language-java SKILL.md skillA
language-java from lugassawan/swe-workbench is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add lugassawan/swe-workbench/language-java@git:20260828.71a6399Pins git:20260828.71a6399 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- lugassawan/swe-workbench
- Path
skills/language-java/SKILL.md- Versions recorded
- 5
- Latest version
- git:20260828.71a6399, committed Aug 28, 2026
- First version recorded
- Jun 5, 2026
- Size
- 5,523 bytes
- Repository stars
- 3
- License
- MIT
Java idioms — records, sealed types, virtual threads, and JDK 21+ patterns. Auto-load when working with .java files, pom.xml, build.gradle, or when the user mentions Java, JVM, Spring, Maven, Gradle, sealed classes, or virtual threads.
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
## Records and sealed types
Modern Java models data without boilerplate.
```java
record Point(double x, double y) {}
sealed interface Shape permits Circle, Rectangle {}
record Circle(Point center, double radius) implements Shape {}
record Rectangle(Point topLeft, Point bottomRight) implements Shape {}
```
- Use `record` for immutable data carriers — equals, hashCode, toString, and accessors for free.
- `sealed` closes a hierarchy; exhaustive `switch` replaces `instanceof` chains.
```java
double area = switch (shape) {
case Circle c -> Math.PI * c.radius() * c.radius();
case Rectangle r -> Math.abs(r.bottomRight().x() - r.topLeft().x())
* Math.abs(r.bottomRight().y() - r.topLeft().y());
};
```
## Optional and null discipline
- Return `Optional<T>` from methods that may have no result; never use it as a field or parameter type.
- `Optional` is not a null check replacement — it signals "absence is a valid outcome."
- Annotate parameters and fields with `@NonNull` / `@Nullable` for static analysis.
- Jackson populates `List<T>` with literal nulls from valid JSON (`{"content":[null]}`) regardless
…Read the whole file at its exact version.
How to install
mdr add lugassawan/swe-workbench/language-java@sha256:73b4a466302753f5The line at the top of this page pins the label git:20260828.71a6399, 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_ylpiazp4dufxwsi6)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, between Jun 5, 2026 and Aug 28, 2026, about one every 21 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260828.71a6399 latest | 2026-08-28 | 71a6399 | 5,523 B | A | view · diff |
| git:20260815.60d7983 | 2026-08-15 | 60d7983 | 5,541 B | A | view · diff |
| git:20260719.e1f78e0 | 2026-07-19 | e1f78e0 | 4,977 B | A | view · diff |
| git:20260623.a686e99 | 2026-06-23 | a686e99 | 4,602 B | A | view · diff |
| git:20260605.400b074 | 2026-06-05 | 400b074 | 4,393 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 (5523 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
lugassawan/swe-workbench · 3 stars · license MIT · pushed 2026-11-07 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_ylpiazp4dufxwsi6 GET https://markdownregistry.com/api/v1/resolve?ref=lugassawan/swe-workbench/language-java GET https://markdownregistry.com/api/v1/blob/73b4a466302753f512dd141e95dc9eee5d9eab8a0b5dcf98b6230abd545e1ce3
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.