Dedicated to sharing advanced Java technical insights, daily work snippets, and the power of persistent effort.
This article explains the background, creation, and detailed parameters of Java's ThreadPoolExecutor, walks through its task execution flow, warns against using Executors factory methods, and provides practical formulas for setting core pool sizes based on CPU‑bound or I/O‑bound workloads.
The article introduces the open‑source Java utility library Hutool, compares it with Guava, lists its modules, shows how to install it via Maven, and provides concrete code examples for HTTP requests, random codes, date handling, string manipulation, number operations, map utilities, encryption, captcha generation, and data desensitization, demonstrating how it can reduce boiler‑plate and speed up development.
This article explains the callback pattern in Java, compares synchronous and asynchronous callbacks, shows how to implement them with interfaces, anonymous classes, and Lambda expressions, and demonstrates practical uses in Spring bean factories and data‑processing pipelines.
This article provides a comprehensive guide to Google Guava, covering its core modules such as collections, concurrency, string utilities, I/O, caching, event bus, functional programming, reflection, and best‑practice code examples that demonstrate how to simplify and strengthen Java development.
The article examines the long‑standing debate over using Long or BigDecimal to represent monetary amounts, presents ten community‑sourced approaches with visual illustrations, analyzes the underlying precision problem, and concludes with a recommendation favoring BigDecimal for accurate financial calculations.
This article explains the purpose and usage of Spring MVC’s HandlerMethodArgumentResolver and HandlerMethodReturnValueHandler extension points, demonstrates how to implement custom argument resolvers and return‑value handlers, discusses common pitfalls such as handler ordering, and shows how to replace the default processors to achieve unified request and response processing.
This article walks through Java Stream fundamentals, showing how to replace verbose loops with concise Stream pipelines, compares map and flatMap, explains intermediate and terminal operations such as filter, sorted, distinct, limit, peek, foreach, and collect, demonstrates parallel streams, highlights common pitfalls, and summarizes the advantages and disadvantages of using Stream APIs in everyday development.
The article explains the concepts of Redis cache penetration, cache breakdown, and cache avalanche, compares their causes, and provides practical mitigation techniques such as parameter validation, null‑key caching, Bloom filters, rate limiting, hot‑data pre‑warming, and multi‑level caching to protect database stability.
The article analyzes the challenges of keeping MySQL and Redis data consistent under high concurrency, compares four write‑order strategies, explains why they can cause stale cache data, and presents recommended solutions such as Cache‑Aside, distributed locks, message queues, and Canal‑based binlog syncing.
This article surveys eleven Java‑based delayed‑task solutions—including DelayQueue, Timer, ScheduledThreadPoolExecutor, RocketMQ, RabbitMQ, Redis key‑expiration, Redisson, Netty’s HashedWheelTimer, Hutool SystemTimer, Quartz, and a simple polling loop—providing code demos, implementation principles, and practical pros and cons for each approach.
