15 years of IT industry experience, sharing practical insights on pre-sales, product design, architecture, technology development, software testing, project management, IT consulting, and operations management.
The article explains how Java source code is compiled into bytecode, how class loaders (including the bootstrap, extension, application, and custom loaders) load and verify classes using the parent‑delegation model, and how encryption, obfuscation, and decompilation tools affect code protection and debugging.
This article explains the five SOLID object‑oriented design principles with everyday Java scenarios, showing bad implementations, proper refactorings, practical criteria for each rule, and common pitfalls to help developers write more maintainable and extensible code.
The article enumerates typical problems encountered in application, database, cache, message‑queue, file‑server, and search clusters—such as session loss, uneven load, data inconsistency, and node failures—and provides concrete mitigation strategies like JWT authentication, distributed locks, health checks, NTP sync, and proper sharding.
This article explains the fundamentals of batch processing, outlines its non‑real‑time nature, lists typical scenarios and pros‑cons, provides practical implementation guidelines, and presents three detailed industry case studies illustrating how large‑scale offline jobs are built and maintained.
This guide breaks down nine budget ranges from 2,000 to 10,000 RMB, offering three pre‑configured desktop builds per tier—office, gaming, and productivity—complete with component lists, performance pros and cons, and practical selection tips for 2026 hardware.
The article explains how using plain HTTP instead of HTTPS exposes data to eavesdropping and tampering, illustrates real‑world attack scenarios such as MITM on public Wi‑Fi, and outlines step‑by‑step countermeasures including full‑site HTTPS deployment, forced redirects, HSTS, and additional payload encryption.
The article defines replay attacks, outlines high‑risk scenarios such as payment and coupon redemption, demonstrates two real‑world exploits, and presents four practical mitigation techniques—including unique transaction IDs, timestamp windows, one‑time nonces, and signature verification—to protect APIs.
The article explains how unsanitized user‑supplied filenames combined with simple path concatenation enable attackers to traverse directories and read arbitrary files, illustrates common vulnerable endpoints with Java examples, and outlines prioritized defenses such as ID whitelisting and canonical path validation.
The article defines file upload vulnerabilities, illustrates common attack scenarios such as front‑end bypass, suffix tricks, content‑type spoofing, image‑based payloads, and header manipulation, and provides a step‑by‑step secure implementation guide including backend‑only validation, whitelist checks, magic‑number verification, random renaming, isolated storage, size limits, filename sanitization, and optional virus scanning.
The article explains fundamental concepts of encryption and decryption, compares symmetric (AES, DES) and asymmetric (RSA, SM2) methods, describes hash functions (SHA256, MD5, SM3) and their proper use with salting, outlines hybrid RSA‑AES schemes, HTTPS workflow, and common pitfalls such as misuse of Base64.
