groovy 警告：在 Ubuntu 下发生了非法反射访问操作

Question

与Groovy 相同的问题 - 警告：发生了非法反射访问操作，仅此而已

• 这是在 Ubuntu 21.10
• 最重要的是该解决方案（将--add-opens传递给 JVM），我无法让它为我工作。

$ groovy -version
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.codehaus.groovy.reflection.CachedClass (file:/usr/share/groovy/lib/groovy-2.4.21.jar) to method java.lang.Object.finalize()
WARNING: Please consider reporting this to the maintainers of org.codehaus.groovy.reflection.CachedClass
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Groovy Version: 2.4.21 JVM: 11.0.12 Vendor: Ubuntu OS: Linux

$ java -version
openjdk version "11.0.12" 2021-07-20
OpenJDK Runtime Environment (build 11.0.12+7-Ubuntu-0ubuntu3)
OpenJDK 64-Bit Server VM (build 11.0.12+7-Ubuntu-0ubuntu3, mixed mode, sharing)

$ java --add-opens java.base/java.lang=ALL-UNNAMED -version
openjdk version "11.0.12" 2021-07-20
OpenJDK Runtime Environment (build 11.0.12+7-Ubuntu-0ubuntu3)
OpenJDK 64-Bit Server VM (build 11.0.12+7-Ubuntu-0ubuntu3, mixed mode, sharing)

$ groovy --add-opens java.base/java.lang=ALL-UNNAMED -version
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.codehaus.groovy.reflection.CachedClass (file:/usr/share/groovy/lib/groovy-2.4.21.jar) to method java.lang.Object.finalize()
WARNING: Please consider reporting this to the maintainers of org.codehaus.groovy.reflection.CachedClass
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Caught: java.io.FileNotFoundException: /export/home/me/--add-opens (/export/home/me/--add-opens)
java.io.FileNotFoundException: /export/home/me/--add-opens (/export/home/me/--add-opens)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

$ apt-cache policy groovy
groovy:
  Installed: 2.4.21-1
  Candidate: 2.4.21-1
  Version table:
 *** 2.4.21-1 500
        500 http://archive.ubuntu.com/ubuntu impish/universe amd64 Packages
        500 http://archive.ubuntu.com/ubuntu impish/universe i386 Packages
        100 /var/lib/dpkg/status


$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 21.10
Release:        21.10
Codename:       impish

更新，我也尝试设置JAVA_OPTS ：

export JAVA_OPTS="--add-opens java.base/java.lang=ALL-UNNAMED"

$ groovy -version
Unrecognized option: --add-opens
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

如何摆脱该警告信息？

Answer 1

按照此处的说明进行操作： https://groovy-lang.org/install.html这将：

• 安装 sdkman
  • 管理多个 JDK 和扩展
• 在当前JDK中安装groovy

为我工作：

• openjdk 11.0.11 2021-04-20
• OpenJDK 运行环境（build 11.0.11+9-Ubuntu-0ubuntu2.20.04）
• OpenJDK 64-Bit Server VM (build 11.0.11+9-Ubuntu-0ubuntu2.20.04, 混合模式, 共享)

Answer 2

从 FileNotFound 异常中可以清楚地看出 --add-opens 没有用作 JVM 标志。 您是否尝试过设置 JAVA_OPTS？ 像这样：

export JAVA_OPTS="--add-opens java.base/java.lang=ALL-UNNAMED"
groovy --version

我没有得到和你一样的错误。 实际上，我仍然收到反射访问警告，而不是关于--add-opens无法识别的错误。 即使使用--illegal-access=permit我仍然会看到警告。 奇怪的。 我确定正在使用 JAVA_OPTS 值，因为如果我将其设置为无效标志，它会抱怨。

你有定义 JAVA_HOME 吗？ 我注意到 groovy 也选择了该值来选择 JVM。

使用 Java 17 我没有收到任何警告或错误。

Answer 3

It is more than a 'warning' for me: I cannot get Groovy scripts to run (on macOS) with the current JVM 9, much less 10. The workaround (until a compatible version of Groovy is available) is to install jenv and an Java的早期版本，所以你可以在需要的时候切换。