Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/mickeyyaya/refactoring-skills/java-review-patternsnpx skills add mickeyyaya/refactoring-skills --skill java-review-patternsgit clone --depth 1 https://github.com/mickeyyaya/refactoring-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/mickeyyaya/refactoring-skills/java-review-patterns)<a href="https://agentmods.dev/skills/mickeyyaya/refactoring-skills/java-review-patterns"><img src="https://agentmods.dev/badge/skills/mickeyyaya/refactoring-skills/java-review-patterns.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00082 | $0.04476 |
| Opus 5 | $0.00041 | $0.02238 |
| Sonnet 5 | $0.00016 | $0.00895 |
| Haiku 4.5 | $0.00008 | $0.00448 |
Grade A, and why
java-review-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 451 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Java Code Review Patterns
Overview
Java's size and long history create a distinct review challenge: the language has grown from Java 1 to Java 21 without removing legacy APIs, leaving reviewers to distinguish safe modern idioms from outdated patterns still present in production codebases.
Three forces drive Java-specific review mistakes. First, null is pervasive — NullPointerException remains the most common runtime crash, and Optional was introduced in Java 8 to address this but is frequently misused. Second, the Stream API enables elegant functional pipelines but introduces subtle bugs when side effects, infinite sequences, or parallelism are mixed in carelessly. Third, Java's threading model predates structured concurrency, and the synchronized keyword is still widely used, often with scope wider than necessary, while newer tools like CompletableFuture introduce their own error-swallowing traps.
Load this skill when reviewing any Java PR that touches service logic, data access, background tasks, or concurrent processing. Cross-reference review-accuracy-calibration before posting — Java has moderate false positive risk in the generics and concurrency sections, where correct-looking code can be intentionally chosen over the more idiomatic form.
Quick Reference
| Review Dimension | Severity | Primary Red Flag |
|---|---|---|
| Optional.get() without isPresent | HIGH | opt.get() without guard — throws NoSuchElementException |
| Optional as field or parameter | MEDIUM | Optional<T> stored in a struct or passed as method arg |
| Null returned where Optional expected | MEDIUM | Method declared to return Optional but returns null |
| Side effect in stream pipeline | HIGH | .forEach(list::add) or mutation inside .map() |
| Infinite stream without limit | HIGH | Stream.iterate(...) with no .limit() or .takeWhile() |
| Heavy work in parallel stream | MEDIUM | .parallelStream() on CPU-bound ops sharing a common pool |
| synchronized scope too wide | MEDIUM | Entire method synchronized when only 3 lines need a lock |
| CompletableFuture swallowed error | HIGH | .thenApply(...) chain with no .exceptionally() or .handle() |
| ThreadLocal not cleaned up | HIGH | ThreadLocal.set() in a request handler with no remove() |
| Raw generic type | MEDIUM | List list = new ArrayList() — unchecked operations |
| Mutable collection returned | MEDIUM | return this.items exposes internal state directly |
| Checked exception in lambda | MEDIUM | Checked exception caught and swallowed inside a lambda |
| Static mutable state | HIGH | private static List<X> mutated by instance methods |
| Resource not in try-with-resources | HIGH | Connection c = ds.getConnection() outside try-with-resources |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 4d ago First seen · 451 lines · 82 tokens per session scan A 5ec7982bb600
java-review-patterns is a skill published in the GitHub repository mickeyyaya/refactoring-skills (6 stars, last pushed 5mo ago), licensed MIT. It adds 82 tokens to every session and 4,476 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
azure-ai-anomalydetector-java
Build anomaly detection applications with Azure AI Anomaly Detector SDK for Java. Use when implementing univariate/multivariate anomaly detection, time-series analysis, or AI-powered monitoring.
azure-communication-chat-java
Build real-time chat applications with Azure Communication Services Chat Java SDK. Use when implementing chat threads, messaging, participants, read receipts, typing notifications, or real-time chat features.
azure-communication-common-java
Azure Communication Services common utilities for Java. Use when working with CommunicationTokenCredential, user identifiers, token refresh, or shared authentication across ACS services.
union-type-wrappers
Add typed getters and setters over BinaryData properties that represent TypeSpec union types in generated Java models. Use when generated classes expose BinaryData for union-typed fields and you need ergonomic, type-safe accessors instead.
azure-ai-agents-persistent-java
Azure AI Agents Persistent SDK for Java. Low-level SDK for creating and managing AI agents with threads, messages, runs, and tools. Triggers: "PersistentAgentsClient", "persistent agents java", "agent threads java", "agent runs java", "streaming agents java".
search-m2
Search for Java classes inside Maven dependencies in /.m2. Use when the user asks to locate classes or inspect JARs. Cross-reference pom.xml files in the current directory to resolve dependency names/versions.