AspectJ 1.9.9

AspectJ 1.9.9.1

Release info: 1.9.9.1 available 31-Mar-2022

Bugfix release for some compiler options related to the Java Platform Module System (JPMS) which were not working, most importantly --add-modules, --add-exports and --add-reads. See issue #145.

This probably was broken for a long time. AspectJ still is not boasting extensive JPMS support or test coverage, but this improvement seems substantial enough to justify a minor release, instead of keeping users waiting for the next regular release.

AspectJ 1.9.9

Release info: 1.9.9 available 24-Mar-2022

Please note that Bugzilla for issue management is deprecated and new issues should be filed as GitHub issues. The list of issues addressed for 1.9.9 can be found here:

New features

AspectJ 1.9.9 supports Java 18 and its final and preview features, such as:

Pattern matching for switch (preview 2)

Improvements

In annotation style aspects, asynchronous proceed() calls in @Around advice now works in threads created from within the advice. Previously, this was only working in native syntax aspects. There is still a limitation with regard to asynchronous proceed, if you do not create the thread in the advice but want to use e.g. an ExecutorService with its own thread pool. This still is not working in annotation style aspects, only in native syntax ones.

See issue #128 and pull request #132 for more details.

Code examples

You can find some sample code in the AspectJ test suite under the respective AspectJ version in which the features were first supported (possibly as JVM preview features):

Other changes and bug fixes

Fix a bug which led to NullPointerExceptions, if too many JAR archives were on the classpath. Too many here means the value of system property org.aspectj.weaver.openarchives (1,000 by default). The AspectJ compiler is meant to close archives upon cache exhaustion and then re-open them, if it needs them again later. Re-opening was broken, but now the compiler works reliably even for cache sizes as small as 20. See issue #125.
Improvements for if() pointcuts in annotation syntax, see issues #115, #120, #122.
Thanks to Andrey Turbanov for several clean code contributions.

AspectJ usage hints

AspectJ compiler build system requirements

Since 1.9.8, 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+.

Use LTW on Java 16+

Please note that if you want to use load-time weaving on Java 16+, the weaving agent collides with JEP 396 (Strongly Encapsulate JDK Internals by Default). Therefore, you need to set the JVM parameter --add-opens java.base/java.lang=ALL-UNNAMED in order to enable aspect weaving. This is due to the fact that the weaver uses internal APIs for which we have not found an adequate replacement yet when defining classes in different classloaders.

Update: As of AspectJ 1.9.21.1, --add-opens is no longer necessary. Please upgrade, if it bothers you too much.

Compile with Java preview features

For features marked as preview on a given JDK, you need to compile with ajc --enable-preview and run with java --enable-preview on that JDK.

Please note, that you cannot run code compiled with preview features on any other JDK than the one used for compilation. For example, records compiled with preview on JDK 15 cannot be used on JDK 16 without recompilation. This is a JVM limitation unrelated to AspectJ. Also, e.g. sealed classes are preview-1 on JDK 15 and preview-2 on JDK 16. You still need to recompile, no matter what.