VS Code - Support the Oracle Java Platform Extension

Expected Behavior

Oracle has recently introduced a Java Platform Extension for Visual Studio Code. It would be great if the Spring Boot Tools extension could work with it rather than requiring the Red Hat Language Support for Java extension. Perhaps there could be a way to support both and dynamically pick the extension installed in the workspace, so that users can decide what to use.

Current Behavior

The Spring Boot Tools extension doesn't work with the Oracle Java Platform Extension, which currently means it's not possible to work with Spring Boot applications on Java 21.

Context

The Oracle Java Platform Extension has the ability to always support the latest Java versions, including preview features (since it's based on javac). At the moment, it's the only VS Code extension which supports Java 21. Spring Boot Tools depends on the Red Hat Language Support for Java extension, which doesn't support Java 21 yet (pull request in progress which will add support for the stable features in Java 21: https://github.com/redhat-developer/vscode-java/pull/3314#issuecomment-1758462219, thanks @cypher256 for the heads-up). Preview features are planned to be supported at the end of the year based on the needed changes in the upstream Eclipse JDT. As a result, it's not possible to run Spring Boot applications with Java 21 at the moment when using Visual Studio Code and extensions from the Marketplace.

No files or tests are named. Start by locating the Spring Boot Tools integration that currently requires Red Hat Language Support for Java, then compare it with the Oracle Java Platform Extension's available VS Code APIs. Define workspace selection between the two providers and verify that Spring Boot applications work with the Oracle extension, including Java 21.