This article explains how the PHP getcwd() function retrieves the absolute path of the current working directory, demonstrates usage with example code, discusses changing directories with chdir(), and highlights important considerations such as false returns and server‑side path differences.
This article presents the design concepts, transaction flow, core components, and practical experience of building a scalable e‑commerce payment architecture, illustrated with detailed diagrams of transaction sequencing, system modules, and operational considerations for high‑traffic sales events.
This article explains Nginx's regular‑expression support, the various location directive prefixes, their matching priorities, and provides concrete configuration examples with code snippets and diagrams to help you correctly route requests in a single‑node Nginx 1.23.2 setup.
This article shares ten frequent mistakes PHP developers encounter when switching to Go, covering function syntax, map initialization, JSON marshaling, loop variable handling, array vs slice semantics, and variable declaration nuances, each with problem description and corrected code examples.
The article examines a cache‑consistency failure in Tmall International’s high‑concurrency push system, explains classic cache problems and mitigation techniques, analyzes the delete‑then‑update bug that caused null‑plan errors, and evaluates four corrective strategies ranging from double‑write to delayed double‑delete.
This article presents a comprehensive collection of Spring Boot best practices—including package structuring, design patterns, starter usage, dependency management, constructor injection, SLF4J logging, pagination, caching, exception handling, naming conventions, and code quality tools—to help developers build more efficient, maintainable, and robust Java backend applications.
This article explains the PHP array_reverse() function, its syntax, optional preserve_keys parameter, and provides multiple code examples demonstrating how to reverse indexed and associative arrays and combine the function with sort() for more complex array manipulations.
This article provides an in‑depth explanation of the Spring Boot startup process, enumerates the key extension points, demonstrates their execution order with sample code and logs, and offers practical recommendations for correctly initializing RPC, MQ, and HTTP traffic.
This article introduces the concepts and core principles of RESTful APIs and provides a step‑by‑step Python Flask tutorial, including environment setup, code examples for CRUD operations, and guidance on testing, authentication, error handling, and versioning.
This guide examines ten popular distributed ID generation techniques—from simple UUIDs and database auto‑increment keys to advanced Snowflake, Redis, Zookeeper, and open‑source solutions like Baidu uid‑generator, Meituan Leaf, and Didi Tinyid—highlighting their pros, cons, and suitable scenarios for high‑traffic systems.
This article explains why a backend team moved from PHP to Go for high‑concurrency live‑streaming services, compares serial PHP processing with parallel Go execution, and demonstrates two practical Go concurrency patterns—sync.WaitGroup and errgroup—with complete code examples.
This guide explains how to customize the Spring Boot startup banner by creating a banner.txt file, using ANSI color codes, retrieving various Spring Boot properties, and optionally disabling the banner altogether through code changes.
This article explains the PHP basename() function, its syntax, parameters, and demonstrates its usage through multiple examples showing how to extract file names from absolute and relative paths and optionally remove suffixes.
This article explains why the Spring MVC @RequestBody annotation cannot be applied to multiple parameters in a single handler method, detailing the internal request‑body reading process, the resulting HttpMessageNotReadableException, and how to correctly handle multiple data parts using a single DTO.
This article demonstrates how to apply Google’s Wire tool in a production‑grade Go web service, covering project layout, a four‑layer architecture, code generation for constructors, comparisons with dig and inject, and practical CLI usage to streamline dependency injection and improve development efficiency.
This guide explains how to create an Enterprise WeChat application, obtain the required corp ID and secret, and use a Python script to send notification messages via the WeChat API, complete with code examples and expected results.
This article analyzes a FastJSON serialization issue where a newly added log line triggered unexpected method calls, explains the underlying ASM‑generated serializer and JavaBeanSerializer logic, demonstrates code examples, outlines common pitfalls such as @JSONField annotations and getter patterns, and proposes best‑practice conventions for reliable backend serialization.
This article explains PHP's rewind() function, detailing its syntax, parameters, return values, and providing two practical code examples that demonstrate resetting a file pointer for both reading and writing operations within a.
This article explains why parameter validation is essential in Java web development, compares traditional manual checks with validator libraries, demonstrates practical usage of Bean Validation, Hibernate‑Validator, and Spring Boot starter‑validation, and covers advanced topics such as nested validation, group validation, custom constraints, and the underlying validation mechanism.
This tutorial demonstrates nine practical ways to handle SpringBoot 3.2.5 request data, including Optional‑wrapped parameters, direct Servlet API access, retrieving the authenticated Principal, extracting method and locale, reading InputStream, using HttpEntity for headers and body, building request URIs, handling multipart parts, and passing flash attributes on redirects.
This article examines four common WeChat red packet distribution algorithms—simple random, double‑mean, line‑segment division, and array_rand optimization—explaining their principles, PHP implementations, performance characteristics, and how to verify randomness, providing code samples and comparative analysis for developers.
The article explains how to analyze, decompose, and design a complex payment workflow by breaking it into modules, defining pre‑payment, payment‑gateway, and post‑payment sequences, and outlining the essential data structures such as account management, transaction records, and order handling, while also highlighting practical implementation considerations.
This article explains the PHP ftell() function, detailing its purpose, parameters, return values, and providing a complete code example that reads the first ten bytes of a file, displays the content, and shows how to obtain and output the file pointer's byte offset.
This article explains how PHP's json_decode function can transform JSON-formatted strings into PHP objects or associative arrays, demonstrates usage with code examples, and shows the resulting output for both object and array conversions.
The article explains common pitfalls in Java API design—such as inconsistent return formats, missing error handling, irrelevant parameters, and improper use of maps or JSON strings—and demonstrates how adopting a unified ResultBean structure together with AOP can improve readability, error management, and testability of backend services.
The article examines a large-scale supply‑chain system’s architecture, highlighting issues with service placement and dependencies, proposing an intermediate API layer for aggregation, distributed calls, and decoration, and ultimately recommending a Backend‑for‑Frontend approach to tailor APIs per client while reducing coupling.
This article explains how to design a MySQL table for product sales statistics, initialize massive test data, and compare several query strategies—including loop queries, OR‑concatenated dynamic SQL, mixed filtering, and the SQL‑92 row‑comparison technique—to efficiently retrieve sales figures for multiple business units and their products without violating development constraints.
The article shows how to implement a hot‑plug AOP system in Spring that lets users enable or disable logging at runtime by scanning, registering, and deregistering Advice/Advisor/Pointcut beans through the bean factory, demonstrated with a REST endpoint that adds or removes a logging interceptor.
This article explains how the PHP cURL library, especially the curl_exec() function, can be used to initialize a session, set options, execute HTTP requests, handle errors, and retrieve remote page content efficiently.
This guide explains Laravel's exception handling system, covering the core Handler class, custom exception creation, HTTP error aborts, database query exception management, validation error handling, and logging techniques with practical code examples.
This article walks Java developers through the most useful JDK 17 enhancements—including text blocks, improved NullPointerException messages, records, the new switch expression, private interface methods, pattern matching, collection factory methods, enriched String APIs, Stream API upgrades, the modern HttpClient, JShell, direct file execution, and ZGC—showing code examples and practical benefits.
This guide details the workflow system’s underlying frameworks, functional modules, process design operations, form customization, deployment procedures, and task management features, providing a comprehensive overview for developers and administrators to effectively implement and maintain business processes.
The article explains a bug in Java's ConcurrentHashMap.computeIfAbsent that can cause recursive updates and infinite loops, leading to CPU spikes, and shows that newer Java versions throw an IllegalStateException while recommending avoiding nested computeIfAbsent/putIfAbsent calls, with a code example.
This tutorial explains Spring's core.convert package, introduces the Formatter interface, and provides step‑by‑step examples of creating custom formatters and annotation‑based formatters in Spring Boot, including code snippets, registration, and test endpoints with output screenshots.
This guide explains RabbitMQ's core concepts, architecture, installation via 1Panel, configuration of the Webman RabbitMQ plugin, and demonstrates how to set up producers and consumers with code examples for reliable message handling.
This article demonstrates three approaches for invoking external services in Spring Boot applications—using raw HttpClient, the RestTemplate utility, and Feign clients—providing code samples, configuration steps, and tips for handling headers and tokens.
This article explains the evolution from HTTP/1.1 to HTTP/3, detailing QUIC's UDP‑based design, its impact on connection establishment, migration, head‑of‑line blocking, multiplexing, congestion control, forward error correction, and flow‑control mechanisms for modern web services.
This article explains how to correctly use PHP's session_start function to initiate sessions, manage session data with $_SESSION, control session lifetime via session_set_cookie_params, and properly destroy sessions using session_destroy, providing clear code examples for each step.
This tutorial explains how to use PHP's LDAP functions to connect to an LDAP server, bind with credentials, and authenticate users by searching the directory and verifying passwords, providing complete code examples for each step.
This article demonstrates how Python metaclasses can be leveraged to automatically add authentication headers, manage configuration, log requests, handle exceptions, generate test cases, switch environments, validate parameters, control API versioning, register response validators, and inject dependencies, streamlining backend development.
The article explains how Fast‑Retry, an asynchronous multi‑task retry framework, dramatically outperforms synchronous retry libraries like Spring‑Retry and Guava‑Retry when handling massive workloads, and provides step‑by‑step code examples, performance benchmarks, and integration tips for Java developers.
This article explains the importance of URL encoding for transmitting special and non-ASCII characters, demonstrates how to use PHP’s urlencode (and rawurlencode) function with example code for English and Chinese strings, and discusses practical considerations such as handling spaces in GET requests.
Tencent News upgraded its recommendation architecture by consolidating data platforms, redesigning index and feature services, adopting DDD and Lambda/Kappa patterns, and adding robust debugging and stability measures, which boosted availability to 99.99%, cut CPU, memory and cost by over 60%, and accelerated development and experiment cycles.
This article explains PHP’s built‑in is_float() function, demonstrating how it checks whether a variable is a floating‑point number, with simple and complex code examples, output explanations, and notes on type strictness and practical usage scenarios.
A daily million‑order e‑commerce platform only generates about 30 TPS, making inventory‑deduction and oversell concerns trivial and solvable with a single atomic SQL update rather than complex distributed solutions.
This article explains the concept, use cases, and common implementations of delay queues—including JDK's DelayQueue, RabbitMQ plugins, and Redis ZSet—followed by a detailed guide to installing, configuring, and using the open‑source lmstfy project, and concludes with promotional information for ChatGPT‑related services.
This article explains the fundamentals of finite state machines, introduces Spring Statemachine, demonstrates how to model order lifecycle states, configure persistence with memory and Redis, handle exceptions during state transitions, and use AOP to log transition results, providing complete Java code examples.
This tutorial explains how to set up a simple yet powerful Java logging solution by installing Loki and Grafana via Docker, configuring Loki4j in a Spring Boot project, and visualizing logs in Grafana, providing step‑by‑step instructions and sample code.
This article explains PHP's fopen() function, detailing its syntax, parameters, and four practical code examples for reading, writing, appending, and accessing URLs, while emphasizing proper mode selection and the importance of closing file handles to release resources.
This article demonstrates how to use the junixsocket library to add Unix domain socket support to Java applications, providing Maven dependency details, full server and client code examples, and cross‑language testing with a Go server implementation.
This article explains how to create a custom annotation and MyBatis‑Plus interceptor that automatically injects data‑permission WHERE clauses based on the current user's role, covering both a basic implementation and an advanced version with role‑based scope handling, complete with configuration and usage examples.
This article recounts the technical and organizational challenges of building Tencent WeSee's 2020 Spring video red‑packet system, detailing high‑traffic spikes, consistency and security demands, TRPC adoption risks, performance bottlenecks, and the 33 robustness principles that guided the subsequent architecture overhaul.
A senior developer recounts how a Fortune‑500 project's ill‑planned outsourcing to a vendor using a massive MongoDB JSON store led to performance bottlenecks, hidden limits, and a frantic internal rewrite that forced the team to work through holidays and ultimately deliver a successful release.
This article explains how to implement a configuration‑driven mechanism that dynamically switches between Spring's native @Scheduled tasks and XXL‑JOB execution, automatically registers jobs, disables Spring's scheduler when needed, and forwards logs to the XXL‑JOB console, providing a complete starter solution for backend developers.
This article explains the PHP readfile() function, its syntax and return values, and provides step‑by‑step examples showing how to display a text file in the browser, force a download, and copy its contents to another file using simple PHP code.
This article explains the PHP explode() function, covering its syntax, parameters, and three practical examples that demonstrate splitting strings by spaces, commas with a limit, and empty strings to produce arrays.
This article explains the roles of DTO, VO, and PO in Java applications, compares manual property copying with BeanUtils and MapStruct, provides complete code examples for both approaches, and offers guidance on choosing the appropriate method based on performance and project needs.
This article explains PHP’s built‑in `floatval` function, showing its syntax, how it converts various variable types—including integers, strings, booleans, and arrays—to floating‑point numbers, and highlights important considerations such as handling non‑numeric strings that result in a zero value.
This article explains how to design a unified business error‑code system for RESTful APIs, demonstrates the structure and format of such codes, provides a Go implementation with structs, interfaces and formatting methods, and shows practical usage in a Gin web server including logging and notification strategies.
This article explains the concepts and step-by-step implementation of dynamically loading JAR packages in Spring Boot applications, covering built‑in classloader usage, creating JARs, and leveraging third‑party libraries to enhance flexibility and extensibility.
This tutorial walks through installing Portainer, using it to deploy a Redis master‑slave‑sentinel cluster with Docker Compose, creating a custom bridge network, testing failover, and finally integrating the sentinel setup into a Spring Boot application with Lettuce connection pooling and sample controller code.
This article explains how to use a Trie data structure in Go to efficiently store API paths with associated permissions, insert paths, perform fast permission validation, and demonstrates the approach with a complete, runnable code example and sample test cases.
This article introduces PHP's file_exists function, explains its boolean return value, shows how to check both local and remote files with code examples, and highlights important considerations such as correct paths, permissions, and potential HTTP overhead.
Java developers constantly battle NullPointerExceptions, a historic flaw introduced by Tony Hoare, but modern JDKs provide clearer messages and defensive techniques—such as explicit null checks, utility methods, avoiding null returns, and using Optional—can dramatically reduce these runtime errors.
This article details how ICBU's core communication pages were accelerated by applying HTTP chunked transfer, streaming HTML rendering, Nginx tweaks, ThreadLocal handling, and caching strategies, resulting in FCP dropping from 2.6 s to 1.9 s and LCP from 2.8 s to 2 s.
This article explains PHP's array_flip() function, showing its syntax, behavior with duplicate values, and practical examples that demonstrate how to exchange array keys and values for tasks such as reverse lookups and data manipulation.
This article explains how to use PHP's GMP extension to perform fast multiplication of large integers by applying a divide‑and‑conquer algorithm, reducing the complexity from quadratic to near‑linear, and provides a complete PHP implementation with example code.
This article explains how PHP’s built‑in array_pop function removes and returns the last element of an array, demonstrates its syntax, provides a complete code example that pops a fruit from a list, and shows the resulting output and remaining array contents.
This article explains three common multi‑tenant implementation strategies—separate databases, separate schemas, and partitioned (discriminator) data—detailing their advantages, drawbacks, and practical Spring Boot 3.3 code examples for entity definition, tenant‑ID resolution, data source routing, and request interception to achieve secure, scalable SaaS applications.
This article explains how to apply Dependency Injection in the Go Gin framework to separate routing logic from business services, reducing code coupling, improving testability, and enhancing reusability through concrete interface definitions, a simple DI container, and practical code examples.
The article recounts a Tencent engineer's six‑year journey from early DNS‑bypass tricks to modern HTTP/2 + QUIC implementations, highlighting technical challenges, security innovations, and the iterative process behind multiple promotion evaluations.
This article explains why rate limiting is essential in high‑traffic microservice architectures, illustrates the avalanche effect, and introduces five practical algorithms—including counter, sliding window, leaky bucket, token bucket, and Redis‑based implementations—complete with code examples and usage scenarios.
This article explains why upgrading to JDK 17 and switching to the low‑latency ZGC garbage collector can dramatically reduce pause times and improve throughput, compares GC and CPU metrics against G1, and provides step‑by‑step installation and JVM tuning instructions with code examples.
This article explains why Java logging can become a performance bottleneck, identifies common misuse patterns, and provides practical steps—such as dynamic log levels, avoiding string concatenation, selective location info, and cautious async logging—to dramatically improve throughput and latency.
AREX is an open‑source traffic recording and replay platform created by Ctrip that enables comprehensive testing—from performance and regression to rapid issue fixing—by capturing real traffic across complex micro‑service environments, addressing challenges such as async context, non‑idempotent calls, authentication, time‑sensitivity, and cache consistency, and offering easy CI/CD integration and large‑scale deployment.
This tutorial explains how to combine Node.js with OpenAI's AIGC to build a backend service that reads user comments, sends them to a GPT‑3.5‑turbo model for sentiment classification, and outputs whether the sentiment is positive or negative, complete with setup steps and full source code.
The article explains why front‑back end separation is needed, outlines common collaboration patterns, presents a staged migration from MVC to SPA, and provides detailed API request/response standards, interface versioning, and practical steps for implementing clean separation in modern web projects.
This article explains how PHP's built‑in intval() function converts different variable types—including strings, floating‑point numbers, and values in other bases—into integers, illustrating usage with code examples and noting that failed conversions return zero.
This article details how to create a Teamfight Tactics assistant bot on the Coze low‑code AI platform, covering background motivation, Coze features, workflow design, Node.js plugin development, API implementation, scheduled data clearing, and future improvement plans.
This article explains how to use PHP's curl_setopt_array() function to batch‑set cURL options, improving code readability and maintainability, and provides a complete example with code demonstrating initialization, option configuration, request execution, and response handling.
This article explains what a service gateway is, why it is essential for microservice architectures, outlines its core functions such as routing, filtering, authentication, monitoring, and presents a practical Java‑based technical stack including Spring Boot, Zuul, Consul, JWT, Prometheus, ELK and JMeter.
This article explains how to replace the default embedded Tomcat container in Spring Boot with Undertow, outlines the configuration steps, compares their performance and memory usage through benchmark results, and concludes that Undertow offers superior throughput for high‑concurrency Java web applications.
This article explains PHP's built-in floatval() function, its syntax, and provides multiple code examples showing how to convert integers, strings, booleans, and arrays to floating-point numbers, while also noting its behavior when conversion is not possible.
This article explains how to build a reusable Spring Boot starter that automatically encrypts outgoing responses and decrypts incoming requests using hutool‑crypto, custom request wrappers, validation utilities, and Spring Boot advice components, providing a secure, zero‑boilerplate solution for Java backend services.
This article explains common causes of Java OutOfMemoryError, demonstrates how to reproduce OOM with sample code, and provides step‑by‑step techniques using jmap, heap dumps, and VisualVM to locate and avoid memory leaks in backend applications.
This guide explains why validating configuration properties in SpringBoot 2.7 is essential, outlines the benefits such as increased robustness and faster debugging, and provides a step‑by‑step example with code snippets showing how to use @ConfigurationProperties, @Validated, and BeanPostProcessor for automatic validation at application startup.
This article explains how to connect to a MySQL database with PHP, execute a SELECT query, and use the mysqli_fetch_assoc function to fetch rows as associative arrays, including code examples and best‑practice notes for handling multiple rows.
This article provides a comprehensive guide to standardizing the Spring Boot controller layer by explaining how to receive parameters, define unified status codes, apply validation annotations, wrap responses consistently, and handle exceptions globally, all illustrated with practical Java code examples.
Reflecting on his 2023 technical writings, the author—prompted by the TV series 'Reply 1988'—structures his insights into chapters covering Domain‑Driven Design lessons illustrated by a Forrest Gump metaphor, business‑architecture note‑taking, judgment models drawn from everyday driving, and personal projects like the VSEF framework and the “曲径通幽” series, emphasizing curiosity, knowledge sharing, and continual growth.
The article explains several common reasons why Redis may degrade performance—such as network latency, misuse of high‑complexity commands, the KEYS command, clustered key expirations, and big‑key operations—and provides practical mitigation techniques like batch commands, TTL randomization, and lazy deletion.
This article introduces three request‑collapsing techniques—Hystrix Collapser, a custom BatchCollapser implementation, and Guava's ConcurrentHashMultiset—explaining their design, configuration, code examples, and suitable scenarios for reducing downstream load and improving system throughput.
This article explains how zero‑copy technology eliminates redundant memory copies and context switches during data transmission, compares traditional read‑send workflows with zero‑copy approaches such as Linux sendfile/splice and Java's FileChannel.transferTo, and discusses performance benefits and practical considerations.
This article provides a comprehensive set of Netty interview questions and detailed answers covering its architecture, Reactor pattern, core components such as Channel, ChannelHandler, ChannelPipeline, ByteBuf advantages, EventLoop groups, codecs, handling of packet framing, and graceful shutdown procedures.
This article explains the fundamentals of role‑based access control (RBAC), its model variants, and user‑group usage, then demonstrates how to configure Spring Security with in‑memory authentication, integrate JWT for stateless token‑based authentication, customize JSON login, and securely encrypt passwords using BCrypt.
This guide explains how to replace slow synchronous HTTP calls with Guzzle's asynchronous requests in PHP, showing code examples, performance measurements, and practical tips for installing and using promises to achieve faster concurrent API calls.
This article explains the fundamentals of caching, enumerates various client‑side, server‑side and distributed cache types, describes common caching patterns and expiration policies, and highlights practical considerations to effectively improve web application performance and reliability.
This article combines a narrative about a new Java developer’s struggle to master Git with a detailed tutorial covering Git’s definition, core concepts, typical workflow, and a comprehensive list of essential commands, highlighting its importance for effective software development.
This article explains the business value, architecture, configuration, storage design, performance challenges, and future plans of Bilibili's live streaming ranking system, detailing how rankings are generated, stored in MySQL and Redis, and updated through automated and manual scoring pipelines.
This guide explains how Spring's @Qualifier annotation eliminates bean injection ambiguities, shows basic usage, custom qualifier creation, generic qualifiers, fully custom annotations, and advanced attribute‑based qualifiers, all illustrated with clear Java code examples for Spring 6.1.2.
This article explains PHP's array_search() function, detailing its purpose, prototype, parameters, return values, and provides clear code examples demonstrating how to locate keys of specific values in associative arrays, including handling of strict type comparison and cases where the value is absent.
