MCPInstall

java-fundamentals

by pluginagentmarketplaceBackend & APIs

Master core Java programming - syntax, OOP, collections, streams, and exception handling

Installs
619
Last 24h
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Install

Works with every agent the skills CLI supports.

npx skills add https://github.com/pluginagentmarketplace/custom-plugin-java --skill java-fundamentals
  1. 01

    Install

    Run the command in your project. The CLI asks which agents to install for.

  2. 02

    Describe the task

    Ask your agent for something this skill covers. It loads java-fundamentals automatically when relevant.

  3. 03

    Review the result

    The agent follows the SKILL.md steps, scripts and references bundled with the skill.

SKILL.md

The instructions your agent reads when the skill is triggered.

Java Fundamentals Skill

Master core Java programming with production-quality patterns.

Overview

This skill covers Java fundamentals including syntax, OOP, collections, streams API, and exception handling for Java 8-21.

When to Use This Skill

Use when you need to:

  • Write clean, idiomatic Java code
  • Design classes following OOP principles
  • Choose appropriate collection types
  • Implement functional programming patterns
  • Handle exceptions properly

Topics Covered

Core Syntax (Java 8-21)

  • Variables, data types, operators
  • Control flow, methods, classes
  • Records (Java 16+), sealed classes (Java 17+)
  • Pattern matching (Java 21)

Object-Oriented Programming

  • Classes, inheritance, polymorphism
  • Interfaces and abstract classes
  • SOLID principles

Collections Framework

  • List: ArrayList, LinkedList
  • Set: HashSet, TreeSet
  • Map: HashMap, ConcurrentHashMap
  • Queue: ArrayDeque, PriorityQueue

Streams API

  • filter, map, flatMap, reduce, collect
  • Optional handling
  • Parallel streams

Exception Handling

  • Checked vs unchecked exceptions
  • Try-with-resources
  • Custom exceptions

Quick Reference

// Record (Java 16+)
public record User(String name, String email) {}

// Pattern matching (Java 21)
String format(Object obj) {
    return switch (obj) {
        case Integer i -> "Int: %d".formatted(i);
        case String s -> "String: %s".formatted(s);
        default -> obj.toString();
    };
}

// Stream operations
List<String> names = users.stream()
    .filter(User::isActive)
    .map(User::getName)
    .sorted()
    .toList();

// Optional handling
String name = Optional.ofNullable(user)
    .map(User::getName)
    .orElse("Unknown");

Collection Selection

NeedUseReason
Indexed accessArrayListO(1) random access
Unique elementsHashSetO(1) contains
Sorted uniqueTreeSetO(log n) sorted
Key-value pairsHashMapO(1) get/put

Troubleshooting

ProblemCauseSolution
NullPointerExceptionNull referenceUse Optional
ConcurrentModificationExceptionModify during iterationIterator.remove()
ClassCastExceptionWrong typeUse generics

Usage

Skill("java-fundamentals")

FAQ

What does the java-fundamentals skill do?

Master core Java programming - syntax, OOP, collections, streams, and exception handling

How do I install java-fundamentals?

Run npx skills add https://github.com/pluginagentmarketplace/custom-plugin-java --skill java-fundamentals in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/java-fundamentals/ (personal) or .claude/skills/java-fundamentals/ (project).

Which AI agents can use java-fundamentals?

Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.

Is java-fundamentals safe to install?

No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.

Who maintains java-fundamentals?

It is published by pluginagentmarketplace in pluginagentmarketplace/custom-plugin-java. It has 619 recorded installs.

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