gunnarmorling / awesome-annotation-processing

A curated list of resources related to the Java annotation processing API (JSR 269)

Hello Stranger 👋!

My name is Gunnar. I am an open-source software engineer, currently working at Decodable, involved with data streaming based on Apache Flink. Before joining Decodable, I spent ten years at Red Hat, where I led the Debezium project, a platform for change data capture.

I have been a long-time committer to multiple open-source projects, including Debezium, Hibernate, kcctl 🧸, JfrUnit, MapStruct and Deptective; I also serve as the spec lead for Bean Validation 2.0 (first at the JCP, now under the Jakarta EE umbrella at the Eclipse Foundation).

Named a Java Champion, I enjoy presenting at conferences. I have spoken at events such as QCon, JavaOne, Red Hat Summit, JavaZone, JavaLand, Kafka Summit, Current, Flink Forward, and Data Council. Here are some recordings from talks over the last few years:

• Real-time Change Stream Processing with Apache Flink
• Keep Your Cache Always Fresh with Debezium!
• Taming Kafka Connect with kcctl
• Open-source Change Data Capture With Debezium
• Continuous Performance Regression Testing with JfrUnit
• To the Moon and Beyond With Java 17 APIs!

Occasionally, I blog about topics related to software engineering. Here are some popular posts:

• The One Billion Row Challenge 1️⃣🐝🏎️
• Getting Started With Java Development in 2023 — An Opinionated Guide
• The Code Review Pyramid
• What's in a Good Error Message?
• The Wonders of Postgres Logical Decoding Messages (on infoq.com)
• Saga Orchestration for Microservices Using the Outbox Pattern (on infoq.com)

awesome-annotation-processing's Issues

Maybe add JStachio?

Hi folks. I have new annotation processing project. https://github.com/jstachio/jstachio

I posted it on reddit (I know gunnar and @rbygrave are sometimes on reddit so maybe you guys saw it). I plan on early releasing today or Monday to Maven Central. Feel free to wait till then and I will add a comment once that happens.

I wanted to post early to see if there were any other requirements. EDIT the other reason is I am not sure if I should also add this the tools section.

JStachio is kind of a double APT project in that it uses the annotation processing framework to generate typesafe Mustache templates for web development BUT it can also be used for code generation which is usually useful for other APT projects. (perhaps MapStruct will use it instead of freemarker someday... I'm kidding freemarker is pretty awesome :) ).

I plan on some point making a JStachio option that will require zero runtime and thus no need to maven shade for annotation processors.

Potential new compiler testing tool for Java 11+

Hello!

I am currently working on a project that aims to implement compiler testing facilities for Java 11 and newer. Was wondering if this would be useful to add to the list eventually if you are interested.

Don't want to come across as making unwanted advertising, as that is definitely not my aim, but feedback from anyone who is interested in the mean time would always be welcome and useful to me, which is why I decided to ask.

The primary aim is to provide an interface that is compatible with the most bleeding edge of JDK releases to enable writing forwards-compatible and future proof annotation processors and plugins. It can also be used to integration test generated source code from codegen libraries. Additionally, you can make use of classloaders directly for generated code -- allowing you to immediately load classes generated from code under test into memory and use them with the reflection API or via dynamic typing in languages like Apache Groovy.

The project itself is still under development, but it has a few additional aims that I found the Google compiler testing module I used to work with didn't seem to support. Specifically this includes providing full JPMS support, allowing support for alternative compiler implementations other than javac, JUnit5 integration, etc. It also makes use of actual file systems that can be accessed from outside the filer API since many annotation processor libraries tend to do this. This is implemented using JIMFS by default which is effectively a pure Java RAM disk. However, a java.io.File-compatible API is also supported.

I am also looking for candidates for compiler plugins and annotation processors that will make for good acceptance tests on my side. The JSR-199 compiler plugin can be a little ambiguous in places and some annotation processor libraries can use compiler internals in surprising ways, so one of my aims is to have a large number of acceptance tests for various libraries in the repo that are run on every build to ensure no surprising behaviour has been missed. At the time of writing, I am currently testing against google autofactory, google autoservice, google autovalue, checkerframework, google dagger, spring indexer, spring boot autoconfiguration processor, spring boot configuration processor, mapstruct, lombok, manifold, and immutables.

Project is over at https://github.com/ascopes/java-compiler-testing. I aim to have a stable release by March if not sooner.

If you are interested then that would be fantastic, but if you are not, then no worries at all. Thought I would ask though! Thanks in advance!