Menu

Individual skill

java-upgrade

Upgrade a Java project to a newer JDK (11 to 17, 17 to 21, 21 to 25) and adopt the new language and library features. Detects the current Java version from the build files, then loads only the matching per-version guide. Use when the user asks to upgrade Java, modernize Java code, or adopt records, sealed classes, pattern matching, virtual threads or other new Java features. For automated end-to-end upgrades see the modernize-java plugin.

skills/java-upgrade/SKILL.md

Read pinned source

Source commit edbecfa9099c4addae1f500cca1ac067204b30fd

What was checked

Matches the observed repository HEAD
Yes
Scanner rules are current
Yes
Repository scan complete
No
Skill scan complete
No
Observed behavior
Network or broad shell
Last checked
Nov 4, 2026

These are observations at the recorded commit, not a guarantee of safety. Review the source before running it.

Install this skill

Choose an agent in your Stack or copy a command below. Commands fetch the pinned commit and copy only this skill directory. Existing destinations are refused. Copying a command does not install anything.

An install command is unavailable: current rules, complete repository and skill scans, an eligible behavior level and a permitted license are required.

Repository context

Repository stars (not skill ratings)
40,889
Repository last updated
Nov 6, 2026
License
MIT

Observed agent integration: No specific integration evidence. Standard SKILL.md installation does not imply verified compatibility.

Files and excerpt

File metadata and permitted, redacted excerpts come from the recorded scan. Source links are pinned to that commit.

Browse files
Read excerpt

# 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`](https://github.com/microsoft/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.