java-best-practice-checker
by PromptSpace
Expert Java code auditor for SE 8–24, flagging performance leaks, threading risks, and modernization gaps.
- Modernize legacy Java 8 code to use Records, Switch Expressions, and var.
- Identify thread-safety hazards and manual lock contention in concurrent code.
- Optimize String handling and Collection choices for high-throughput apps.
Free
One-time purchase
Included in download
- Downloadable skill package
- Works with OpenClaw, Cursor
- Instant install
See it in action
🔴 Issue 1 — Concatenation in loop (Report.build)
Each += allocates a new String; O(n²) performance.
// ✅ Fix
StringBuilder sb = new StringBuilder();
for (var item : list) { sb.append(item); }
return sb.toString();
| # | Location | Category | Issue | Severity |
|---|---|---|---|---|
| 1 | Report.build() | Strings | Loop concat | 🔴 High |java-best-practice-checker
by PromptSpace
Expert Java code auditor for SE 8–24, flagging performance leaks, threading risks, and modernization gaps.
Free
One-time purchase
⚡ Skill ready to install in Claude Code, Gemini CLI, or any MCP-compatible client. Read the install guides →
Included in download
- Downloadable skill package
- Works with OpenClaw, Cursor
- Instant install
See it in action
🔴 Issue 1 — Concatenation in loop (Report.build)
Each += allocates a new String; O(n²) performance.
// ✅ Fix
StringBuilder sb = new StringBuilder();
for (var item : list) { sb.append(item); }
return sb.toString();
| # | Location | Category | Issue | Severity |
|---|---|---|---|---|
| 1 | Report.build() | Strings | Loop concat | 🔴 High |About This Skill
What it does
This skill performs an exhaustive, automated audit of Java source code ranging from SE 8 through the latest SE 24 features. It acts as a specialized static analysis engine that identifies violations of modern best practices, concurrency hazards, and architectural anti-patterns.
Why use this skill
Unlike standard linters, this skill provides deep context and "why it matters" explanations for every flag. It helps developers modernize legacy codebases by suggesting Java 21+ features like Record Patterns and Virtual Threads, while simultaneously catching classic "silent killers" like String Pool bypasses and thread-safety bugs in Singletons.
Supported areas
- Modern Syntax: Pattern matching (SE 21), Unnamed variables (SE 22), Stream Gatherers (SE 24).
- Core Performance: String handling, wrapper class caching, and JIT-friendly coding patterns.
- Collections: Deep analysis of the Collections Framework and the new SequencedCollection API.
- Architecture: Dependency injection, OOP encapsulation, and Design Pattern implementations.
- JVM Internals: Garbage collection awareness, memory leak detection, and resource management.
The Output
The skill generates a structured report featuring severity-coded issues (🔴/🟡/🟢), root-cause analysis, and side-by-side "Fix" code blocks. Every review concludes with a professional Summary Table for quick triage by lead developers or PR reviewers.
Use Cases
- Modernize legacy Java 8 code to use Records, Switch Expressions, and var.
- Identify thread-safety hazards and manual lock contention in concurrent code.
- Optimize String handling and Collection choices for high-throughput apps.
- Ensure proper resource cleanup and prevent JVM memory leaks.
How to Install
mkdir -p ~/.claude/skills/java-best-practice-checker && curl -s -X POST 'https://api.promptspace.in/api/skills/java-best-practice-checker/install' | python3 -c "import sys,json; sys.stdout.write(json.load(sys.stdin).get('installInstructions') or '')" > ~/.claude/skills/java-best-practice-checker/SKILL.mdFree skills install directly. Paid skills require purchase - use the download button above after buying.
Reviews
Security Scanned
Passed automated security review
Permissions
No special permissions declared or detected
OpenClaw, Cursor, Claude Code, Codex CLI
Creator
PromptSpace
We build AI agent skill packages for content creators. Specializing in Chinese social media automation.