This article explains the role of Spring's MergedBeanDefinitionPostProcessor, showing how it merges bean definitions, invokes post‑processors during bean creation, and enables @Autowired‑related dependency injection with code examples and detailed workflow steps.
This article walks through creating a reusable Redis connection‑pool manager and a functional wrapper class in Java, explaining pooling concepts, resource recycling, and providing ready‑to‑use methods for common Redis commands to support efficient performance testing with the FunTester framework.
This article explains how Spring implements nine classic design patterns—including Simple Factory, Factory Method, Singleton, Adapter, Decorator, Proxy, Observer, Strategy, and Template Method—detailing their implementation mechanisms, core principles, key Spring interfaces, and code examples for each pattern.
This article explains how to avoid out‑of‑memory errors during massive data migrations by choosing appropriate Spring Batch readers, comparing JdbcCursorItemReader and JdbcPagingItemReader, and showing code examples and memory‑usage diagrams.
Linux kernel 5.14 has been promoted to stable, bringing extensive hardware support, core scheduler enhancements, new graphics drivers, expanded ARM and RISC‑V capabilities, and numerous updates for laptops, servers and peripherals, offering developers a richer, more secure platform for modern workloads.
This guide explains the purpose of Spring Boot's @Enable* annotations, how they rely on @Import, and walks through creating a custom @EnablePack annotation with accompanying configuration and usage in a Spring Boot application.
This guide demonstrates how to integrate RocketMQ 4.8.0 into a Spring Boot 2.3.9 application, covering dependency setup, configuration, sending and receiving plain, ordered, clustered, broadcast, and transactional messages, with complete code examples and execution results.
This article explains the history, recent updates, and step‑by‑step usage of the Spring Boot Swagger starter, including dependency setup, detailed configuration options, grouping, JSR‑303 validation support, custom response messages, UI tweaks, ignored parameter types, and authorization settings.
This article explains how to configure and inject List, Map, Set, and array values in Spring applications using @Value annotations, EL expression split functions, default values, and custom parsing methods, providing practical code examples and discussing the advantages and limitations of each approach.
This article explains how to implement efficient real-time WebSocket message pushing in a distributed system by using Redis as a coordination layer, defining Go-based Client and ClientManager components, and detailing the end‑to‑end flow from message production to client delivery.
This guide explains how WebSockets enable full‑duplex communication over a single TCP connection, compares popular Go WebSocket libraries, and provides complete client‑server code examples for TCP, UDP, and HTTP‑based WebSocket implementations, helping developers build real‑time applications such as chat, games, and monitoring tools.
This article explains how to build a simple PHP IoC container with reflection to automatically resolve constructor and method dependencies, demonstrates its use with example classes A, B, and C, and shows how to invoke methods with injected parameters.
The article presents a case study of Xianyu’s extensible user identity and benefits system, explaining how tiered identities grant differentiated product permissions and signal user influence, while detailing an authentication service with three extension points for condition judgment, validation, and audit handling, enabling flexible integration and unified state management.
This article examines the advantages and hidden risks of using Lombok in Java projects, illustrating how its annotations can dramatically reduce boilerplate code while also introducing version compatibility issues, forced dependencies, reduced readability, increased coupling, and technical debt, and suggests alternative approaches for cleaner code.
This article provides an in-depth overview of Java's Collections Framework, detailing the structure, usage, and source code of core interfaces like List, Set, Queue, and Map, and their key implementations such as ArrayList, LinkedList, HashSet, TreeSet, PriorityQueue, ArrayDeque, HashMap, and Hashtable, while highlighting performance characteristics and thread-safety considerations.
This article compares RabbitMQ and Kafka by explaining their architectures, queue consumption and production mechanisms, highlighting RabbitMQ's single‑master limitation and Kafka's partition‑based design for higher throughput, and provides guidance on selecting the appropriate middleware based on performance needs.
This guide explains how to lower the high memory usage of Spring Cloud applications on low‑end machines by adjusting per‑project JVM options in IntelliJ IDEA, detailing the necessary -Xmx, -Xms, -Xmn and -Xss parameters and showing the resulting performance improvement.
The article details the design and implementation of a dedicated pricing calculation engine that decouples complex e‑commerce promotion logic from transaction services, using componentized rules, configurable pipelines, multi‑level caching, and lane‑based simulations to achieve high extensibility, low latency, and accurate pricing across browsing and checkout scenarios.
This step‑by‑step tutorial explains how to create Restful file upload and download APIs using Spring Boot 2.2.6, covering environment setup, project structure, interface and implementation details, size‑limit configuration, global exception handling, and testing the endpoints with Postman.
This article explains the principles behind Linux's epoll mechanism, how IO multiplexing enables a single thread to manage many file descriptors efficiently, the role of non‑blocking sockets, and why epoll outperforms select and poll for high‑concurrency network services.
This article explains how Spring Boot's auto‑configuration works by loading configuration classes from spring.factories, using @EnableAutoConfiguration and conditional annotations to bind properties from application.properties or application.yml to beans such as ServerProperties, enabling rapid backend development without extensive manual setup.
Learn how to configure a Spring Boot 2.3.11 project with MyBatis 3.5.6, set up dependencies, pagination, mapper scanning, define mapper interfaces with annotations, implement dynamic SQL providers, and write comprehensive unit tests to verify CRUD operations.
The article details Vivo Mall’s new promotion pricing engine, which replaces duplicated site‑level logic with a layered model (product, shop, platform) that supports configurable stacking, processes discounts through three calculation stages, and uses a meta‑driven rule engine to flexibly interpret JSON promotion templates, ensuring extensible, stable pricing functionality.
This article walks through converting a Go‑based TCP private‑protocol server to support WebSocket on the same port, covering library selection, client and server implementation, request upgrading, and a complete usage example with code snippets.
The article presents a domain‑specific language that mimics Excel formulas, a stack‑based parser and recursive engine for evaluating calculations, and a multi‑layer architecture—including a dynamic priority scheduler—to efficiently resolve field dependencies, improve maintainability, and enable monitoring across large data systems.
This article explains the fundamentals of message queues, compares point-to-point and publish‑subscribe models, introduces Java Message Service (JMS) and its programming model, and provides an overview of popular MQ implementations such as RabbitMQ, ActiveMQ, RocketMQ, and Kafka, highlighting their architectures and use cases.
This article explains how Spring's @Autowired annotation works across constructors, methods, fields, arrays, collections, maps, optional dependencies, and special beans, providing practical code examples and important notes on required flags, ordering, and usage restrictions.
This article explains Spring's pointcut implementations, covering static and dynamic pointcuts, regular‑expression based pointcuts, the RegexpMethodPointcutAdvisor, control‑flow pointcuts, and how to create custom pointcuts by subclassing Spring’s abstract pointcut classes, with full XML and Java code examples.
This article examines the consistency challenges of using Redis as a cache, compares three update strategies—updating the database before the cache, deleting the cache before updating the database, and updating the database then deleting the cache—analyzes their pitfalls, and presents practical solutions such as delayed double‑delete, asynchronous retries, and binlog‑driven cache invalidation.
This article reviews various cache system types, compares popular distributed caches such as Memcache, Tair, and Redis, explains Redis cluster high‑availability mechanisms, discusses sharding strategies, and outlines common cache problems and solutions, providing practical configuration examples for Java backend developers.
This article explains cache consistency problems and solutions such as double‑delete and retry mechanisms, dives into Java fundamentals like HashMap internals and thread pools, and presents several backend interview coding questions with examples and code snippets.
After encountering duplicate order IDs during a system upgrade, the author analyzes the shortcomings of the original timestamp-and-random-based generator, demonstrates concurrency tests revealing collisions, and presents a revised Java implementation using atomic counters, shortened timestamps, and IP suffixes to reliably produce unique order numbers even under high load.
Spring MVC lets developers retrieve request data using the raw HttpServletRequest, or more conveniently with annotations such as @RequestParam, @RequestHeader, @RequestBody, and @CookieValue, supports automatic binding to POJOs including nested objects, injects native Servlet objects like HttpSession, and handles character encoding via CharacterEncodingFilter.
This article demonstrates how to use Fluent MyBatis, native MyBatis, and MyBatis‑Plus to query a student_score table for term‑wise statistics of English, Math, and Chinese scores, providing complete code examples, SQL statements, mapper definitions, and code‑generation configurations for each approach.
This article explains the avalanche effect caused by synchronous service calls, lists common scenarios, and demonstrates how to use Netflix Hystrix—through thread isolation, circuit breakers, and fallback methods—to protect backend services from cascading failures, complete with practical Java examples.
Midway 2.0 introduces a runtime‑based Hook system, removes compiler constraints, enables faster startup under 2 seconds, supports code reuse, new middleware models, flexible configuration via midway.config.ts, enhanced testing utilities, and broader deployment scenarios including web servers, all backed by open‑source Vite and Prisma integrations.
This article explains the three RabbitMQ exchange patterns—Direct, Fanout, and Topic—detailing how each routes messages, when to use them, and providing visual flowcharts to illustrate their operation in distributed backend systems applications.
This article explains how to use OpenResty with Lua to build a high‑performance caching layer that directly accesses Redis, compresses large responses, schedules periodic updates, forwards requests intelligently, and provides configurable URL caching, thereby improving concurrency, reducing latency, and optimizing bandwidth usage.
This interview explores the six‑year evolution of the dubbogo project, the motivations, challenges, and biggest contributions of PMC member Wongoo, and his vision for the future of this high‑quality Go implementation of the Dubbo RPC framework.
This article explains the inner workings of Spring Cloud's RefreshScope, covering its annotation definition, registration in the auto‑configuration, the refresh endpoint workflow, event handling, and how beans annotated with @ConfigurationProperties or @RefreshScope are dynamically refreshed at runtime.
This article explains the fundamentals of Domain‑Driven Design (DDD), outlines its strategic and tactical design processes, and demonstrates how Haro’s transaction platform applies DDD across taxi, e‑commerce, and core trading scenarios, highlighting benefits, challenges, and practical recommendations.
This guide demonstrates how to create a custom request‑handling method, register it programmatically with Spring MVC's RequestMappingHandlerMapping, and explains the underlying handler detection and mapping process in Spring Boot 2.2.
This article recounts the author’s experience building a simple Java web application for a university anniversary, covering planning, environment setup, documentation, database design, coding challenges with Spring Boot, Redis, and session handling, deployment on Alibaba Cloud, and the lessons learned about architecture, logging, and monitoring.
This comprehensive guide dives deep into Spring Validation, covering basic usage, dependency setup, requestBody and requestParam validation, group and nested validation, custom constraints, fail‑fast mode, and the underlying implementation in Spring MVC and AOP, all with practical code examples.
The article explains why multithreading is essential for modern CPUs, introduces thread pools to reduce overhead, and details Java's ThreadPoolExecutor creation parameters, execution process, and core methods such as addWorker, runWorker, and getTask, using JDK 1.8 source code examples.
This article presents a comprehensive guide to using Redis for various backend scenarios, including caching hot data, sharing sessions, implementing distributed locks, generating global IDs, counting, rate limiting, bitmap statistics, shopping carts, timelines, message queues, lotteries, likes, tags, product filtering, follow relationships, and ranking, all illustrated with concrete code examples.
This article explains how to fix KindEditor image upload errors caused by PHP's upload size restrictions by modifying the php.ini upload_max_filesize setting and increasing the $max_size value in KindEditor's upload_json.php file.
This article walks through the Spring Security authentication flow in a Spring Boot 2.2.11 application, detailing filter execution, token creation, provider selection, custom DaoAuthenticationProvider configuration, and session management, complemented by code snippets and diagrams for each step.
This article examines four major API architectural styles—RPC, SOAP, REST, and GraphQL—explaining how each works, outlining their advantages and disadvantages, and providing guidance on selecting the most suitable style for different project requirements.
This article outlines the ten most frequent errors developers make when using the Spring framework—ranging from over‑focusing on low‑level details to neglecting proper testing—and provides concrete best‑practice solutions with code examples to improve code quality, maintainability, and reliability.
This article explains how to use Spring Boot's @ControllerAdvice and @ExceptionHandler annotations to implement clean, global exception handling, covering basic usage, controller‑specific handlers, and ordered advice for multiple handlers, with practical code examples and diagrams.
This article introduces essential Java utility libraries—including built‑in methods, Apache Commons, and Google Guava—showing practical code snippets and Maven dependencies that help developers reduce boilerplate, improve readability, and boost productivity across backend projects.
The article explains Java’s automatic memory management, detailing JVM memory regions, object liveness via reachability analysis, allocation strategies, and the main garbage‑collection algorithms—Mark‑Sweep, Mark‑Copy, Mark‑Compact—and compares HotSpot collectors such as Serial, Parallel, CMS and G1, guiding developers to choose the best fit for their workloads.
This article outlines the objectives, detailed call flow, architectural design, and potential challenges of a unified payment center that consolidates order, payment, and financial services across multiple business lines, providing a secure, extensible, and data‑driven backend solution.
This article explains the design and architecture of a cloud-based shopping cart system, covering its functional modules, layered and cluster designs, distributed goals such as stability and elasticity, three-level caching, asynchronous checks, heterogeneous storage, payment solutions, and anti‑scalping measures.
This article outlines the career path toward software architecture, detailing the market expectations, essential competencies such as project management, technical depth, business insight, communication, decision‑making, and optimization techniques for systems, backend services, and databases, while emphasizing continuous learning and community involvement.
This article details the design and architecture of a cloud‑based shopping cart system, covering its functional modules, layered and cluster designs, technical goals such as stability and elasticity, three‑level caching, asynchronous checks, storage heterogeneity, and payment‑processing solutions.
This guide explains how to replace the old Alipay transfer interface with the new certificate‑based alipay.fund.trans.uni.transfer API, upgrade the SDK, configure certificates, add Maven dependencies, and implement Spring‑Boot beans and utility classes for secure payment and transfer operations.
HTTP/2, now widely supported by browsers and major sites, replaces HTTP/1.1 by introducing a binary framing layer, header compression, stream prioritization, server push, and flow control, addressing head-of-line blocking and inefficiencies while maintaining HTTP semantics, with detailed discussion of its evolution, structure, and deployment considerations.
Designing a flash‑sale (秒杀) system for massive concurrent users requires careful handling of instant traffic spikes, page staticization, CDN acceleration, caching strategies, distributed locks, rate limiting, asynchronous processing, and reliable stock management, with nine detailed techniques to ensure stability and prevent overselling.
This article explains four Spring‑Boot techniques—traditional AOP, HandlerInterceptor, HandlerMethodArgumentResolver, and Servlet Filter—to implement a reusable appkey whitelist validation, provides complete code examples for each, and clarifies their execution order within the request processing pipeline.
This article provides a comprehensive overview of Spring Batch, covering its purpose, architecture, core components such as Job, Step, ItemReader/Writer/Processor, execution contexts, chunk processing, skip strategies, and practical tips for configuration and memory management.
This article explains the AKF scalability cube for microservice architecture, detailing the Y‑axis functional decomposition, X‑axis horizontal scaling, Z‑axis data partitioning, as well as front‑end/back‑end separation, stateless services, and RESTful communication, providing practical diagrams and guidance for building robust, scalable systems.
This article explains the proxy design pattern, demonstrates its static implementation with Java code, and shows how Nacos Client leverages a custom proxy delegate to switch between HTTP and gRPC protocols, highlighting structural roles, practical usage, and differences from the decorator pattern.
This guide demonstrates how to configure and test various Spring Cloud Gateway filter factories—including AddRequestHeader, AddRequestParameter, AddResponseHeader, PrefixPath, StripPrefix, Retry, RedirectTo, and default filters—using Spring Boot 2.3.7 with Hoxton.SR9, complete with YAML snippets and code examples.
This article examines Lombok’s ability to shrink Java boilerplate, walks through code transformations from verbose getters and setters to concise annotations, and critically evaluates five major drawbacks—including JDK compatibility, forced adoption, readability loss, tighter coupling, and technical debt—offering guidance on when to avoid it.
This article explains the common points where messages can be lost in RabbitMQ and Kafka, compares transaction and confirm mechanisms, describes how to enable persistence and proper acknowledgments, and provides concrete configuration recommendations for producers and consumers to ensure reliable message delivery.
imageaffine is a PHP function that applies an affine transformation to a given image resource, optionally using a clipping rectangle, returning the transformed image on success or FALSE on failure, with detailed parameter specifications for the image, affine matrix, and clipping area.
This article explains the motivation, design principles, model architecture, and implementation challenges of rebuilding ByteDance's Node.js RPC system, covering DDD‑based decomposition, protocol and connection abstractions, multi‑protocol nesting, client/server creation APIs, and performance‑optimized context extensions.
This article presents a comprehensive collection of Baidu C++ engineers' performance‑optimization practices, covering memory‑access patterns, string handling, protobuf manipulation, allocator choices, job‑level memory arenas, cache‑line considerations, and memory‑order semantics to achieve substantial latency and cost reductions in large‑scale backend services.
This article walks through the evolution of an online supermarket from a simple monolithic website to a fully split micro‑service system, highlighting the motivations, architectural changes, operational challenges, and the tooling needed for monitoring, tracing, logging, and resilient deployment.
This tutorial explains how to use Elastic Job's sharding configuration in Spring Boot to accelerate scheduled task execution, improve resource utilization, and achieve high‑availability by distributing work across multiple job instances.
This guide explains how Spring's @Autowired annotation works across constructors, methods, fields, arrays, collections, maps, optional dependencies, and built‑in Spring components, providing code examples and tips for handling required and optional beans in a Spring 5.2.15 environment.
This article explains how Go’s lightweight goroutine model and user‑space scheduler provide faster, more efficient concurrency than traditional OS threads, detailing the design, execution environment, task queues, work‑stealing, and blocking mechanisms that make Go’s concurrency a standout feature for backend development.
The Fast App Center’s duplicate OpenID rows were traced to a non‑atomic check‑then‑insert race condition, prompting the team to evaluate a unique‑index safeguard versus application‑level distributed locking, ultimately implementing a Redis‑based lock to serialize inserts and adding a cleanup job to purge existing duplicates.
This article explains the overall architecture of a reactive API gateway built on RxNetty, detailing its request dispatch, conditional routing for gray releases, API management, rate‑limiting and circuit‑breaking, security policies, and integrated monitoring and tracing within a microservices ecosystem.
This article explains the purpose and inner workings of Spring's @Transactional annotation, detailing how AOP and dynamic proxies create transactional proxies, the role of BeanPostProcessor, advisors, TransactionInterceptor, and the transaction lifecycle, accompanied by code examples and diagrams for deeper insight.
This article explains how to abstract business functions into a middle platform through 0‑level and 1‑level modeling, defines domain capabilities and centers, outlines eight service design principles, and describes essential distributed mechanisms such as service registration, elastic scaling, rate limiting, gray release, messaging, and distributed transactions.
This article explains Spring's Service Provider Interface (SPI) mechanisms—including spring.handlers and spring.factories—covers their implementation details with code examples, demonstrates real‑world usage in MyBatis, Dubbo and Spring Boot, and shows how to create a custom configuration file loader.
This article explains the Chain of Responsibility design pattern, outlines its four roles, demonstrates a real‑world Java implementation for encrypted request handling, and shows how to build an extensible processing chain that improves code readability and maintainability.
This article explains the @Autowired annotation in Spring, covering its various usage forms such as constructor, setter, method, field, and collection injection, and delves into the underlying implementation details within Spring's AutowiredAnnotationBeanPostProcessor, including metadata handling, reflection-based injection, and common pitfalls.
This article demonstrates how to trigger and interpret JVM garbage‑collection logs by creating a small Java program, configuring heap parameters, and dissecting both young and full GC log entries to reveal causes, memory changes, and performance implications.
Knife4j is a lightweight, feature‑rich enhancement for Swagger that integrates seamlessly with Java MVC frameworks, offering customizable UI, advanced functionalities like interface sorting and export options, and easy Maven integration for both monolithic Spring Boot and Spring Cloud microservice architectures.
Node.js 16.5.0 introduces an experimental Web Streams API, updates core modules like fs, upgrades npm to 7.19.1, and adds numerous build improvements for better performance, scalability, and compatibility across platforms.
The PHP rewinddir function resets a directory stream resource opened by opendir() back to the beginning of the directory, returning the filename on success or FALSE on failure, and requires a valid directory handle as its sole parameter.
Provides a detailed explanation of PHP's readdir function, including its signature, parameters, return values, and example code demonstrating correct and incorrect ways to iterate through directory entries using a directory handle opened by opendir().
This tutorial explains how to create and configure scheduled tasks in Spring Boot, demonstrates code examples for simple 5‑second intervals, details the @Scheduled annotation parameters, and discusses the pitfalls of clustering without distributed locks.
This article explains how to use Redis's SCAN command to iterate over dictionary data, clean up stale keys, understand the command's underlying mechanics during dictionary resizing, and avoid common pitfalls through practical code examples and performance analysis.
This comprehensive guide walks you through Docker fundamentals, compares containers with virtual machines, explains core concepts, shows step‑by‑step installation, image building, container execution, and best practices, enabling you to containerize and deploy web applications efficiently.
The article explains Nginx’s high‑performance, event‑driven architecture, detailing its master‑worker process model, asynchronous non‑blocking I/O, CPU affinity, accept‑mutex load balancing, and the modular design built around ngx_module_t, covering core and HTTP modules, configuration parsing, data structures, and compilation guidelines for developers.
Spring GraphQL has officially left the experimental stage to become a top‑level Spring project, with a milestone release planned, and the article explains its collaboration with GraphQL Java, the goals of the integration, a brief overview of GraphQL versus REST, and upcoming conference talks.
The talk by Zha Jia showcases StreamNative’s open‑source Function Mesh, which builds on Apache Pulsar’s unified messaging and streaming platform and its lightweight Pulsar Functions, using Kubernetes CRDs to simplify deployment, management, and scaling of serverless data processing while highlighting the project’s rapid community growth.
Spring Cloud Alibaba 2.2.6, compatible with Spring Cloud Hoxton.SR9, introduces feature enhancements for Nacos, Dubbo, and Sentinel along with numerous bug fixes, providing developers with improved service registration, refactored integrations, and resolved issues across Kubernetes, Consul, and tracing components.
This guide walks through creating a lightweight service registration and discovery mechanism using Spring Boot 2.2.10, Zookeeper 3.6.2, and Java, covering environment setup, Maven dependencies, configuration files, core Java classes, and a test controller to verify dynamic service lists.
This article explains the drawbacks of traditional synchronous architectures, outlines why adopting message queues improves latency, coupling, and peak‑handling, and then details common MQ problems such as duplicate messages, data inconsistency, loss, ordering, backlog, and increased complexity along with concrete mitigation strategies.
This article explains the core differences between Java NIO and traditional IO, introduces channels and buffers, details NIO’s underlying mechanisms, provides a complete code example, and compares NIO’s workflow with Netty’s model, highlighting performance and architectural distinctions.
A recent JVM Ecosystem 2021 report reveals that over 60 % of developers have moved from Java 8 to Java 11 in production, surpassing Java 8 usage, while 40 % run multiple versions, highlighting a significant shift in Java version adoption.
This guide explains Spring Boot's two programmatic transaction approaches—TransactionTemplate/TransactionalOperator and direct TransactionManager—provides detailed code examples for using TransactionTemplate with return values, rollbacks, property configuration, demonstrates PlatformTransactionManager usage, and shows how to listen to transaction events with @TransactionalEventListener.
This article explores how backend developers can handle intricate e‑commerce search filters by first attempting a monolithic SQL solution, then improving performance with index analysis and query splitting, and finally achieving fast, scalable results using Redis sets, sorted sets, and transaction commands.
This article provides a detailed introduction to Zookeeper, covering its definition as a distributed coordination service, core features such as a hierarchical file system, notification mechanism, and cluster management, various application scenarios, the ZAB protocol, node types, leader election process, distributed lock implementation, and watch mechanism, all illustrated with diagrams.
