Graal 编译的 JavaFX 应用程序中的 java.lang.ClassNotFoundException

Question

我正在开发一个可以编译成 native 应用程序的小型 OpenJFX 项目。以下是源代码相关部分的示例:

Main.java

package app;

public class Main {

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

}

App.java

package app;

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

public class App extends Application {

    private static Scene scene;

    @Override
    public void start(Stage stage) throws Exception {
        scene = new Scene(loadFXML("MainPanel"));
        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();
    }

}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <artifactId>app</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>
    <build>
        <plugins>
            <plugin>
                <groupId>org.openjfx</groupId>
                <artifactId>javafx-maven-plugin</artifactId>
                <version>0.0.3</version>
                <configuration>
                    <mainClass>app.App</mainClass>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>3.2.0</version>
                <configuration>
                  <archive>
                    <manifest>
                      <addClasspath>true</addClasspath>
                      <mainClass>app.Main</mainClass>
                    </manifest>
                  </archive>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>3.1.0</version>
                <configuration>
                  <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                  </descriptorRefs>
                  <archive>
                    <manifest>
                      <addClasspath>true</addClasspath>
                      <mainClass>app.Main</mainClass>
                    </manifest>
                  </archive>
                </configuration>
                <executions>
                  <execution>
                    <id>make-assembly</id>
                    <phase>package</phase>
                    <goals>
                      <goal>single</goal>
                    </goals>
                  </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.graalvm.nativeimage</groupId>
                <artifactId>native-image-maven-plugin</artifactId>
                <version>19.3.0</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>native-image</goal>
                        </goals>
                        <phase>package</phase>
                    </execution>
                </executions>
                <configuration>
                    <skip>false</skip>
                    <imageName>app</imageName>
                    <buildArgs>
                        --no-fallback
                    </buildArgs>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-controls</artifactId>
            <version>13</version>
            <type>jar</type>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-fxml</artifactId>
            <version>13</version>
            <type>jar</type>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-graphics</artifactId>
            <version>13</version>
            <type>jar</type>
            <classifier>win</classifier>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-graphics</artifactId>
            <version>13</version>
            <type>jar</type>
            <classifier>linux</classifier>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-graphics</artifactId>
            <version>13</version>
            <type>jar</type>
            <classifier>mac</classifier>
        </dependency>
        <dependency>
            <groupId>org.graalvm.sdk</groupId>
            <artifactId>graal-sdk</artifactId>
            <version>19.3.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
</project>

该项目成功编译为两个 .jar 文件和一个 native 二进制文件(在本例中为 Linux x86_64 Glibc ELF 二进制文件)。非独立 .jar(稍后由 GraalVM 编译)使用 java --module-path/usr/share/openjfx/lib --add-modules javafx.controls,javafx.fxml -jar target/成功执行app-1.0-SNAPSHOT.jar。但是，生成的 native 二进制文件从终端作为 target/app 启动时会出现以下错误:

Exception in thread "main" java.lang.RuntimeException: java.lang.ClassNotFoundException: app.App
    at javafx.application.Application.launch(Application.java:304)
    at app.App.main(App.java:32)
    at app.Main.main(Main.java:6)
Caused by: java.lang.ClassNotFoundException: app.App
    at com.oracle.svm.core.hub.ClassForNameSupport.forName(ClassForNameSupport.java:60)
    at java.lang.Class.forName(DynamicHub.java:1197)
    at javafx.application.Application.launch(Application.java:292)
    ... 2 more

我做错了什么吗，GraalVM 端是否存在某种静默编译错误或缺少参数？

Answer 1

问题是 GraalVM 无​​法编译包含带反射类的独立二进制文件 unless told beforehand .这应该可以使用 native-image-maven-plugin 进行设置，但我改为切换到 Gluon Client ，这意味着我在删除不再有用的内容后对 pom.xml 添加了以下内容:

<pluginRepositories>
    <pluginRepository>
        <id>gluon-releases</id>
        <url>https://nexus.gluonhq.com/nexus/content/repositories/releases/</url>
    </pluginRepository>
</pluginRepositories>

<build>
    <plugins>
        <plugin>
            <groupId>com.gluonhq</groupId>
            <artifactId>client-maven-plugin</artifactId>
            <version>0.1.10</version>
            <configuration>
                <mainClass>app.App</mainClass>
                <reflectionList>
                    <list>javafx.fxml.FXMLLoader</list>
                    <list>app.SomeCustomClass</list>
                </reflectionList>
            </configuration>
        </plugin>
    </plugins>
</build>

请注意 app.SomeCustomClass 是返回类似 java.lang.ClassNotFoundException 错误和 javafx.fxml.FXMLLoader 的类的示例> 出于同样的原因添加。