File;
import java.net.URL;
import java.io.IOException;
import java.util.Locale;
import java.util.ResourceBundle;

public class MenuNavigator {

    private void launchNewScene(Stage stage, String $fxmlName) {
        try {
            URL location = getClass().getResource("/fxml/" + $fxmlName);
            ResourceBundle resources = ResourceBundle.getBundle("properties.string", Locale.getDefault(), new ResourceBundleUtf8Control());
            Parent root = FXMLLoader.load(location, resources);
            Scene scene = new Scene(root, Config.loadDimen("dimension.app_screen_size.width"), Config.loadDimen("dimension.app_screen_size.height"));
            stage.setScene(scene);
            stage.setTitle(Config.loadString("string.title"));
            stage.show();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void launchMenuStage(Stage stage) {
        launchNewScene(stage, "menu.fxml");
    }
}

MenuContoroller.java

package presentation.controller;

import javafx.event.ActionEvent;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.image.ImageView;
import presentation.MainApp;
import presentation.utils.FileUtil;
import presentation.utils.ImageUtil;
import java.net.URL;
import java.util.ResourceBundle;

public class MenuController extends BaseController implements Initializable {

    public Button userRegistrationButton;

    @Override
    public void initialize(URL arg0, ResourceBundle arg1) {
        this.loadRegistrationButtonImage();
    }

    private void loadRegistrationButtonImage() {
        ImageView buttonImage = new ImageView();
        ImageUtil.loadSvgImage(buttonImage, "/images/main_menu/icon.svg", 71, 94);
        userRegistrationButton.setGraphic(buttonImage);
        userRegistrationButton.setGraphicTextGap(37.5);
    }

}

ImageUtile.java

package presentation.utils;

import javafx.embed.swing.SwingFXUtils;
import javafx.scene.image.ImageView;
import javafx.scene.image.WritableImage;
import org.apache.batik.transcoder.TranscoderException;
import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.image.PNGTranscoder;
import java.awt.image.BufferedImage;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.net.URL;

public class ImageUtil {
    public static void loadSvgImage(ImageView target, String resourcePath, int withd, int height) {
        SvgTranscoder imageTranscoder = new SvgTranscoder();

        imageTranscoder.addTranscodingHint(PNGTranscoder.KEY_WIDTH, (float) withd);
        imageTranscoder.addTranscodingHint(PNGTranscoder.KEY_HEIGHT, (float) height);

        try {
            URL imagePath = ImageUtil.class.getResource(resourcePath);
            TranscoderInput input = new TranscoderInput(new FileReader(imagePath.getFile()));
            imageTranscoder.transcode(input, null);
        } catch (FileNotFoundException | TranscoderException e) {
            e.printStackTrace();
        }

        BufferedImage bimage =  imageTranscoder.getImage();
        WritableImage wimage = SwingFXUtils.toFXImage(bimage, null);
        target.setImage(wimage);
    }
}

SvgTranscoder.java

package presentation.utils;

import org.apache.batik.transcoder.TranscoderOutput;
import org.apache.batik.transcoder.image.ImageTranscoder;

import java.awt.image.BufferedImage;

public class SvgTranscoder extends ImageTranscoder {

    private BufferedImage image = null;

    @Override
    public BufferedImage createImage(int w, int h) {
        image = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
        return image;
    }

    @Override
    public void writeImage(BufferedImage img, TranscoderOutput out) {
    }

    public BufferedImage getImage() {
        return image;
    }
}

这里也有相同的代码段。 https://snippets.cacher.io/snippet/3dab5b901e6aa5e861e3

我解压缩了jar文件并检查了fxml目录，并包含了文件。这是屏幕截图。 Unpacked jar files

如果有人对此问题提出建议，我将不胜感激。

Answer 1

问题是这样的：

new FileReader(imagePath.getFile())

URL名称的getFile（）方法尽管命名，但不会返回有效的文件名，并且不会将URL转换为文件。（该方法是20年前在Java 1.0中引入的，当时大多数URL实际上都表示同一台计算机上或另一台计算机上的物理文件。）

即使存在，.jar文件也只是一个存档，其中的条目本身并不是文件本身，只是代表压缩数据的字节的子序列。

您必须将.jar条目中的资源称为资源URL或其等效流。您不得尝试将其转换为文件。

幸运的是，您不需要文件。您可以将URL作为字符串直接传递：

URL imagePath = ImageUtil.class.getResource(resourcePath);
TranscoderInput input = new TranscoderInput(imagePath.toString());

图像未从JavaFX项目中gradle构建的jar中加载