We share common IT technologies (Java, Web, SQL, etc.) and practical applications of emerging software development techniques. New articles are posted daily. Follow IT Xianyu to stay ahead in tech. The IT Xianyu series is being regularly updated.
This article explains how to identify slow SQL statements, analyze execution plans with EXPLAIN, use profiling and tracing tools, and apply specific optimization techniques such as index tuning, query rewriting, and alternative storage solutions across a range of real‑world cases.
This article provides a comprehensive guide to relational database design with MySQL, covering ER modeling, BCNF and 3NF normalization, storage engine selection, character set and data type choices, and index design principles, illustrated through a student‑course selection example.
This article explains how to evolve a simple single‑server web application into a highly available, horizontally and vertically scalable system for billions of users by covering DNS, vertical and horizontal scaling, load balancing, database replication, sharding, denormalization, SQL/NoSQL choices, stateless design, caching, CDN and global deployment.
This article explains how to globally handle LocalDate, LocalDateTime, and LocalTime parameters in Spring Boot 2.x by creating custom Converter beans, configuring Jackson's ObjectMapper, using @DateTimeFormat, ControllerAdvice, and understanding the underlying parameter resolution mechanisms to avoid common pitfalls such as lambda‑based converter registration failures.
This article compares traditional object creation with Spring’s dependency injection, demonstrating how injecting DAO beans via XML configuration decouples service and data layers, includes Java code examples, test results, and visual analogies of gear systems to illustrate reduced coupling.
This article explains how to add SpringBoot DevTools for hot deployment, integrate Lombok to simplify JavaBean code, and configure the Spring Configuration Processor for property metadata, providing step‑by‑step instructions, IDE settings, and Maven dependency snippets for a smoother development experience.
SPL is an open‑source structured data processing language that extends full SQL‑92 functionality to a wide range of data sources—including CSV, Excel, JSON, NoSQL and Hadoop—allowing developers to perform complex queries, multi‑step calculations, and mixed‑source analytics without a traditional relational database.
This article explains why a WeChat mini‑program’s share card lost its QR code due to incorrect assumptions about Object.keys ordering, dives into the ECMAScript specification and V8’s internal property storage, and shows how to modify wxml2canvas to correctly sort elements and avoid the bug.
This article explains how to prevent data loss in MySQL by enabling binlog in ROW format, performing full and incremental restores using mysqldump or XtraBackup, executing point‑in‑time recovery, restoring individual tables, skipping erroneous SQL statements, and using flashback tools such as binlog2sql and MyFlash.
This article demonstrates how to build an interactive Winter Olympics-themed 3D web page using Three.js and React, covering model loading, custom materials, lighting, particle effects, and camera controls, with detailed code snippets and explanations for each component.
