This article explains how the PHP mysqli_query function works with MySQL, provides a complete example for executing SELECT queries, and discusses its use for INSERT, UPDATE, DELETE operations along with result handling and related fetching functions.
This article provides a step‑by‑step guide for integrating Alipay sandbox payment into a Spring Boot backend, covering sandbox configuration, network tunneling, Maven SDK dependency, application properties, payment request creation, callback processing, and common troubleshooting.
This article explains RabbitMQ's transaction mechanism, outlines its basic workflow, core channel methods, provides a Java example, compares its advantages and disadvantages with the confirm mode, and offers guidance on choosing the appropriate approach for different scenarios.
This article explains how TCP connection setup, slow‑start, delayed acknowledgments, the Nagle algorithm, TIME_WAIT and file‑descriptor limits affect HTTP performance, and shows how to tune Nginx and Linux keep‑alive settings to achieve faster, more reliable web traffic.
This article explains the typical reasons why Spring @Transactional annotations may fail—including AOP proxy limitations, method visibility, self‑invocation, exception handling, propagation settings, async execution, multiple data sources, and database constraints—and provides practical solutions to ensure reliable transaction behavior.
The article explains what CORS is and presents four main approaches—using simple and pre‑flight request headers, configuring Nginx as a reverse proxy, adding a SpringBoot CorsConfig or CorsFilter bean, and delegating CORS to an API gateway—so developers can resolve cross‑origin issues in SpringBoot applications.
This guide walks through converting a traditional Spring Boot book‑management API into a Model Context Protocol (MCP) service that can be invoked via natural‑language prompts, covering dependency setup, proxy configuration, @Tool annotations, MCP server registration, chat client wiring, data initialization, and end‑to‑end testing.
This article narrates the messy history of API design, illustrating early AJAX conventions, the misuse of HTTP status codes, the challenges of maintaining Restful standards, ad‑hoc extensions, and the eventual abandonment of Restful in favor of a simplified POST‑centric approach, while highlighting practical lessons for backend developers.
This article explains two common approaches for configuring Java thread pools—static sizing based on CPU‑bound or I/O‑bound workloads and a formula‑driven method—then critiques their limits in real systems and introduces DynamicTp as a flexible, monitoring‑enabled alternative with code examples and architectural details.
This article explains how to improve the stability and maintainability of API automated tests by defining custom exception classes, wrapping a Loguru‑based logger, and integrating both into request utilities and pytest test cases with clear code examples.
The article explains how RocketMQ ensures strict message ordering through global FIFO queues and partitioned ordering, covering use cases, key implementation techniques on the producer, broker, and consumer sides, as well as lock mechanisms, retry strategies, and fault‑tolerance design.
This article explores the challenges of data consistency in RPC timeout scenarios, especially when idempotency fails, and introduces a lightweight mock/spy tool that can dynamically configure mock responses for any method call, helping restore consistency without full transaction support.
This article analyzes the coupling problems caused by multiple controller calls and third‑party push interfaces, proposes a TPS microservice to centralize third‑party interactions, demonstrates Java Feign interfaces and enum‑based routing, and shows how backend and frontend can achieve low‑coupling architecture while reducing code duplication.
In high‑concurrency Java applications, LongAdder—introduced in JDK 8 and using partitioned cells to reduce contention—generally outperforms the single‑value AtomicLong, which relies on CAS and can cause CPU waste under heavy load, so Alibaba advises LongAdder for scalable distributed counters, though memory usage and workload specifics must be considered.
This article explains why AIGC services need queueing systems and rate‑limiting, describes the user‑facing behaviors of both mechanisms, outlines design goals, compares queue and limiter implementations, and provides practical guidance on selecting middleware, monitoring, and integrating them into a production workflow.
This article demonstrates how Java 8's functional interfaces, especially Function and SFunction, can be used to abstract and reuse data‑validation logic, dramatically reducing boilerplate code, improving readability, and making validation rules easier to maintain and extend.
This article compares four major API architectural styles—RPC, SOAP, REST, and GraphQL—by detailing their mechanisms, advantages, disadvantages, and typical use cases, and then provides guidance on selecting the most suitable style based on language, environment, and resource constraints.
This article explains Redis eviction policies, how the eviction process works, and practical solutions for cache penetration, breakdown, and avalanche, helping developers choose the right strategy and optimize cache performance under high load.
This article analyzes unexpected behaviors caused by PageHelper in a Java backend project, such as duplicate user registration, limited query results, and password‑reset errors, and explains how ThreadLocal pagination parameters, startPage(), and cleanup mechanisms lead to these problems while offering practical debugging tips.
This article compiles a two‑week research of Python web frameworks, explaining what a web framework is, why it is used, and providing a ranked list of over twenty‑five frameworks with official links, strengths, and weaknesses to help developers choose the most suitable tool for their projects.
This article explains the distinction between errors and exceptions in Go, outlines when to use error returns versus panic/recover, and provides a series of practical patterns with code examples to write clearer, more maintainable backend code.
The article explains why designing RPC interfaces with generic Result objects that contain errorCode, errorMessage and data defeats RPC's purpose, and demonstrates how returning plain business objects and leveraging Java exceptions leads to cleaner, more maintainable backend code.
The article explains why the Java JVM throws java.lang.OutOfMemoryError: Unable to create new native threads, outlines common causes such as thread leaks, insufficient RAM, other processes, and kernel limits, and provides practical solutions and troubleshooting steps to resolve the issue.
This article explains how the Jackson @JsonView annotation can be used in Spring back‑end projects to selectively serialize object fields, reduce bandwidth, improve security, and handle nested associations by defining view interfaces and applying them on entity fields and controller methods.
This comprehensive guide explains the most common Spring MVC and Spring Boot annotations—including @RequestMapping, @GetMapping, @Autowired, @Component, @Scope, and conditional annotations—detailing their purposes, configuration attributes, and practical code examples to help Java backend developers write cleaner, more maintainable code.
This article explains the technical selection between JWT and session for authentication, compares their differences, advantages, and disadvantages, and provides a complete Java implementation—including token generation, Redis storage, login/logout, password update, and request interception—demonstrating why JWT was chosen for a distributed backend system.
This article explains the concept of prefix sums, demonstrates how to build and use a prefix‑sum array in PHP with clear code examples, and discusses when the technique is advantageous and its limitations, enabling O(1) interval sum queries after an O(n) preprocessing step.
This document presents a comprehensive set of Cursor development rules covering backend (Golang/Java), frontend (TypeScript with React/Vue), and Android (Kotlin/Java) environments, including general principles, automation and safety policies, code quality optimization, architecture awareness, and change traceability, with copy‑ready appendices.
This article explains why rate limiting is essential for high‑traffic services, compares four classic algorithms (fixed‑window, sliding‑window, leaky‑bucket, token‑bucket), provides Java and Redis implementations, shares production case studies, highlights common pitfalls, and offers performance‑tuning tips for robust backend systems.
Learn how to install Go, set up the httpstat tool, and use it to break down HTTP request phases—DNS lookup, TCP connection, TLS handshake, server processing, and content transfer—to quickly pinpoint network or service latency issues.
This article details the end‑to‑end design, configuration, and code implementation of a sharding solution for loan and repayment tables, covering database schema changes, historical data migration, dynamic synchronization switches, transaction handling, and practical pitfalls when using Spring Boot 3 with ShardingSphere.
This article explains Domain-Driven Design (DDD), contrasting it with traditional layered development through clear examples, outlines key DDD building blocks such as aggregate roots, domain services, and events, and discusses when DDD is appropriate for complex, frequently changing business domains.
This article introduces a reusable asynchronous processing SDK built on Spring, Kafka, and MySQL that leverages @AsyncExec annotations, transactional event listeners, and configurable thread pools to ensure reliable, non‑blocking execution, data consistency, and fault‑tolerant handling of business logic in backend applications.
This article explains how to encapsulate common assertion logic—such as status‑code, JSON data, and database assertions—within the Pytest framework, providing reusable functions and a generic assertion class to improve readability, maintainability, and efficiency of backend API tests.
This article presents a curated collection of 110 Spring Boot 3 practical examples, covering @Profile usage, PropertySource configuration, resource loading, bean validation, and automatic proxy creation, providing developers with hands‑on code snippets and clear explanations to enhance backend development skills.
This article explains why simple GET‑modify‑SET inventory updates cause overselling in flash‑sale spikes and presents several Redis‑based solutions—including Lua scripts, WATCH‑based optimistic locks, distributed SETNX locks, and asynchronous queue processing—detailing their implementation, advantages, and trade‑offs.
This article explains the evolution from Spring AI FunctionCall to the newer ToolCalling, introduces the Model Context Protocol (MCP), and provides step‑by‑step code examples for building MCP servers and clients in Java, demonstrating how to integrate large language models with backend services.
This article provides a comprehensive guide to integrating WebSocket in Spring Boot, covering the native Javax API, Spring WebMVC and WebFlux approaches, as well as popular third‑party libraries such as Java‑WebSocket, SocketIO and Netty, with detailed configuration steps, code examples, and practical tips.
This article explains server‑push scenarios such as real‑time dashboards and chat, compares three implementation methods—polling, WebSocket, and SSE—details the advantages and drawbacks of each, and provides step‑by‑step Node.js and frontend demos for using SSE in web applications.
This article explains the purpose, core methods, and practical scenarios of Spring Framework’s ResponseBodyEmitter, compares it with SSE and raw streaming, and provides a complete Spring Boot controller example that demonstrates how to implement real‑time log streaming and other asynchronous HTTP responses.
This article explains the concept of rate limiting in system design, covering its importance, common use cases, various types, popular algorithms such as token bucket and leaky bucket, implementation across different system layers, and the challenges associated with configuring and scaling rate‑limiting solutions.
Java’s HashMap stores entries in a hash‑based array where a key’s hash determines the bucket index, resolves collisions with linked lists that become red‑black trees for long chains, resizes when the load factor exceeds 0.75, and requires ConcurrentHashMap for safe multithreaded updates, a core concept often asked in interviews.
This article explains how to set up a dynamic IP blacklist using Nginx, Lua scripts, and Redis, covering environment preparation, design options, configuration of nginx.conf, Lua script implementation, and advanced features such as rate limiting, white‑listing, and automated detection to protect servers from malicious traffic.
This article analyzes why traditional Excel import methods crash under massive loads and presents four practical optimization techniques—including streaming parsing, batch inserts, asynchronous processing, and parallel sharding—backed by code samples, configuration tips, and real‑world performance benchmarks for importing millions of rows efficiently.
This article presents a simple basketball information management system built with Django, detailing CRUD operations for player data, pagination logic, and corresponding HTML templates for both admin and front‑end interfaces, accompanied by full source code snippets and screenshots of the resulting pages.
The article explains PHP's rename() function, detailing its syntax, required source and target parameters, return values, practical code examples for renaming files and directories, and important considerations such as permissions and error handling.
The 2025 PHP ecosystem overview details the language’s new features such as enhanced generics and fibers, performance improvements via JIT and OPcache, evolving best practices, the latest trends in major and micro frameworks, modern design pattern implementations, cloud‑native deployment, AI integration, and future directions.
This tutorial explains how to use the AMap (Gaode) Map API in PHP to add a map zoom feature to a web page, covering API key acquisition, library inclusion, map instance creation, container setup, initial zoom level, control addition, and final display with complete code examples.
The article explains how Nginx's try_files directive, introduced after version 0.7, attempts to serve static files by checking the $uri and $uri/ variables, falls back to a named location when files are missing, and can replace traditional rewrite rules for more efficient request handling.
This article explains the Model Context Protocol (MCP) for seamless LLM integration, describes its background, presents a sequence diagram of its architecture, and provides step‑by‑step Java SpringBoot code for SSE streaming, HTTP POST handling, and annotation‑based tool registration.
This article introduces a unified log recording solution for Java backend services, covering the background need, expected UI effects, database schema, core principles, detailed annotation and service implementations, and multiple usage scenarios including simple log objects, inheritance, and nested objects.
This guide explains the concepts of strong (expires‑based) and weak (validation‑based) HTTP caching, details the relevant response headers, provides Nginx configuration examples for each strategy, compares their behaviors and suitable use cases, and offers best‑practice tips and debugging tools to improve website performance.
SpringBoot 3.0 eliminates the long‑standing spring.factories file due to startup performance penalties, lack of modular support, static configuration limits, and incompatibility with GraalVM native images, and replaces it with a set of imports files that provide clearer, faster, and more modular auto‑configuration registration.
This article introduces Liteflow, a lightweight yet powerful Java rule engine, explains its architecture, demonstrates how to configure and use it with Spring Boot, shows component types and EL rule files, and provides a real‑world e‑commerce workflow example with code snippets.
This article introduces the SaloonPHP Laravel Plugin, explains how to install it, demonstrates creating request classes and using them in services, and highlights features like caching and retries that streamline API request management in Laravel projects.
This guide explains how to use Composer to install WP‑CLI and then leverage WP‑CLI core commands to quickly download, install, update, and convert a single‑site WordPress installation into a multisite network, reducing manual effort and errors.
This article explains the fundamentals of QR code login, detailing how QR codes convey unique IDs, the token‑based authentication process, the steps from QR generation to device verification, and the security considerations involved in implementing scan‑to‑login across web and mobile platforms.
This article explains how to install and use the league/mime-type-detection library in PHP to reliably detect MIME types via file content, extensions, or both, offering code examples, lookup features, and a discussion of its advantages for backend file‑handling systems.
This guide details a secure third‑party API design, covering API key generation, request signing with timestamps and nonces, permission division, CRUD endpoint definitions, unified response structures, and best‑practice security measures such as HTTPS, IP whitelisting, rate limiting, logging, and idempotency handling.
This article describes a lightweight, non‑intrusive MyBatis plugin that adds identifiable coloring comments to SQL statements—embedding statementId, pFinderId, and optional custom data—to simplify SQL source tracing, improve slow‑SQL analysis, and support SELECT, INSERT, UPDATE, DELETE operations with minimal performance overhead.
This article explains how Spring Framework's ResponseBodyEmitter enables real‑time, chunked HTTP responses for use cases such as log streaming, progress updates, chat, and AI output, detailing its advantages over SSE, usage scenarios, core methods, a complete controller example, and best‑practice considerations.
This article presents nine practical techniques—including the Strategy pattern, lambda maps, Optional chaining, ternary operators, enums, early returns, condition merging, and rule engines—to replace cumbersome if‑else chains in Java, offering cleaner, more maintainable and performant code for Spring Boot developers.
This article explains Nginx's location matching order, distinguishes literal and regex locations, clarifies the effects of prefixes like =, ^~, and @, provides detailed configuration examples, test results, and installation tips for the rewrite module.
This article explains how view‑driven (or BFF) API design replaces bulky data‑centric interfaces with UI‑aligned response models, reducing data redundancy, eliminating logic leakage, and streamlining front‑back collaboration for faster, more reliable product delivery.
This article explains how to create and display heatmaps in a PHP project by integrating the Baidu Map API, covering prerequisite setup, library inclusion, data preparation, heatmap generation using the HeatMap class, and rendering the map with JavaScript on a web page.
This tutorial explains how to add request rate limiting to a FastAPI application using the SlowAPI library, covering both IP‑based limits and custom token‑based strategies, with installation steps, code examples, and best‑practice recommendations.
This article demonstrates how to use Python's requests library to perform chained API calls—login, create user, retrieve user details, and update user information—while handling exceptions, logging, and environment configuration for robust automated testing.
This article outlines a fraud‑detection use case that leverages Redis GEO commands to compare user order addresses with known malicious locations, discusses technology choices among MySQL, Redis, and Elasticsearch, explains Redis’s Sorted‑Set and GeoHash implementation, and provides Java code examples for GEOADD, GEOPOS, GEODIST, and GEORADIUS.
The article reviews key Java backend interview topics—including thread‑safe collections, JVM memory layout and heap tuning, Full GC troubleshooting, Java 8 features, optimistic locking, stock‑over‑sell handling with Redis, MySQL scaling, cache‑consistency patterns, anti‑bot safeguards, and Bloom filters—while noting JD’s recent 30% salary hike for algorithm engineers.
This article presents a series of PHP function replacements—such as using isset() instead of array_key_exists(), strpos() over strstr(), pre‑increment ++$i, foreach over for, json_encode()/json_decode() instead of serialize()/unserialize(), strict === over ==, and implode() rather than string concatenation—to boost code speed without altering business logic.
This article presents ten practical techniques—including redundant deployment, circuit breaking, traffic shaping, auto‑scaling, gray releases, downgrade switches, full‑link stress testing, data sharding, chaos engineering, and three‑layer monitoring—to dramatically improve system high‑availability from 99% to 99.99% in production environments.
This article examines typical Go error handling pitfalls—including misuse of panic, improper error wrapping, incorrect error comparisons, and neglecting error checks—provides illustrative code samples, explains their potential impacts, and offers best‑practice recommendations to write robust, maintainable Go programs.
This article introduces the devkeep/tools PHP package, explains how to install it, lists its extensive utility functions for data handling, and provides concrete code examples demonstrating tasks such as array sorting, tree classification, Excel export, QR code generation, and email sending.
The article outlines eighteen critical considerations for designing backend interfaces, ranging from documentation format and unified parameter schemas to encryption, idempotency, versioning, and monitoring, providing interview-ready insights that can impress hiring managers.
The article demonstrates how, with Cursor’s AI‑assisted coding and its YOLO mode, a developer can rapidly build a full‑stack license‑approval system—Vue 3 front‑end, Go/Gin back‑end, JWT authentication, MySQL storage—in under a day of effort, highlighting practical tips, limitations, and the broader potential for low‑code creation.
This article explores comprehensive strategies for capturing business operation logs in a Spring‑based system, comparing three solutions—from a simple AOP‑annotation approach, through an enhanced AOP + SpEL method, to a robust Binlog‑plus‑time‑window architecture—while weighing their advantages, drawbacks, and implementation details.
This article provides a step‑by‑step tutorial on using the Flowable BPMN engine within a Spring Boot project, covering workflow fundamentals, key concepts, Maven dependencies, BPMN diagram creation, service task implementation, runtime APIs, unit testing, and common troubleshooting tips.
This article explains how to compress large objects with GZIP before storing them in Redis, demonstrates the pitfalls of not closing streams, shows how Java's try‑with‑resources simplifies resource management, and provides best‑practice code examples to prevent hidden IO exceptions.
The article describes how a Java-based supermarket checkout performance test was refined by adding gender-specific rest intervals—2 minutes for male cashiers and 5 minutes for female cashiers—through code changes that introduce a gender attribute, rest logic, and integration into the test workflow.
This article outlines the systematic thinking process for API automation testing, details the hardware and software environment setup, and provides practical recommendations such as mastering HTTP, using JSONPath, integrating tests into CI/CD pipelines, and addressing performance and security concerns.
RocketMQ’s message tracing feature records each message’s full lifecycle—including producer, broker, and consumer details such as timestamps, latency, and success flags—by enabling traceTopicEnable, creating an internal RMQ_SYS_TRACE_TOPIC, and allowing custom trace topics for fast diagnostics, end‑to‑end tracking, monitoring, and audit compliance.
This article examines how delayed or inconsistent inventory synchronization leads to costly overselling and deadstock in e‑commerce, presents three destructive synchronization patterns, and offers a step‑by‑step guide—including real‑time messaging, distributed locks, rule‑engine integration, and intelligent alerts—to transform inventory management from a liability into a self‑healing system.
This article explains the concept of idempotency, outlines scenarios where it is essential, analyzes common causes of idempotency problems, and presents a comprehensive set of solutions—including unique constraints, optimistic and pessimistic locks, distributed locks, token mechanisms, state machines, deduplication tables, and global request IDs—accompanied by practical code examples and database design guidelines.
Optimizing PHP applications involves a combination of code-level improvements—such as caching, efficient algorithms, and query optimization—and server-side configurations like upgrading PHP, enabling opcode caches, tuning web servers, and leveraging CDNs, along with monitoring tools and asynchronous processing to achieve faster, more scalable performance.
This article explains Go's socket programming workflow, the versatile net.Dial function for TCP, UDP, and ICMP connections, provides complete ICMP and TCP example programs, and then covers HTTP client usage with net/http, including basic methods, form posts, and custom request handling.
This article outlines a step‑by‑step API testing workflow—from defining objectives and analyzing requirements to designing test cases, setting up environments, executing tests with tools like Postman and pytest, analyzing results, integrating into CI/CD pipelines, and applying best practices for continuous improvement.
This article explores seven practical retry solutions—from simple loops and Spring Retry to Resilience4j, message queues, scheduled tasks, two‑phase commits, and distributed locks—explaining their scenarios, core code, and how they prevent costly system failures.
The article analyzes a server outage triggered by a module that repeatedly created a scheduled task without proper lifecycle control, examines the problematic Java code, lists four key issues, presents a corrected implementation, and reflects on development, testing, review, and logging practices to prevent similar incidents.
This article explains how to dynamically switch between multiple service providers, such as SMS vendors, in a Spring‑based backend by using spring‑smart‑di's @AutowiredProxySPI and related annotations, covering configuration, Maven dependency, enabling the feature, and custom proxy implementations.
This article explains the purpose and usage of PHP's curl_multi_getcontent() function, demonstrates how to combine it with curl_multi_init() and curl_multi_exec() for concurrent requests, and provides a complete example showing initialization, execution, content retrieval, and cleanup of multiple cURL handles.
This article examines six frequent Go string pitfalls—including misuse of rune, incorrect iteration, inefficient concatenation, unnecessary conversions, substring memory leaks, and improper trim functions—explaining their impact, demonstrating flawed code, and providing optimized examples to improve correctness and performance.
This article explains RocketMQ's message tracing feature, covering its definition, key data attributes, core benefits, configuration steps for both normal and IO‑isolated modes, the underlying implementation mechanism, supported trace topics, and provides complete Java code examples for custom TraceTopic usage and verification.
Compressing HTTP responses with Nginx gzip improves user experience by reducing load times and cuts bandwidth costs, while proper directives, static gzip handling, and awareness of common misconfigurations ensure optimal performance in production environments.
This article demonstrates how to create a PDF template by first designing a Word document, converting it to PDF, inserting text, option, and image fields using a PDF editor, and then programmatically filling those fields with Java iText code, including dependency setup and image insertion.
This article introduces Spring Framework's ResponseBodyEmitter, explains its advantages over SSE for asynchronous HTTP responses, demonstrates practical usage with a real‑time log‑streaming example, outlines core methods, working principles, best‑practice considerations, and compares it with traditional Streaming and Server‑Sent Events.
This article explores the evolution, architecture, design preparation, processing flow, front‑end/back‑end considerations, configuration strategies, and diverse real‑world examples of checkout systems across medical, e‑commerce, entertainment, ETC, and gaming domains, highlighting how business needs shape payment experiences.
This article explains the Java BigDecimal class, its internal fields and methods, demonstrates a test case, and analyzes the add operation to show how scaling numbers to long integers preserves exact precision in financial calculations.
This article explores why many developers rarely use thread pools, demonstrates a SpringBoot‑Dubbo demo to reveal hidden thread pools in web containers and RPC frameworks, and offers practical guidance on when to tune existing pools versus adding custom ones for optimal performance.
This article explains five common multi‑tenant implementation patterns—independent databases, shared database with separate schemas, shared tables, hybrid approaches, and containerized isolation—detailing their isolation levels, cost implications, scalability, and suitable use cases for SaaS applications.
This article explains how PHP's built-in json_decode function converts JSON-formatted strings into PHP variables, demonstrating both object and associative array outputs with code examples, and shows how to adjust parameters to obtain the desired data structure.
