Programming

Интеграционные тесты в Java: ускоряем Testcontainers через tmpfs и прединициализацию

Testcontainers - Java-библиотека, которая управляет Docker-контейнерами прямо из тестового кода. Во время выполнения тестов она запускает нужный конте…

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…

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 …

[Перевод] Новые возможности Hibernate 7.4

Hibernate 7.4 исправляет старую проблему с пагинацией и fetch join. Раньше запрос на первые 10 Order вместе с OrderItem не мог безопасно ограничиться …

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…

8 вопросов с java-собеса в банке: Junior отвечает за 10 секунд, Senior — за 3 минуты. Кого берут?

Один вопрос на собесе — три ответа. «Что такое индекс?» спрашивают и джуна, и сеньора. Вопрос один — меняется глубина. По ней и считывают грейд. Разоб…

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 …

Pagination records using JooqTemplate

Paginated queries with automatic total count calculation. Supports specifying result fields. public < E > LimitResult < List < E >, E &…

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…

Simplifying Weak Reference Processing in ZGC

# Why Do We Use PasswordEncoder in Spring Security?

When I first started learning Spring Security, I had a simple question: "If Spring Security can authenticate users using usernames and passwords, why …

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…

Java Solution - LeetCode Problem 1 Two Sum

Problem Description: Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to the target. You…

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…

Mastering Encapsulation in Java

Introduction Object-Oriented Programming (OOP) is built on four core principles: Encapsulation Inheritance Polymorphism Abstraction In this article, w…

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…