Java Concurrency

pluginagentmarketplace/custom-plugin-java

Covers the full spectrum of Java concurrency from basic threads to Java 21's virtual threads, with solid coverage of executors, locks, and CompletableFuture patterns. The quick reference examples are practical, especially the virtual thread executor and CompletableFuture composition patterns you'll actually use in production. The thread pool sizing guidance is helpful, though real tuning always depends on your specific workload. Bonded to the advanced Java agent, so it can handle everything from debugging race conditions with jstack to configuring ThreadPoolExecutor rejection policies. If you're dealing with concurrent code beyond basic synchronized blocks, this will save you from the usual gotchas.

skills.sh installs: 467
GitHub stars: 42
last updated: Aug 21, 2026

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Install

$ npx -y skills add pluginagentmarketplace/custom-plugin-java --skill java-concurrency --agent claude-code

Installs into .claude/skills of the current project.

Files

Java Concurrency Skill

Master Java concurrency patterns for thread-safe applications.

Overview

This skill covers concurrency from basic threads to virtual threads (Java 21+), including thread pools, synchronization, and CompletableFuture.

When to Use This Skill

Use when you need to:

Write thread-safe code
Implement parallel processing
Use async programming patterns
Tune thread pools
Debug concurrency issues

Topics Covered

Thread Management

Thread lifecycle and states
Daemon vs user threads
Interrupt handling

Synchronization

synchronized, volatile
Lock interfaces (ReentrantLock)
Atomic operations

Executors

ThreadPoolExecutor configuration
ForkJoinPool
Virtual Threads (Java 21+)

CompletableFuture

Async execution
Chaining and composition
Exception handling

Quick Reference

// Virtual Threads (Java 21+)
try (var executor = Executors.newVirtualThreadPerTaskExecutor()) {
    IntStream.range(0, 10_000).forEach(i ->
        executor.submit(() -> processRequest(i)));
}

SKILL.md on GitHub