121-java-object-oriented-design SKILL.md skillA
121-java-object-oriented-design from jabrena/plinth is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add jabrena/plinth/121-java-object-oriented-design@v0.19.0Pins v0.19.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- jabrena/plinth
- Path
skills/121-java-object-oriented-design/SKILL.md- Versions recorded
- 6
- Latest version
- v0.19.0, committed Sep 26, 2026
- First version recorded
- Apr 26, 2026
- Size
- 8,358 bytes
- Repository stars
- 461
- License
- Apache-2.0
Use when reviewing, improving, or refactoring Java object-oriented design, including applying SOLID, DRY, or YAGNI; improving classes and interfaces; correcting encapsulation, inheritance, or polymorphism; resolving God Class, Feature Envy, or Data Clumps; and improving object creation, methods, or exception contracts. Triggers include review Java OOD, refactor Java OOD, improve Java OOD, fix OOP misuse, and identify Java code smells. Part of Plinth Toolkit.
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 Object-Oriented Design Guidelines Review and improve Java code using focused object-oriented design references selected after assessing the request and affected code. **What is covered in this Skill?** - Fundamental design principles (SOLID, DRY, YAGNI) - Class and interface design: composition over inheritance, immutability, accessibility minimization, accessor methods - Core OOP concepts: encapsulation, inheritance, polymorphism - Object creation patterns: static factory methods, Builder, Singleton, dependency injection, avoiding unnecessary objects - OOD code smells: God Class, Feature Envy, Inappropriate Intimacy, Refused Bequest, Shotgun Surgery, Data Clumps - Method design: parameter validation, defensive copies, careful signatures, empty collections over nulls, Optional usage - Exception handling: checked vs. runtime exceptions, standard exceptions, failure-capture messages, no silent ignoring **Scope:** Classify the applicable OOD concerns first, then load only the focused references needed for those concerns. Load multiple references when a refactoring crosses concern boundaries. ## Constraints …
Read the whole file at its exact version.
How to install
mdr add jabrena/plinth/121-java-object-oriented-design@sha256:835e4fc793218ee6The line at the top of this page pins the label v0.19.0, 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_uuthjeoc2vfu7ic2)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 6 versions of this file, between Apr 26, 2026 and Sep 26, 2026, about one every 31 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v0.19.0 latest | 2026-09-26 | 9569c35 | 8,358 B | A | view · diff |
| v0.18.0 | 2026-08-01 | 26b0e71 | 8,358 B | A | view · diff |
| v0.17.0 | 2026-07-10 | aaee915 | 8,358 B | A | view · diff |
| v0.16.0 | 2026-06-15 | b73c9d3 | 8,369 B | A | view · diff |
| v0.15.0 | 2026-05-29 | a800339 | 3,773 B | A | view · diff |
| v0.15.0-SNAPSHOT | 2026-04-26 | 819f349 | 3,782 B | A | view |
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 (8358 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
jabrena/plinth · 461 stars · license Apache-2.0 · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_uuthjeoc2vfu7ic2 GET https://markdownregistry.com/api/v1/resolve?ref=jabrena/plinth/121-java-object-oriented-design GET https://markdownregistry.com/api/v1/blob/835e4fc793218ee65581207c5531b418725490fab30f2f9ee951c74ea11c3b5a
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.