Focused on Java interview questions and practical article sharing, covering algorithms, databases, Spring Boot, microservices, high concurrency, JVM, Docker containers, and ELK-related knowledge. Looking forward to progressing together with you.
This article explains the fundamental distinctions between routers and switches—including their OSI layers, addressing methods, forwarding mechanisms, broadcast domains, performance, and typical use cases—while providing interview‑focused insights, detailed operation principles, and common follow‑up questions.
Facebook originally used Git but switched to Mercurial around 2012 because its massive monolithic repository caused severe performance bottlenecks, especially during file stat operations, and Git’s maintainers were unwilling to improve scalability, leading the team to evaluate alternatives like Perforce before adopting Mercurial’s clearer architecture and collaborative community.
The article walks through building a Spring Boot 3.2 application with JDK 21 as a GraalVM native image, compares binary and jar deployments, benchmarks against Go and Rust implementations, and concludes that AOT‑processed native images dramatically reduce startup time and memory usage despite long compile times.
This article presents twelve practical MyBatis‑Plus techniques—including avoiding isNull checks, selecting specific fields, batch operations, EXISTS subqueries, safe ordering, LambdaQuery type safety, between clauses, index‑aware sorting, pagination limits, null‑handling, performance tracking, enum mapping, logical deletion, optimistic locking, and increment/decrement methods—to help developers write cleaner, faster, and more maintainable Java code.
If you need a cost‑free replacement for Navicat, this article compares three MySQL client tools—DBeaver, MySQL Workbench, and HeidiSQL—detailing their installation steps, supported databases, key features such as monitoring and ER diagrams, and practical usage tips.
The article explains why concurrent Excel exports can overload a Java backend, describes a FIFO queue with a fixed capacity to serialize export tasks, shows the full implementation with Spring, EasyExcel and synchronized wait/notify, and discusses test results and remaining limitations.
This article breaks down the QR code login process used by Douyin, explaining how the system identifies the user, proves their identity through a token‑based authentication flow, and details each step from QR generation to final confirmation on the PC side.
The article explains two ways to implement a 30‑minute order auto‑cancellation in RabbitMQ—using the classic TTL + dead‑letter exchange pattern (with its head‑blocking pitfall) and the newer delayed‑message‑exchange plugin—provides Spring Boot configuration examples, compares their trade‑offs, and offers interview tips on when to choose each solution.
The article explains the fundamental design flaws of java.util.Date, why a code‑scan rule forces its removal, and provides a step‑by‑step guide to replace Date and related utilities with the modern java.time API, including concrete code transformations and migration tips.
RabbitMQ achieves consumer‑side throttling by configuring basic.qos with a prefetchCount, disabling automatic ACK, and using manual ACK so that the broker only pushes a limited number of unacknowledged messages, with detailed guidance on parameter settings, pitfalls, and code examples.
