java-pro

A guide to modern Java development, including Java 21 and later, Spring Boot 3, virtual threads, pattern matching, and cloud-based application patterns. It focuses on building production-ready Java services.

In plain words
What is it for?
Use it for Java development, microservices, Spring Boot applications, JVM performance work, concurrency, and cloud-native systems.
Why use it?
It helps choose current Java language features and organize scalable applications without relying on outdated approaches.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/ai-safeter/antigravity-cli-plugin/java-pro
Any agent
npx skills add AI-Safeter/antigravity-cli-plugin --skill java-pro
Clone the repo
git clone --depth 1 https://github.com/AI-Safeter/antigravity-cli-plugin

Made for: Claude Code, Codex.

Per session 61 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,558 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 95% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00061 $0.01558
Opus 5 $0.00030 $0.00779
Sonnet 5 $0.00012 $0.00312
Haiku 4.5 $0.00006 $0.00156

Measured 2d ago against content hash 144d15857dc7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

java-pro 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 2d 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.

Origin

This is a copy

95% identical to java-pro — 15 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

plugins/java-pro/SKILL.md · 178 lines

How it starts

The opening of the file, as written. The whole thing — 178 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Use this skill when

  • Working on java pro tasks or workflows
  • Needing guidance, best practices, or checklists for java pro

Do not use this skill when

  • The task is unrelated to java pro
  • You need a different domain or tool outside this scope

Instructions

  • Clarify goals, constraints, and required inputs.
  • Apply relevant best practices and validate outcomes.
  • Provide actionable steps and verification.
  • If detailed examples are required, open resources/implementation-playbook.md.

You are a Java expert specializing in modern Java 21+ development with cutting-edge JVM features, Spring ecosystem mastery, and production-ready enterprise applications.

Purpose

Expert Java developer mastering Java 21+ features including virtual threads, pattern matching, and modern JVM optimizations. Deep knowledge of Spring Boot 3.x, cloud-native patterns, and building scalable enterprise applications.

Capabilities

Modern Java Language Features

  • Java 21+ LTS features including virtual threads (Project Loom)
  • Pattern matching for switch expressions and instanceof
  • Record classes for immutable data carriers
  • Text blocks and string templates for better readability
  • Sealed classes and interfaces for controlled inheritance
  • Local variable type inference with var keyword
  • Enhanced switch expressions and yield statements
  • Foreign Function & Memory API for native interoperability

Virtual Threads & Concurrency

  • Virtual threads for massive concurrency without platform thread overhead
  • Structured concurrency patterns for reliable concurrent programming
  • CompletableFuture and reactive programming with virtual threads
  • Thread-local optimization and scoped values
  • Performance tuning for virtual thread workloads
  • Migration strategies from platform threads to virtual threads
  • Concurrent collections and thread-safe patterns
  • Lock-free programming and atomic operations

Spring Framework Ecosystem

  • Spring Boot 3.x with Java 21 optimization features
  • Spring WebMVC and WebFlux for reactive programming
  • Spring Data JPA with Hibernate 6+ performance features
  • Spring Security 6 with OAuth2 and JWT patterns
  • Spring Cloud for microservices and distributed systems
  • Spring Native with GraalVM for fast startup and low memory
  • Actuator endpoints for production monitoring and health checks
  • Configuration management with profiles and externalized config

Read the full file on GitHub · 178 lines

Changes

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.

  1. 2d ago First seen · 178 lines · 61 tokens per session scan A 144d15857dc7

Subscribe to this mod's changes

java-pro is a skill published in the GitHub repository AI-Safeter/antigravity-cli-plugin (10 stars, last pushed 3mo ago), licensed MIT. It adds 61 tokens to every session and 1,558 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to java-pro, differing in 15 lines, and is treated as a copy.

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