java-migration SKILL.md skillA
java-migration from decebals/claude-code-java is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add decebals/claude-code-java/java-migration@git:20260828.702770aPins git:20260828.702770a in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- decebals/claude-code-java
- Path
skills/java-migration/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260828.702770a, committed Aug 28, 2026
- Size
- 15,115 bytes
- Repository stars
- 759
- License
- MIT
Guide for upgrading Java projects between major versions (8→11→17→21→25). Use when user says "upgrade Java", "migrate to Java 25", "update Java version", or when modernizing legacy projects.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Java Migration Skill
Step-by-step guide for upgrading Java projects between major versions.
## When to Use
- User says "upgrade to Java 25" / "migrate from Java 8" / "update Java version"
- Modernizing legacy projects
- Spring Boot 2.x → 3.x → 4.x migration
- Preparing for LTS version adoption
## Migration Paths
```
Java 8 (LTS) → Java 11 (LTS) → Java 17 (LTS) → Java 21 (LTS) → Java 25 (LTS)
│ │ │ │ │
└──────────────┴───────────────┴──────────────┴───────────────┘
Always migrate LTS → LTS
```
---
## Quick Reference: What Breaks
| From → To | Major Breaking Changes |
|-----------|------------------------|
| 8 → 11 | Removed `javax.xml.bind`, module system, internal APIs |
| 11 → 17 | Sealed classes (preview→final), strong encapsulation |
| 17 → 21 | Pattern matching changes, `finalize()` deprecated for removal |
| 21 → 25 | Security Manager removed, Unsafe methods removed, 32-bit dropped |
---
## Migration Workflow
### Step 1: Assess Current State
```bash
# Check current Java version
java -version
# Check compiler target in Maven
grep -r "maven.compiler" pom.xml
…Read the whole file at its exact version.
How to install
mdr add decebals/claude-code-java/java-migration@sha256:a3e398c6d9bce8e1The line at the top of this page pins the label git:20260828.702770a, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_ay5egkmjfcuubpf4)
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Versions
The registry has recorded 1 version of this file, committed on Aug 28, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (15115 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
decebals/claude-code-java · 759 stars · license MIT · pushed 2026-09-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ay5egkmjfcuubpf4 GET https://markdownregistry.com/api/v1/resolve?ref=decebals/claude-code-java/java-migration GET https://markdownregistry.com/api/v1/blob/a3e398c6d9bce8e14544b0434b683ea6f1d11ea998ee8c51d70b08c1b2d631f7
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.