Description of problem:

Our Java 8 application (not yet ported to Java 11) uses jna.

Installed it from jna rpm. Get this...

java.lang.UnsupportedClassVersionError: com/sun/jna/Library has been compiled by a more recent version of the Java Runtime (class file version 53.0), this version of the Java Runtime only recognizes class file versions up to 52.0

... i.e. jna in the rpm is only compatible with Java 9, not java 8.

java-1.8.0-openjdk is (apparently) still supported in el9, so the jna rpm should contain a jar with Java 8 compatibility. It doesn't.


Version-Release number of selected component (if applicable):
Name         : jna
Version      : 5.6.0
Release      : 6.el9
Architecture : x86_64
Size         : 279 k
Source       : jna-5.6.0-6.el9.src.rpm
Repository   : rhel-9-for-x86_64-appstream-rpms

How reproducible:
Always

Steps to Reproduce:
1. install jna rpm on RHEL9
2. install java-1.8.0-openjdk (etc)
3. run Java application using jna in java-1.8.0

Actual results:
java.lang.UnsupportedClassVersionError: com/sun/jna/Library has been compiled by a more recent version of the Java Runtime (class file version 53.0), this version of the Java Runtime only recognizes class file versions up to 52.0

Expected results:
Application runs normally, without error

Additional info:
I got jna-5.6.0-6.el9.src.rpm and rebuilt it, sure enough it goes...

-dynamic-properties:
...
     [echo] Java version 11.0.18, compatibility: 9, ant: 11
     [echo] JNA version 5.6.0, native 6.1.0, android 5060099
     [echo] OpenJDK 64-Bit Server VM (Red Hat, Inc., 11.0.18+10-LTS)

build.xml includes this...
  <condition property="compatibility" value="1.6" else="9">
    <matches pattern="^1\.\d+$" string="${ant.java.version}"/>
  </condition>

Java 11 should be able to produce 1.6 compatible Jars, yea?

So that regex is wrong, for Java version 11.0.18 it should be selecting 1.6, not 9, so that it builds a jar that's still compatible with the (still supported) Java 8.