Java Upgrade

Help upgrade a Java project step by step and adopt new language features safely.

Need a more powerful, automated upgrade?

The Microsoft plugin modernize-java ("GitHub Copilot modernization - Java Upgrade CLI Plugin", also listed in this repository's plugins/external.json) upgrades Java applications from the command line. It can:

• analyze the project, assess dependencies and generate a customizable upgrade plan you can review and edit;
• execute the plan to automatically transform the codebase;
• fix build issues and resolve migration errors during the upgrade, running test validations;
• validate the application against known CVEs after the upgrade;
• output a detailed summary (file changes, updated dependencies, test results, remaining issues) suitable for PRs or CI logs.

This skill provides lightweight, step-by-step guidance and works without the plugin; the plugin is the more powerful option for large or multi-step upgrades. It is a separate Microsoft plugin, not part of this repository's skills. To try it (see the plugin README for the recommended model):