plexus-compiler-aspectj 2.12.1 doesn't suppprt JDK 1.8

[tia-ru]

plexus-compiler-aspectj 2.12.1 doesn't suppprt JDK 1.8
Version 2.12.0 supports JDK 1.8

org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0

Caused by: java.lang.UnsupportedClassVersionError: org/eclipse/core/runtime/OperationCanceledException has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
at java.lang.ClassLoader.defineClass1 (Native Method)
at java.lang.ClassLoader.defineClass (ClassLoader.java:756)
at java.security.SecureClassLoader.defineClass (SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass (URLClassLoader.java:473)
at java.net.URLClassLoader.access$100 (URLClassLoader.java:74)
at java.net.URLClassLoader$1.run (URLClassLoader.java:369)
at java.net.URLClassLoader$1.run (URLClassLoader.java:363)
at java.security.AccessController.doPrivileged (Native Method)
at java.net.URLClassLoader.findClass (URLClassLoader.java:362)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf (ClassRealm.java:425)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass (SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass (ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass (ClassRealm.java:247)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass (ClassRealm.java:239)
at org.codehaus.plexus.compiler.ajc.AspectJCompiler.compileInProcess (AspectJCompiler.java:473)
at org.codehaus.plexus.compiler.ajc.AspectJCompiler.performCompile (AspectJCompiler.java:329)
at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute (AbstractCompilerMojo.java:1209)
at org.apache.maven.plugin.compiler.CompilerMojo.execute (CompilerMojo.java:198)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.builder.multithreaded.MultiThreadedBuilder$1.call (MultiThreadedBuilder.java:190)

[slachiewicz]

AspectJ compiler build system requirements
Since 1.9.7, the AspectJ compiler ajc (contained in the aspectjtools library) no longer works on JDKs 8 to 10. The minimum compile-time requirement is now JDK 11 due to upstream changes in the Eclipse Java Compiler (subset of JDT Core), which AspectJ is a fork of. You can still compile to legacy target versions as low as Java 1.3 when compiling plain Java code or using plain Java ITD constructs which do not require the AspectJ runtime aspectjrt, but the compiler itself needs JDK 11+. Just like in previous AspectJ versions, both the runtime aspectjrt and the load-time weaver aspectjweaver still only require JRE 8+.

[tia-ru]

We are using ajc 1.9.7. It's the last version that works on JDK 8.
In case of ajc 1.9.9.1 API used plexus-compiler-aspectj is comatible with 1.9.7 it would be very helpful for many projects that are still using JDK 8 to compile plexus-compiler-aspectj with ajc 1.9.7 and byte code target 1.8.
At least it's strage to break backward compatibility in minor version 2.12.1.
Actually I need bug fixes in aspect j-maven-plugin which uses plexus-compiler-aspectj under the hood. It allows to use any version of ajc as required by a project.

[slachiewicz]

I believe this was not intentional. Feel free to open pr with fix to restore compatibility

[olamy]

maybe you can simply stick with plexus-compiler-aspectj 1.12.0 and upgrade the aspectj dependency in your pom if you need it. until you can use a more modern java version.

[tia-ru]

UPD. I have edit my comments to clarify that right version under discussion is 2.12.0, not 1.12.0

2.12.0 has no bugfixes important for me.
AJC 1.9.7 itself can run on JDK 1.8, but the plexus adapter for AJC cannot. I believe javac -target 1.8 to compile plexus-compiler-aspectj should restore JDK 1.8 compatibility and be able to launch more recent AJC versions. That was the case at the time of writing the issue, at least.

[slachiewicz]

could You check if version from this branch #278 works?

[olamy]

1.12.0 has no bugfixes important for me. AJC 1.9.7 itself can run on JDK 1.8, but the plexus adapter for AJC cannot. I believe javac -target 1.8 to compile plexus-compiler-aspectj should restore JDK 1.8 compatibility and be able to launch more recent AJC versions. That was the case at the time of writing the issue, at least.

so just simply do not upgrade if you do not need new version?
we can't simply keep compatibility for old java version forever! (not even supported anymore)

you can maybe get it working using something such:

      <plugin>
        <groupId>org.apache.maven.plugins</groupId>     
        <artifactId>maven-compiler-plugin</artifactId>
        <version></version>
        <configuration>
          <compilerId>aspectj</compilerId>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.codehaus.plexus</groupId>
            <artifactId>plexus-compiler-api</artifactId>
            <version>${plexus.compiler.version}</version>
          </dependency>
          <dependency>
            <groupId>org.codehaus.plexus</groupId>
            <artifactId>plexus-compiler-aspectj</artifactId>
            <version>${plexus.compiler.version}</version>
          </dependency>
          <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>${aspectj.version}</version>
          </dependency>
          <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjtools</artifactId>
            <version>${aspectj.version}</version>
          </dependency>
        </dependencies>
      </plugin>

with plexus.compiler.version=1.12.0 and aspectj.version=1.9.9.1 (if you really want the new version which I guess you need otherwise you would not open an issue if you do not need any upgrade)

[tia-ru]

@slachiewicz The branch #278 works fine with JDK 8. Test project:
test-plexus-aspectj.zip
FYI the branch is not compatible with maven-compiler-plugin 3.10.1

@olamy I overload aspectj version to 1.9.7 by the way that you point and it works with plexus-compiler-aspectj 2.12.1 on JDK 8.
Thank you, it resovles my issue.