A Tool for Jakarta EE Package Renaming in Binaries

In a previous post, I laid out my thinking on how to approach the package renaming problem which the Jakarta EE community now faces. Regardless of whether the community chooses big bang or incremental, there are still existing artifacts in the world using the Java EE package names that the community will need to use together with the new Jakarta EE package names.

Tools are always important to take the drudgery away from developers. So I have put together a tool prototype which can be used to transform binaries such as individual class files and complete JARs and WARs to rename uses of the Java EE package names to their new Jakarta EE package names.

The tools is rule driven which is nice since the Jakarta EE community still needs to define the actual package renames for Jakarta EE 9. The rules also allow the users to control which class files in a JAR/WAR are transformed. Different users may want different rules depending upon their specific needs. And the tool can be used for any package renaming challenge, not just the specific Jakarta EE package renames.

The tools provides an API allowing it to be embedded in a runtime to dynamically transform class files during the class loader definition process. The API also supports transforming JAR files. A CLI is also provided to allow use from the command line. Ultimately, the tool can be packaged as Gradle and Maven plugins to incorporate in a broader tool chain.

Given that the tool is prototype, and there is much work to be done in the Jakarta EE community regarding the package renames, I have started a list of TODOs in the project' issues for known work items.

Please try out the tool and let me know what you think. I am hoping that tooling such as this will ease the community cost of dealing with the package renames in Jakarta EE.

PS. Package renaming in source code is also something the community will need to deal with. But most IDEs are pretty good at this sort of thing, so I think there is probably sufficient tooling in existence for handling the package renames in source code.