upgrade

name	upgrade
description	Upgrade Java runtime versions, frameworks, and dependencies to their latest compatible releases

Upgrade

Upgrade Java runtime versions, frameworks, and dependencies.

Version-Specific Upgrade Guides

For detailed, JEP-by-JEP upgrade instructions, see the version-specific skills:

• Java 8 → 11 — Module system, removed Java EE modules, var, HTTP Client
• Java 11 → 17 — Records, Sealed Classes, Pattern Matching, Text Blocks
• Java 17 → 21 — Virtual Threads, Pattern Matching for switch, Record Patterns
• Java 21 → 25 — Flexible Constructors, Stream Gatherers, Class-File API

Steps

1. Analyze first — Scan the project structure, build files (pom.xml, build.gradle), and source code to determine current Java version, framework versions, and dependency versions.
2. Generate an upgrade plan — Produce a plan detailing what will be upgraded and what breaking changes to expect. Present the plan for review.
3. Apply changes incrementally — Make changes in logical groups:
   • Build configuration (Java version, plugin versions)
   • Dependencies (framework BOMs, library versions)
   • Source code (API changes, deprecated method replacements)
   • Configuration files (property renames, format changes)
4. Validate after each group — Run the build (mvn clean compile or gradle build) to confirm changes compile successfully. Run tests if available.
5. Check for vulnerabilities — After upgrading, scan for known vulnerabilities in the updated dependencies.

Guidelines

• Prefer incremental upgrades over large version jumps when the gap is significant.
• Always explain what changes are being made and why.
• If a build fails after changes, analyze the error and attempt to fix it before reporting.
• When multiple upgrade paths exist, present options and let the developer decide.