Java Design Patterns Reference
decebals/claude-code-java
A practical Java reference for Builder, Factory, Singleton, Strategy, Observer and other patterns, with a table matching problems to patterns.
A skill your agent uses when you need to refactor Java code for high performance — including memory/allocation reduction, CPU hot-path optimization, and syntax/API/control-flow improvements.
Install 145 Java Refactoring High Performance
$ npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install jabrena/plinth 145-java-refactoring-high-performance --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/jabrena/plinth.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/145-java-refactoring-high-performance .claude/skills/145-java-refactoring-high-performance && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "145-java-refactoring-high-performance" agent skill from https://github.com/jabrena/plinth/tree/main/skills/145-java-refactoring-high-performance into .claude/skills/145-java-refactoring-high-performance/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "145-java-refactoring-high-performance", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/jabrena/plinth/tree/main/skills/145-java-refactoring-high-performanceType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install jabrena/plinth 145-java-refactoring-high-performance --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jabrena/plinth.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/145-java-refactoring-high-performance .agents/skills/145-java-refactoring-high-performance && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "145-java-refactoring-high-performance" agent skill from https://github.com/jabrena/plinth/tree/main/skills/145-java-refactoring-high-performance into .agents/skills/145-java-refactoring-high-performance/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "145-java-refactoring-high-performance", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install jabrena/plinth 145-java-refactoring-high-performance --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jabrena/plinth.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/145-java-refactoring-high-performance .cursor/skills/145-java-refactoring-high-performance && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "145-java-refactoring-high-performance" agent skill from https://github.com/jabrena/plinth/tree/main/skills/145-java-refactoring-high-performance into .cursor/skills/145-java-refactoring-high-performance/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "145-java-refactoring-high-performance", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/jabrena/plinth.git --path skills/145-java-refactoring-high-performance--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install jabrena/plinth 145-java-refactoring-high-performance --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jabrena/plinth.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/145-java-refactoring-high-performance .gemini/skills/145-java-refactoring-high-performance && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "145-java-refactoring-high-performance" agent skill from https://github.com/jabrena/plinth/tree/main/skills/145-java-refactoring-high-performance into .gemini/skills/145-java-refactoring-high-performance/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "145-java-refactoring-high-performance", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install jabrena/plinth 145-java-refactoring-high-performanceInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/jabrena/plinth.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/145-java-refactoring-high-performance .github/skills/145-java-refactoring-high-performance && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "145-java-refactoring-high-performance" agent skill from https://github.com/jabrena/plinth/tree/main/skills/145-java-refactoring-high-performance into .github/skills/145-java-refactoring-high-performance/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "145-java-refactoring-high-performance", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install jabrena/plinth 145-java-refactoring-high-performance --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/jabrena/plinth.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/145-java-refactoring-high-performance .opencode/skills/145-java-refactoring-high-performance && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "145-java-refactoring-high-performance" agent skill from https://github.com/jabrena/plinth/tree/main/skills/145-java-refactoring-high-performance into .opencode/skills/145-java-refactoring-high-performance/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "145-java-refactoring-high-performance", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
145-java-refactoring-high-performance- GitHub stars
- 446
- Token cost
- ~937 tokens
- SKILL.md length
- 324 words
- Files
- 4 (incl. references)
- Skills in repo
- 124
- Repo updated
- First seen
- Licence
- Apache-2.0
At a glance
A skill your agent uses when you need to refactor Java code for high performance — including memory/allocation reduction, CPU hot-path optimization, and syntax/API/control-flow improvements.
- You need to refactor Java code for high performance — including memory/allocation reduction
- SKILL.md covers Constraints, When to use this skill, Workflow and Reference
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
- CPU hot-path optimization
What it does
145 Java Refactoring High Performance is an agent skill from jabrena/plinth. Use when you need to refactor Java code for high performance — including memory/allocation reduction, CPU hot-path optimization, and syntax/API/control-flow improvements. This should trigger for requests such as Review Java code for high performance; Optimize Java hot path; Reduce Java allocations; Improve Java latency/throughput. Part of Plinth Toolkit
Its SKILL.md is about 940 tokens, which your agent loads only when the skill is triggered. The skill folder holds 4 other files, including reference files (for example `references/145-refactoring-high-performance-java-code-syntax.md`, `references/145-refactoring-high-performance-java-cpu.md` and `references/145-refactoring-high-performance-java-memory-allocation.md`).
It sits in Development, covering Refactoring. It works with Java. The repository describes itself as: Plinth is an AI-native engineering toolkit for modern Java enterprise SDLC, built around reusable Commands, Agents, Skills, and MCP Servers. The licence is Apache-2.0.
When your agent uses it
- You need to refactor Java code for high performance — including memory/allocation reduction
- CPU hot-path optimization
- Syntax/API/control-flow improvements
- Requests such as Review Java code for high performance
Example prompts
- “/145-java-refactoring-high-performance”
What it can do on your machine
Read from SKILL.md and the folder at commit dca88dc. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
145 Java Refactoring High Performance loads about 937 tokens when it runs, and up to ~17k if it reads all its reference files. Until then it costs about 98 tokens; SKILL.md has 324 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from jabrena/plinth at commit dca88dc, republished under its Apache-2.0 licence (© jabrena). 324 words, ~937 tokens.
Download SKILL.mdSave it as
.claude/skills/145-java-refactoring-high-performance/SKILL.md (or your agent's skills folder). This skill also uses 3 other files; get the full folder from GitHub.- name
- 145-java-refactoring-high-performance
- description
- Use when you need to refactor Java code for high performance — including memory/allocation reduction, CPU hot-path optimization, and syntax/API/control-flow improvements. This should trigger for requests such as Review Java code for high performance; Optimize Java hot path; Reduce Java allocations; Improve Java latency/throughput. Part of Plinth Toolkit
- license
- Apache-2.0
- metadata.author
- Juan Antonio Breña Moral
- metadata.version
- 0.19.0
Java rules for High Performance
Identify and apply practical Java high-performance techniques using a measure-first approach, with emphasis on allocation reduction, data layout, concurrency discipline, and evidence-based validation.
What is covered in this Skill?
- Measure-first workflow for Java code optimization
- JVM/runtime-aware coding guidance
- Allocation reduction techniques with bad/good patterns
- CPU hot-path simplification and loop-level efficiency patterns
- Concurrency/backpressure and timeout/cancellation discipline
- I/O, parsing, and serialization efficiency patterns
- Persistence/query and caching strategy guidance
- Java-centric decision workflow: keep/revert based on measured impact
Scope: Practical optimization in application code and APIs. Apply only where profiling indicates real bottlenecks.
Constraints
Performance optimization must be evidence-driven and safe, focused on Java code changes that preserve correctness and maintainability.
- MEASURE-FIRST: Establish baseline behavior and identify Java code hot paths before optimization
- NO PREMATURE OPTIMIZATION: Only optimize code paths identified by profiling evidence
- BEFORE APPLYING: Read the relevant reference(s) for bad/good examples and measurement workflow
- EDGE CASE: If hotspot evidence is unclear, ask clarifying questions before changing code
When to use this skill
- Review Java code for high performance
- Optimize Java hot path
- Reduce Java allocations
- Improve Java latency
- Improve Java throughput
Workflow
- Identify Java hotspot and baseline behavior
Confirm the performance-sensitive Java path and baseline behavior before changing code.
- Select the relevant reference(s) by bottleneck
Pick and read only the reference(s) matching the observed hotspot: references/145-refactoring-high-performance-java-memory-allocation.md for allocation pressure, primitives vs. wrappers, escape analysis, collection sizing, data layout, and deduplication; references/145-refactoring-high-performance-java-cpu.md for CPU-bound hot paths, bit-level parsing, branchless arithmetic, loop unrolling, Unsafe caution, and SIMD/vectorization; references/145-refactoring-high-performance-java-code-syntax.md for code shape, lambdas, API return conventions, parsing syntax, I/O strategy, concurrency, and control-flow improvements.
- Apply targeted optimizations
Implement minimal, evidence-backed changes scoped to the chosen domain(s): memory/allocation, CPU/low-level, or code shape/control flow (and adjacent concurrency, I/O, and persistence/caching in Java code).
- Validate and compare code-level outcomes
Compare before/after behavior and keep only Java code changes with meaningful, verified gains.
Reference
For detailed guidance, examples, and constraints, see:
© jabrena, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 3 other files (references) in skills/145-java-refactoring-high-performance of jabrena/plinth.
- SKILL.md
- references/145-refactoring-high-performance-java-code-syntax.md
- references/145-refactoring-high-performance-java-cpu.md
- references/145-refactoring-high-performance-java-memory-allocation.md
Open the folder on GitHubat commit dca88dc
Compare with similar skills
145 Java Refactoring High Performance next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| 145 Java Refactoring High Performance this skilljabrena/plinth | 446 | — | ~937 | Automated safety check: Pass | Apache-2.0 | |
| Java Design Patterns Referencedecebals/claude-code-java | 751 | 1 repos | ~4.4k | Automated safety check: Pass | MIT | |
| Bootui Java Developmentjdubois/boot-ui | 307 | — | ~1.3k | Automated safety check: Pass | Apache-2.0 | |
| Goinference-gateway/inference-gateway | 214 | — | ~2.4k | Automated safety check: Pass | Apache-2.0 | |
| Java 21 Developer Guide for Grailsapache/grails-core | 2.9k | — | ~1.9k | Automated safety check: Pass | Apache-2.0 | |
| Spring Data Developmentarangodb/spring-data | 116 | — | ~620 | Automated safety check: Pass | Apache-2.0 |
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Questions about 145 Java Refactoring High Performance
What does 145 Java Refactoring High Performance do?
A skill your agent uses when you need to refactor Java code for high performance — including memory/allocation reduction, CPU hot-path optimization, and syntax/API/control-flow improvements. 145 Java Refactoring High Performance is an agent skill from jabrena/plinth. Use when you need to refactor Java code for high performance — including memory/allocation reduction, CPU hot-path optimization, and syntax/API/control-flow improvements.
When should I use 145 Java Refactoring High Performance?
145 Java Refactoring High Performance fits situations like: you need to refactor Java code for high performance — including memory/allocation reduction; CPU hot-path optimization; syntax/API/control-flow improvements; requests such as Review Java code for high performance.
How do I install 145 Java Refactoring High Performance in Claude Code?
Run `npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a claude-code`. Or copy the skill folder (skills/145-java-refactoring-high-performance in jabrena/plinth) into .claude/skills/145-java-refactoring-high-performance in your project. Claude Code loads it when a task matches its description.
How do I install 145 Java Refactoring High Performance in Codex?
Run `npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a codex`. Or copy the skill folder (skills/145-java-refactoring-high-performance in jabrena/plinth) into .agents/skills/145-java-refactoring-high-performance in your project. Codex loads it when a task matches its description.
Can I use 145 Java Refactoring High Performance in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add jabrena/plinth --skill 145-java-refactoring-high-performance -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/145-java-refactoring-high-performance, .gemini/skills/145-java-refactoring-high-performance, .github/skills/145-java-refactoring-high-performance and .opencode/skills/145-java-refactoring-high-performance in your project.
What does 145 Java Refactoring High Performance need to run?
SKILL.md names no scripts, command-line tools or credentials: 145 Java Refactoring High Performance is instructions for the agent only.
Does 145 Java Refactoring High Performance access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is 145 Java Refactoring High Performance safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does 145 Java Refactoring High Performance use?
145 Java Refactoring High Performance is published under the Apache-2.0 licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does 145 Java Refactoring High Performance use?
About 937 tokens (SKILL.md is roughly 3.7k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 16k tokens, read only when the agent opens those files.
What are the alternatives to 145 Java Refactoring High Performance?
Skills that share tags, products or a category with 145 Java Refactoring High Performance: Java Design Patterns Reference (decebals/claude-code-java, 751 stars), Bootui Java Development (jdubois/boot-ui, 307 stars), Go (inference-gateway/inference-gateway, 214 stars) and Java 21 Developer Guide for Grails (apache/grails-core, 2.9k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains 145 Java Refactoring High Performance?
jabrena (a GitHub user) maintains it in jabrena/plinth, which has 446 GitHub stars. The repository holds 124 skills in this directory. The repository was last updated on October 7, 2026.
Source: jabrena/plinth on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.