Sharing Java developer knowledge, practical articles, and continuous insights into computer engineering.
This tutorial shows how to use Javax Validator annotations to simplify backend service interfaces, covering basic, collection, date, enum, conditional, group, and custom validations with complete Maven dependencies and example code, plus handling of validation exceptions.
This article explains how to use Nginx to implement gray release—gradually rolling out a new application version to a subset of users—by configuring header‑based, cookie‑based, and IP‑address‑based routing strategies, detailing the required Nginx directives, deployment steps, and verification process.
This article explains the differences between Body and Params parameters in Spring Boot, covering various Content‑Type configurations such as query, x‑www‑form‑urlencoded, form‑data, binary, and JSON, and provides code examples and a clear comparison table to help developers choose the right approach for stable and efficient API design.
This article explains how to design and implement a reliable, resumable multipart file upload system in Java, using Redis for session tracking, FileChannel for zero‑copy merging, progress monitoring, checkpoint files for resume support, and NFS shared storage for Docker‑based distributed deployments.
This tutorial walks you through using Charles on macOS to capture and manipulate HTTP and HTTPS traffic for both PC and mobile devices, covering proxy configuration, SSL handling, breakpoints, throttling, DNS spoofing, request rewriting, remote/local redirection, and basic stress testing.
This article walks through the complete lifecycle of an HTTP API call initiated with Postman, covering DNS resolution, TCP/IP connection, Nginx reverse proxy and load balancing, Spring Boot request handling, service layer processing, JSON serialization, and the final response delivery back to Postman.
This article explains common encryption and signing algorithms—including AES, SM4, RSA2, and SM2—covers key representations in hex and Base64, details digital certificate structures, CSR application, TLS usage scenarios, OpenSSL commands for PEM conversion, and provides Java and JavaScript code examples for secure communication.
This article explains OpenSSL’s origins, its role in encryption on CentOS, common use cases such as web servers and database security, provides step‑by‑step installation and upgrade commands, and demonstrates how to generate RSA, SM2, AES, and SM4 keys via the OpenSSL command line and Java alternatives.
Web containers, such as Tomcat, keep running by continuously listening on network ports with socket servers and thread pools, handling I/O requests; this article explains the role of the main function, servlet lifecycle, Netty’s NIO framework, and why WebFlux‑based gateways outperform traditional Tomcat setups.
This article explains the key performance metrics TPS (transactions per second) and QPS (queries per second), provides formulas for calculating them, and demonstrates practical calculations for multi-node deployments, illustrating how request latency, thread pools, and instance count affect overall system concurrency and throughput.
