Dedicated to sharing advanced Java technical insights, daily work snippets, and the power of persistent effort.
This article explains how Spring AOP integrates AspectJ using CGLIB or JDK dynamic proxies, walks through a complete logging aspect example, and details the internal registration, proxy creation, and invocation processes that enable cross‑cutting concerns without modifying business code.
The article explains why regular ThreadLocal cannot share data from a parent thread to its child, introduces InheritableThreadLocal as a built‑in solution, shows its limitation with thread‑pool reuse, and demonstrates how Alibaba's TransmittableThreadLocal overcomes this issue with concrete code examples and output.
The article explains Java's ThreadLocal mechanism, detailing how each thread maintains its own ThreadLocalMap, provides practical code examples, examines the underlying source implementation—including set and get methods—and discusses potential memory‑leak pitfalls and ways to avoid them.
This guide explains how to add a unique traceId to each request in a Spring Boot application, configure Logback/MDC to record it, propagate the ID across microservice calls and asynchronous threads using OpenFeign, RestTemplate, and TransmittableThreadLocal, enabling complete distributed log tracing.
This article explains how Redisson extends Redis to provide a rich set of distributed Java objects and services, walks through integrating Redisson into a Spring Boot project, demonstrates various lock types (reentrant, read‑write, semaphore, latch) with code examples, and details the internal watchdog mechanism that guarantees atomic lock acquisition and automatic renewal.
The article explains how Spring Boot projects can adopt a standard JSON response structure using a generic ResponseVO class and achieve automatic wrapping and global exception handling through a custom @ResponseResultBody annotation combined with ResponseBodyAdvice and @ControllerAdvice, reducing repetitive code and improving robustness.
The article explains Spring's three‑level cache mechanism for resolving singleton circular bean dependencies, walks through bean lifecycle stages, compares field, setter and constructor injection, shows configuration to enable circular references, and details the internal code paths that expose early bean references.
The article details the background, design choices, compression code generation methods, database schema, high‑concurrency handling, and implementation of an enterprise‑grade short‑URL service that pre‑generates collision‑free codes to achieve high performance and secure redirection.
The article explains how to protect Spring Boot APIs from unauthorized data access by adding data‑level permission checks, encrypting request parameters with AES and RSA, signing requests with SHA1WithRSA, and encapsulating the logic in a reusable @ApiSecurity annotation and AOP aspect.
This article walks through every stage of a Spring Bean's lifecycle—including instantiation, property population, initialization callbacks, usage, and destruction—while providing concrete code examples, execution traces, and an analysis of the underlying Spring source methods.
