GitHub Copilot coding agent runs in an ephemeral GitHub Actions environment where it can build your code, run tests, and execute tools. By default, it uses the pre-installed Java version on the runner — but what if your project needs a specific version like JDK 25?
In this post, I’ll show you how to configure Copilot coding agent’s environment to use any Java version, including the latest JDK 25, ensuring that Copilot can successfully build and test your Java projects.