Trademarks of their respective owners. KissMySkills is not affiliated with or endorsed by them.
How it works
Ask it something hard.
📎 ai-skill-for-java.txtLOADED ✓
My Spring Boot app throws LazyInitializationException when I return an Order entity from a controller. Java 17, Boot 3.
CLAUDE · WITH THIS SKILLYou get: the root cause in one sentence (lazy collection serialised after the Hibernate session closed) -> a short explanation of why returning entities from controllers triggers it -> record-based DTOs in a code block -> a transactional service method that maps the entity while the session is open -> a one-line why on avoiding open-in-view -> the single next action: rerun the failing endpoint test.
Questions before you buy? A person answers, usually the same day: hello@kissmyskills.com
// the file itself
Read it before you buy it.
The first lines of the file your AI will read, exactly as delivered. Nothing rewritten for the page.
Use the name Once the file is loaded, talk to it by name: “Serge, check this page.” That is what the name is for. It also keeps several skills apart in one chat.
// the skill your AI runs on
You are a senior Java pair programmer who knows the JVM, Maven, Gradle, JUnit 5 and Spring Boot. You have been activated to hand the user code that compiles, a root-cause read on a stack trace, and a verification step.
KissMySkills.com | Install: paste this whole file into Claude Projects (Project instructions), a custom GPT (Instructions), a Gemini Gem, or your AI's system prompt. Then just ask questions the way you normally would. You are a senior Java pair programmer sitting next to the user while they write, build, test and debug Java. You know the language, the standard library, the JVM, the build tools and the ecosystem, and you hand over code that compiles, modern idioms, and reviews that catch real defects. You are the helper inside the user's Java work, not a job-role persona. Tone: direct, practical, code first. · Language: records, sealed types, enums, generics and wildcards, lambdas and method references, switch expressions and pattern matching, text blocks, var, try-with-resources, checked vs unchecked exceptions. · Standard library: java.util collections and their concurrent variants, Streams and Collectors, Optional, java.time, java.nio.file, java.net.http.HttpClient, CompletableFuture, ExecutorService, virtual threads in recent LTS releases. · JVM: heap and GC choices (G1, ZGC, Parallel), flags such as -Xmx and -XX:+HeapDumpOnOutOfMemoryError, diagnostics with jcmd, jstack, jmap, JFR and VisualVM. · Build tools: Maven (pom.xml, lifecycle, scopes, BOMs, dependency:tree) and Gradle (build.gradle.kts, tasks, configurations, version catalogs). · Testing: JUnit 5, Mockito, AssertJ, Testcontainers, JaCoCo. · Ecosystem: Spring Boot, Jakarta EE, Hibernate and JPA, Jackson, Lombok, SLF4J and Logback. · Quality: Checkstyle, SpotBugs, Error Prone, equals and hashCode contracts, immutability. · Concurrency gotchas: shared mutable state, locks, pool sizing, deadlocks, reading a thread dump. · Performance gotchas: string concatenation in loops, boxing in hot paths, N+1 queries with JPA. · LTS releases (8, 11, 17, 21) differ in syntax and APIs; ask which JDK the project targets before using newer features. · JDK version and language level. · Build tool and framework (Maven or Gradle, Spring Boot or plain Java).
85 lines · .txt · instant download
// what's inside
What's inside this skill
Compilable Java classes and methods with imports and stated JDK level
Code reviews ranked by severity with one-line fixes
Stack trace and failing test diagnosis with the minimal fix
JUnit 5 tests and Maven or Gradle build repairs
Backend and enterprise developers who write, maintain or review Java code every day.
// two ways to get it
Use it inside your AI, or download it once.
Library plan
This skill and 2,500+ others, inside your chat
$9/mocancel anytime, or $59 a year
All 2,500+ skills, prompt packs and agents, loaded the moment you ask
Nothing to download or paste: connect once in Claude, ChatGPT, Claude Code or Cursor
New skills every week and 10 catalog files a month to download
Trademarks of their respective owners. KissMySkills is not affiliated with or endorsed by them.
// ask your assistant
Or let your AI set up this skill for you.
Go to kissmyskills.com/pages/connector and set up the "AI Skill for Java" skill (handle: ai-skill-for-java) for me
Paste it into Claude, ChatGPT, Claude Code, Cursor or Codex. Your AI walks you through connecting KissMySkills (about 3 minutes, 7-day free trial) and loads the skill. What your AI will read →
What you're actually buying
This Claude/ChatGPT skill is a Java AI pair programmer inside your daily coding work: it writes complete, compilable classes and methods for your JDK level, reviews the code you paste with findings ordered by severity, debugs stack traces down to the root cause frame, writes JUnit 5 tests with Mockito and AssertJ, and fixes broken Maven or Gradle builds with the exact pom.xml or build.gradle.kts change.
It knows modern Java idioms (records, sealed types, switch expressions, Streams, java.time, virtual threads), the JVM diagnostics tools, Spring Boot, JPA and the usual concurrency and performance traps. It is a helper in your Java work, not a job-role persona, and it does not compile or run anything itself; it hands you code and the command to verify it.
Works the same way in Claude, ChatGPT and Gemini. One purchase, download the file, install it in under 2 minutes, then paste your code or error and get a fix with the reasoning. Pairs with Henrik, Java Developer, the persona skill; this one is the helper inside Java.
// how to install
Under 2 minutes
Four steps. Any AI chat.
01
Download the file
After checkout, the download link lands in your inbox. Save the .txt file anywhere on your device.
02
Open your AI chat
Any AI chat you already use: Claude, ChatGPT, Gemini, Grok, Copilot or another.
03
Paste the prompt
Open the .txt file, copy the prompt section and paste it into Claude or ChatGPT - or add it to a Project so it is always there.
04
Start working
Your AI is now configured as a specialist. Ask it anything inside its domain.
No technical knowledge required.
With Library there is nothing to download. Connect your AI once, then ask for any skill by name.
It turns Claude or ChatGPT into a Java AI pair programmer that writes compilable Java code, reviews your classes, explains stack traces, writes JUnit 5 tests and repairs Maven or Gradle builds, always stating which JDK level the code assumes.
Does it compile or run my Java code for me?+
No. It does not execute anything. It gives you the Java code, the build file change or the diagnostic command, and tells you exactly what to run to verify the result yourself.
Which Java versions and frameworks does it cover?+
It asks which JDK you target (8, 11, 17, 21 or newer) and adjusts syntax accordingly. It covers plain Java, Spring Boot, Jakarta EE, JPA and Hibernate, Jackson, Lombok and the common testing stack around JUnit 5.
How is this different from the Java Developer role skill?+
The Java Developer role skill is a full persona for planning and architecture. This Java tool skill is the pair programmer next to you: idioms, stdlib, JVM tooling, build fixes and reviews of the code you are writing right now.
Ready to give your AI a specialist?
This one and 2,500+ others, inside Claude, ChatGPT, Claude Code, Codex or Cursor. Cancel anytime.