Your First Java Application — Running Code End to End
You've installed Java. You've written your first "Hello World" class. Now comes the part that actually matters: turning that file into a running progr…
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Your circuit breaker stops at the service layer. Slow SQL needs one too.
Your circuit breaker stops at the service layer. Slow SQL needs one too. A single slow query can take down an entire service in seconds. This post sta…
Subsets II | Backtracking
leetcode.com Problem Statement Given an integer array nums that may contain duplicates, return all possible subsets (the power set). The solution must…
Comparable vs Comparator in Java
In Java, sorting is an important operation when working with collections such as ArrayList, LinkedList, and other data structures. For primitive data …
spring-batch-db-cluster-partitioning v2.0.1 — Security Patch
This is a quick heads-up: v2.0.1 of spring-batch-db-cluster-partitioning is out — a drop-in security patch with no API changes. 🔒 What's fixed Spring …
Recap — M0 Foundations
This module built one thing, from many angles: the container — the part of Spring that creates your objects, wires them together, and hands them out. …
Stop Fixing Broken Architecture: Auto-Enforce Package Boundaries with Cursor Composer and ArchUnit
Stop Fixing Broken Architecture: Auto-Enforce Package Boundaries with Cursor Composer and ArchUnit In 2026, we aren't writing boilerplate anymore; we …
Map in Java
What is Map in Java? A Map in Java is a part of the Collections Framework that stores data in the form of key-value pairs . Each key is unique. Values…
Stop Parsing Raw Stack Traces: Debugging Virtual Thread Deadlocks with JDK 26 JSON Thread Dumps
Stop Parsing Raw Stack Traces: Debugging Virtual Thread Deadlocks with JDK 26 JSON Thread Dumps If you are still running jstack or grepping through a …
Max Consecutive Ones
Problem Statement Given a binary array nums , return the maximum number of consecutive 1's present in the array. Example Input: nums = [1,1,0,1,1,1] O…
Building Resilient Multi-Agent Systems
Introduction AI agent systems are evolving rapidly. Today, we already see multi-agent architectures capable of solving complex problems by breaking th…
Securing Financial APIs in 2026: Implementing Global Request Interceptors and Automated Audit Trails in Spring Boot
With the recent surge in security vulnerabilities across the Spring ecosystem in the first half of 2026, relying on scattered security validation insi…
"Confluence Docs Lie. Tie Your Documentation to Code Instead."
Every team has that Confluence page. The one that was carefully written to explain what the service does, what the API looks like, what each DB column…
OAuth2 Login with JWT and Refresh Tokens in Spring Boot — The Setup You'll Rebuild Every Time
Most Spring Boot applications eventually need authentication. And many teams rebuild the same foundation every time. Add a login endpoint. Generate a …
Your Codename One App, Now A Native Mac App
Codename One has run on the desktop for a long time through the JavaSE target, which is the same engine that powers the simulator. What it did not hav…
System Prompt Leakage vs Prompt Injection in Spring Boot AI
System Prompt Leakage vs Prompt Injection Spring Boot AI You've wired up a Spring Boot service to an LLM, added a SystemMessage with confidential busi…
How I built a search engine
Hello all, I built a search engine from scratch in Java. In a previous course we were given it as a group project, but since I worked on just the docu…
Streaming 25 Million Excel Cells Through 7 MB of Memory
Streaming 25 Million Excel Cells Through 7 MB of Memory TL;DR: I built an export pipeline that streams 15M+ records as formatted Excel files inside ZI…
AI-агент для склада в Джеймикс. Часть 1
Это первая из двух статей про построение AI-агента внутри Джеймикс-приложения. Джеймикс (или Jmix , ex. CUBA ) - высокоуровневый фреймворк для разрабо…
MCP Java SDK – Build Model Context Protocol servers in Java
Hi HN, I built an open-source Java SDK for building Model Context Protocol servers: https://github.com/6000fish/mcp-java It is intended for Java devel…
How I Built a Prompt-to-Music AI Agent & Browser-Based Karaoke Separator with React & ONNX
Tags: react , webdev , onnx , audio Introduction Music generation, vocal separation, and intelligent arrangement have traditionally been server-side t…
Low-Level System Design (LLD) in Java: A Beginner's Guide
Introduction When preparing for software engineering interviews, many developers focus heavily on Data Structures and Algorithms. However, as you move…
Securing Your Spring Boot Architecture: A Pragmatic Approach with Clprolf
Introduction Spring Boot is an incredible framework. It gives developers immense freedom to build and scale applications quickly. However, in large te…
Stop Hiding SQL Behind Your ORM: jOOQ, JPA, and JDBC Under Production Load
Most persistence debates in Java are framed incorrectly. The question is not: Should we use JPA, jOOQ, or JDBC? The real question is: Is this part of …
I built a tool that generates API docs from your source code - no annotations, no server running, no Swagger config
Before I get into it, yes, I know FastAPI gives you /docs out of the box. Yes, I know Spring Boot has SpringDoc. That is exactly why I want to explain…
Craig Walls’ Spring AI in Action is out: 5-book giveaway + Spring AI discussion
Spring AI is the Spring project's response to the gap in solutions for integrating enterprise Java with generative artificial intelligence models like…
I built a Spring Boot + Angular + JWT Full Stack Starter Kit — here's what I learned
Why I built this Every time I started a new Java full stack project I was spending 2-3 days just on setup — JWT configuration, Spring Security, CORS, …
Deploying Spring Boot to AWS EC2 with Docker and GitHub Actions — The Repeatable Way
Deploying a Spring Boot application to AWS EC2 is straightforward once you've done it. Getting there the first time — and repeating the setup on your …
What is the Purpose of the @Autowired Annotation in Spring Boot?
Learn what the @Autowired annotation in Spring Boot is, how dependency injection works, practical examples, best practices, and common mistakes to avo…
OpenAPI, ORM, SVG and Lottie
This is the third follow-up to Friday's release post . Saturday's was about how you iterate; yesterday's was about new platform APIs in the core; toda…