Question about commons-fileupload2-core-2.0.0-M2 working with Java 8

Hi,
I have a question about commons-fileupload2-core-2.0.0-M2 working with Java
8.
In our current application, we call commons-fileupload 1.5 working with
Java 8 to upload files.
Recently I tried to migrate to commons-fileupload2-core-2.0.0-M2, however,
it reports the following error:
[WARNING ] CWPMI2005W: The MicroProfile Metrics exception mapper detected
and is handling an unhandled exception from the JAX-RS application.

                                   java.lang.UnsupportedClassVersionError:
JVMCFRE199E bad major version 55.0 of
class=org/apache/commons/fileupload2/javax/JavaxServletFileUpload, the
maximum supported major version is 52.0; offset=6
        at java.lang.ClassLoader.defineClassImpl(Native Method)
        at java.lang.ClassLoader.defineClassInternal(ClassLoader.java:399)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:360)
        at
com.ibm.ws.classloading.internal.AppClassLoader.definePackageAndClass(AppClassLoader.java:435)
        at [internal classes]
        ......
        at sun.reflect.GeneratedMethodAccessor1015.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Method.java:508)
        at
com.ibm.ws.jaxrs20.server.LibertyJaxRsServerFactoryBean.performInvocation(LibertyJaxRsServerFactoryBean.java:649)
        at [internal classes]
        at
org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:70)
        at
com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:203)
        at [internal classes]


If I change to Java 21, then it works.

It is strange as the following Apache sites claim that it supports Java 8
https://commons.apache.org/proper/commons-fileupload/download_fileupload.cgi
https://commons.apache.org/proper/commons-fileupload/migration.html

Could you please help to investigate why commons-fileupload2-core-2.0.0-M2
does not support Java 8?
Thanks!

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