编译javaFX项目时"class file有错误的版本54.0，应该是52.0"

Question

我曾尝试用maven构建一个示例javaFX项目，我不断地得到下面的错误。

Error:(3, 26) java: cannot access javafx.application.Application
  bad class file: C:\Program Files\Java\javafx-sdk-11.0.2\lib\javafx.graphics.jar(javafx/application/Application.class)
    class file has wrong version 54.0, should be 52.0
    Please remove or make sure it appears in the correct subdirectory of the classpath.

我从以下链接获取项目：

https://github.com/openjfx/samples/tree/master/IDE/IntelliJ/Non-Modular/Maven

我使用JRE 11。这是我的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>

    <groupId>org.openjfx</groupId>
    <artifactId>hellofx</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>hellofx</name>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <mainClass>org.openjfx.MainApp</mainClass>
    </properties>

    <organization>
        <!-- Used as the 'Vendor' for JNLP generation -->
        <name>Your Organisation</name>
    </organization>

    <dependencies>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-controls</artifactId>
            <version>11.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-fxml</artifactId>
            <version>11.0.2</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                    <release>11</release>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.6.0</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>java</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <mainClass>org.openjfx.MainApp</mainClass>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

顺便说一下，从IntelliJ构建示例JavaFX Application并添加javafx-sdk-11.0.2作为依赖项会产生完全相同的错误。

Answer 1

我也有同样的问题，

它只是通过删除org文件夹来解决。

C:\Temp\JavaCABuild\org\openqa\selenium\support\ui\Duration。班

Answer 2

我过去也有过类似的问题。问题是机器上安装了java8，maven使用了java8，默认情况下使用了java11。解决方案是确保JAVA_HOME指向java11安装。您可以运行mvn-X来查看哪个jvm用于运行maven，哪个javac用于编译代码：

$ mvn  -X clean package
Apache Maven 3.5.4 (Red Hat 3.5.4-5)
Maven home: /usr/share/maven
Java version: 1.8.0_272, vendor: Red Hat, Inc., runtime: /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.272.b10-4.el8.x86_64/jre
Default locale: en_US, platform encoding: ANSI_X3.4-1968
OS name: "linux", version: "4.18.0-240.el8.x86_64", arch: "amd64", family: "unix"

...
... java.home=/usr/lib/jvm/java-11-openjdk-11.0.9.11-3.el8.x86_64 ...

Answer 3

我有这个错误，我通过添加

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>10</source>
                <target>10</target>
                <encoding>UTF-8</encoding>
            </configuration>
        </plugin>
        <plugin>
            <!-- Build an executable JAR -->
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>3.1.0</version>
            <configuration>
                <archive>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <classpathPrefix>lib/</classpathPrefix>
                        <mainClass>Main</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>

到pom文件