This article introduces Spring Boot 4.0.0 preview, built on Spring Framework 7, and walks through five major enhancements—including elegant API versioning, flexible bean registration, null‑safety with JSpecify, simplified HTTP proxy creation, plus several other upgrades and deprecations—complete with code samples and screenshots.
This tutorial introduces Google AutoService, explains Java SPI concepts, shows Maven setup and @AutoService annotation examples, and demonstrates loading translation service providers with ServiceLoader, highlighting how the library automates SPI configuration and reduces errors.
This article explains how to replace numerous static Feign client interfaces with a single dynamic Feign client that can invoke any microservice endpoint at runtime by specifying the service name, URL, and parameters, simplifying code and reducing boilerplate in Spring Cloud applications.
This tutorial explains the differences between Java's System.exit() and Runtime.getRuntime().halt(), detailing their shutdown sequences, impact on shutdown hooks and finalizers, providing code examples and test cases, and offering guidance on when to use each method safely.
This article demonstrates a practical MySQL performance test using a simulated e‑commerce scenario, detailing the user table schema, multithreaded Java code for inserting random user records, parameterized inputs, success counting, and resource management to evaluate and improve registration throughput.
This tutorial explains RocketMQ's delayed message feature, covering its core concepts, implementation using a time‑wheel algorithm, step‑by‑step usage instructions, practical code examples, and important considerations for reliable scheduling in distributed backend systems.
Floating‑point numbers cannot precisely represent many decimal values, leading to cumulative errors in financial calculations, so Java’s BigDecimal class is recommended for high‑precision arithmetic to avoid such inaccuracies and ensure reliable monetary computations.
This article explains the fundamental distinctions between Spring Boot filters and interceptors—including execution timing, scope, registration methods, request handling, modification capabilities, exception mechanisms, and typical use cases—while providing practical code examples for each.
This guide explains how to install jEnv, add and configure multiple JDK versions, set global and local JDKs per project, and integrate the tool with Maven and Gradle to ensure the correct Java version is used across diverse development environments.
This guide explains how to install SDKMAN!, use it to list, install, switch, and set global or project‑specific Java JDK versions, upgrade existing installations, and discover other SDKs, providing a practical solution for frequent Java version changes in microservice development.
This guide explains how to build a Nacos service cluster, configure providers and consumers, write the necessary Spring Cloud Nacos YAML and Java controller code, detail the steps for setting up multiple Nacos nodes, and troubleshoot typical startup errors.
Apache Commons Lang3 provides Pair and Triple classes that let Java developers return multiple related values without custom wrappers, offering immutable and mutable variants, easy Maven integration, and clear APIs for handling key‑value pairs and three‑element tuples, improving code readability and maintainability.
This article explains how Java developers can use ArchUnit to automatically import and analyze compiled classes, define custom architectural rules, enforce package naming conventions, prevent cyclic dependencies, and integrate the library with Maven or Gradle builds to maintain a clean, layered backend architecture.
This guide explains how to identify the root causes of a server's CPU hitting 100%—whether on a database or an application server—by using cloud monitoring, Linux top commands, thread analysis with jstack, and practical Java code fixes such as limiting loops, optimizing locks, and handling GC pressure.
This article provides a comprehensive walkthrough of JDBC for MySQL, covering driver loading, connection creation, statement and prepared statement objects, SQL execution with examples, batch processing, and performance considerations for test engineers using Java.
AIFlowy is a Java‑powered, open‑source, enterprise‑grade AI platform that offers a bot for natural‑language interaction, extensible plugins, a knowledge‑base with RAG support, and visual workflow automation, enabling developers to quickly build and customize AI applications for domestic B2B scenarios.
This article explains the Spring MVC architecture, detailing the roles of DispatcherServlet, HandlerMapping, HandlerAdapter, Controller, ViewResolver, and View within the MVC pattern, while also providing a brief promotional note for IDE activation codes.
This article explains the major enhancements in Spring 6.0 and Spring Boot 3.0—including a JDK 17 baseline, Project Loom virtual threads, @HttpExchange declarative HTTP clients, RFC 7807 ProblemDetail error handling, GraalVM native image support, AOT compilation, OAuth2 server setup, and Micrometer‑Prometheus monitoring—while providing a practical upgrade roadmap and code samples.
The article shares detailed WeChat (wxg) interview experiences from Java and C++ candidates, highlighting the high difficulty, the blend of algorithmic depth and system design breadth, and the extensive range of technical questions that ultimately led both candidates to fail.
This guide shows how to configure Jackson in Spring Boot to consistently format LocalDateTime, Date, and String parameters as "yyyy-MM-dd HH:mm:ss", covering global settings via application properties, field-level @JsonFormat, custom serializers/deserializers, and unified handling in REST controllers.
This article analyzes high‑throughput sensitive‑word filtering by comparing brute‑force, KMP, Trie, double‑array Trie and Aho‑Corasick algorithms, presents their time and space complexities, shows Java implementations for Trie and AC automata, evaluates Netty deployment options, and offers practical optimizations such as asynchronous detection, hot‑reloading, tiered responses, logging and fuzzy matching.
This article introduces the JSON-RPC 2.0 protocol, demonstrates how to integrate the jsonrpc4j library into a Spring Boot 3.4.2 project, and provides step‑by‑step code examples for defining services, exposing them via beans or annotations, configuring various client proxies, handling errors, and implementing streaming socket communication.
This article explains how the @RateLimiter annotation in SpringBoot can replace manual, verbose rate‑limiting code with a concise declarative approach, covering basic usage, custom strategies, real‑world examples, and the benefits of reduced complexity and improved system stability.
This guide explains why and how to use Maven's dependency analysis tool to detect used undeclared and unused declared dependencies, demonstrates the required commands, interprets the warnings, and outlines best‑practice timing and risk considerations for Java backend projects.
This article explains how to refactor a Spring MVC Controller layer by separating responsibilities, implementing a unified response structure, handling String response conversion, customizing validation with JSR‑303, and creating centralized exception handling to produce consistent API results.
This article provides a comprehensive guide to integrating WebSocket in Spring Boot, covering Javax, WebMVC, WebFlux implementations with detailed server and client configurations, as well as brief introductions to Java‑WebSocket, SocketIO, and Netty libraries, including full code examples.
This article introduces the LiteFlow lightweight rule engine, explains its architecture, component types, EL rule files, data context handling, configuration options, and demonstrates a real‑world e‑commerce workflow with code examples, while also noting related promotional offers at the end.
This guide walks Java developers through integrating Spring AI with large‑model services such as DeepSeek, covering setup, API key configuration, code examples for synchronous and streaming calls, reactive implementation, monitoring with Actuator, and compatibility with OpenAI‑style APIs.
Maven‑mvnd introduces a long‑running daemon, GraalVM native execution and seamless Maven compatibility to dramatically reduce build time, lower resource consumption, and improve feedback loops for large or multi‑module Java projects.
This article explains how JWT provides stateless authentication while Session adds an extra security layer and lifecycle management, and demonstrates their combined use with Java code to achieve both scalability and fine‑grained control over user sessions.
This guide walks you through Maven installation, local repository configuration, dependency coordinates, common Maven commands, profile usage, multi‑module project setup, the difference between dependencyManagement and dependencies, and practical Maven tricks such as installing local jars, removing version numbers from generated artifacts, and resolving dependency conflicts.
This guide explains how Maven repositories and mirrors work, the role of the mirrorOf attribute, how to set up central and third‑party repositories in pom.xml, configure mirrors in settings.xml with various matching rules, and properly configure private repository deployment with authentication and profile activation.
The article explains the CopyOnWrite (COW) concept, its read‑write separation benefits for thread‑safe, read‑heavy scenarios, key implementation details in Java’s CopyOnWriteArrayList—including volatile and transient usage—and discusses its memory overhead and eventual‑consistency drawbacks.
Java serialization, while convenient for persisting objects, suffers from versioning issues, hidden fields, mutable data snapshots, performance overhead, security vulnerabilities, singleton breaches, final field tampering, external dependencies, maintenance burdens, and format limitations, and the article recommends explicit serialVersionUID, custom methods, and JSON/Protobuf alternatives.
Learn a step‑by‑step method to integrate a third‑party SDK jar that isn’t in a Maven repository into your Java project by placing the jar in resources, adding a system‑scoped dependency, and configuring the build plugin to include it during packaging.
The article announces the Spring AI 1.0 release, provides the Maven BOM dependency, compares Spring AI with LangChain4j for Java AI development, and outlines upcoming integration, performance, and observability improvements for both frameworks amid rapid large‑model advancements.
This article consolidates essential Java date and time utilities—including start/end calculations for days, weeks, months, quarters and years, time arithmetic, formatting, parsing, and conversions between LocalDateTime, Date, and Instant—providing a handy reference for developers working with the Java Time API.
This article presents a production‑validated solution that combines MyBatis‑Plus auto‑fill, AOP, JWT, multi‑data‑source handling, distributed ID generation, performance tuning, and audit logging to eliminate repetitive maintenance of common fields such as createTime, updateTime, createUser, and updateUser in Java backend order services.
This article introduces OSHI, a free open‑source Java library that uses JNA to provide cross‑platform hardware and operating‑system details, outlines its main features, advantages, and limitations, and supplies complete Maven dependency and Java code examples for building system‑monitoring tools.
This guide walks through the problem of server‑initiated push in a Spring Boot project, explains why WebSocket is needed over HTTP, and provides step‑by‑step Maven setup, configuration classes, controller code, a test HTML page, and troubleshooting tips for proper initialization.
This article explains how to implement a thread‑safe round‑robin load balancer in Java using AtomicInteger, discusses its advantages and limitations, provides sample code for single‑thread and multithreaded scenarios, and suggests further optimizations such as health checks, weighted routing, and dynamic server updates.
The whitepaper outlines Jakarta EE's strategic importance, citing adoption surveys, open‑source benefits, deep ecosystem integration, stability, flexibility for cloud‑native and monolithic architectures, and a vibrant community that together make it a compelling platform for today’s and future Java development.
Spring Boot's @Async annotation enables developers to replace manual thread and thread‑pool management with simple method annotations, providing automatic asynchronous execution, customizable thread pools, and flexible return types such as Future and CompletableFuture, thereby streamlining code, improving efficiency, and reducing complexity in backend services.
This article demonstrates how to integrate Project Loom virtual threads into a Spring Boot application, provides the necessary Maven configuration and Java code, runs load tests with JMeter to compare response times against traditional threads, and shows the significant throughput improvements achieved on the same hardware.
When a JSON payload contains unpredictable fields, Jackson’s @JsonAnySetter and @JsonAnyGetter let you capture those dynamic properties into a Map during deserialization and seamlessly emit them during serialization, eliminating the need for rigid POJOs.
This article explains how to combine Elasticsearch and MySQL in a Spring Boot backend by selecting the technology stack, creating a shared Elasticsearch package, defining ES and MySQL entity classes, implementing repository and mapper interfaces, writing service logic, and demonstrating query testing.
This article explains how SpringBoot's @PathVariable annotation automatically binds URL path parameters to method arguments, simplifying RESTful API development, reducing boilerplate code, and improving maintainability, with examples and advanced usage tips for developers.
This article walks through a practical approach to generate a unique traceId at request entry, propagate it through REST, RocketMQ, and Dubbo RPC modules, and configure Log4j2 to print the traceId so that logs from different services can be correlated into a single request chain.
This article explains how to create three Java threads that print the characters A, B, and C in strict order, repeat the sequence twenty times, and demonstrates three implementations—unordered printing, ordered printing with Semaphore, and a looped version—complete with full source code examples.
This article investigates the reasons behind Spring Boot's slow startup by examining the macro initialization flow, pinpointing time‑consuming stages such as environment preparation and bean refresh, and providing profiling code examples to help developers understand and optimize the boot process.
This article discusses the motivations, comparative analysis, and practical steps for refactoring a Java backend project by replacing MongoDB with MySQL, covering pain points, selection criteria, schema redesign, entity mapping, and sample query code.
This tutorial walks you through obtaining or generating SSL certificates, configuring Spring Boot to use JKS or PKCS12 keystores, redirecting HTTP to HTTPS, and distributing the certificate to clients, with complete command‑line examples and code snippets for a production‑ready setup.
Discover twelve practical SpringBoot performance optimization techniques—from connection pool tuning and JVM memory settings to caching, async processing, and full‑stack monitoring—each illustrated with code snippets and actionable guidance to prevent full‑table scans, OOM errors, and latency spikes in high‑traffic applications.
This article presents advanced WebSocket testing techniques—including asynchronous connection creation, result statistics, price verification, latency measurement, TPS modeling—and demonstrates a Netty‑WebSocket subscription test for 10,000 users plus Java‑ and Netty‑based keepalive implementations for high‑concurrency scenarios.
This article explains how SpringBoot’s @Cacheable annotation automates cache handling, reducing boilerplate code, improving performance, and simplifying maintenance, while also covering related annotations like @CacheEvict and @CachePut, with practical code examples for user and product data caching in real-world applications.
This article explains why a Spring Boot application fails to locate a template file when packaged as a JAR, details the step‑by‑step debugging process, and provides code solutions using ClassPathResource or PathMatchingResourcePatternResolver to correctly read resources inside the JAR.
This article demonstrates how to securely upload files to Minio, stream them for preview via KKFile without exposing the Minio endpoint, and protect download URLs with token validation, providing complete Java code examples for upload, download, and preview URL generation.
This article introduces 17 practical Java utility classes—including Collections, CollectionUtils, Lists, Objects, BooleanUtils, StringUtils, Assert, IOUtils, MDC, ClassUtils, BeanUtils, ReflectionUtils, Base64Utils, StandardCharsets, DigestUtils, SerializationUtils, and HttpStatus—showing how to use them with clear code examples to streamline everyday development tasks.
This article explains how to prevent image hotlinking in a Spring Boot application by creating a simple interceptor with hard‑coded settings and then extending it to a flexible, configuration‑driven solution using application.yml and a properties‑mapping class.
This article explains what JVM thread dumps are, why they are crucial for fault testing, outlines common scenarios such as deadlocks and resource leaks, and provides step‑by‑step methods—including jstack, kill‑3, VisualVM, programmatic APIs, and Fabric8‑driven Kubernetes automation—to capture and analyze them effectively.
This article walks through eleven notable Spring Boot 3.5 enhancements—including stricter .enabled flags, renamed TaskExecutor beans, Redis URL handling, annotation‑based servlet/filter registration, multi‑property environment loading, structured logging tweaks, WebClient connector settings, task decorators, custom executors, bootstrapExecutor auto‑configuration, and secured heapdump actuator endpoint—providing concise explanations and runnable code snippets.
This article explains how the @Valid annotation in Spring Boot can automatically enforce bean validation, replace verbose manual checks, support custom validators, and greatly reduce boilerplate code when handling complex form inputs in backend applications.
This article demonstrates how to implement a real‑time device‑monitoring system using WebSocket, covering the problem scenario, front‑end Vue.js visualization, Spring Boot back‑end configuration, WebSocket server setup, and step‑by‑step testing to achieve instant status updates.
This article explains the six Java thread states defined in Thread.State, demonstrates how to use the Arthas diagnostic tool to identify blocked, waiting, or timed‑waiting threads, and provides practical strategies for diagnosing and optimizing thread‑blocking issues in Java applications.
A comprehensive guide presenting thirty proven Java optimization techniques, from efficient string handling and buffered I/O to proper resource management, connection pooling, multithreading, naming conventions, and safe use of APIs, each illustrated with concise code examples.
This guide walks you through designing, implementing, and analyzing a Java‑based performance test for a WebSocket product‑query interface, covering request/response formats, thread‑driven load generation, TPS control, console metrics, and response validation techniques.
This article examines the common pain points of on‑call debugging, explains how to extract useful information from error screenshots, and presents a Java‑based method call stack tracing tool that filters and visualizes stack frames to quickly locate code origins and improve troubleshooting efficiency.
This article explains why repetitive logger boilerplate in Spring Boot is a problem, introduces Lombok's @Slf4j annotation that auto‑generates a logger, shows basic and advanced usage with code examples, and outlines the benefits for real‑world backend projects.
The article describes the challenges of testing complex systems, proposes a traffic‑replay platform built on Java and jvm‑sandbox‑repeater, outlines its four‑stage construction, layered architecture, core functions, technical challenges with solutions, and future integration plans to improve automated testing and reduce noise.
This article explains the Aho‑Corasick automaton, a classic multi‑pattern matching algorithm that builds a Trie with fail pointers to achieve linear‑time search over massive keyword sets, and demonstrates a Java implementation for highlighting keywords in HTML documents.
This article explains the Aho‑Corasick automaton, detailing its construction, fail‑pointer mechanism, linear‑time complexity, and practical Java implementation for highlighting keywords in HTML, demonstrating its power for massive real‑time text search.
This article introduces MapStruct, a compile‑time Java bean‑mapping framework, and demonstrates advanced features such as expression‑based mappings, qualifiedByName for custom conversions, nullValueMappingStrategy for handling nulls, and the use of Decorator classes to apply global post‑processing logic.
Spring AI 1.0 GA introduces a comprehensive suite of AI capabilities for Java developers, including a ChatClient supporting 20 models, vector‑store integrations, RAG pipelines, advanced chat memory, @Tool function calling, model evaluation, observability, Model Context Protocol, and autonomous agents, with examples for major cloud providers.
The article explains how to achieve graceful shutdown of Spring Boot services by handling Linux kill signals, registering JVM shutdown hooks, and exposing an Actuator REST endpoint that safely releases resources, stops beans, and terminates the JVM without data loss.
This article explains the six Java thread states defined in java.lang.Thread.State, describes the meaning of each state, illustrates the possible state transitions, and provides three runnable code examples that demonstrate NEW, RUNNABLE, BLOCKED, WAITING, TIMED_WAITING and TERMINATED states along with their console outputs.
This article explains the concepts of Data Transfer Object (DTO), Business Object (BO), Persistent Object (PO), and Value Object (VO) in backend development, shows how they differ and interact across layers, and provides Java code examples and a global configuration to filter null fields during serialization.
This article explains the challenges of integrating diverse tools without MCP, then demonstrates step‑by‑step how to configure Spring‑AI and the native MCP SDK to call LLMs, register tools, handle SSE and stdio services, and troubleshoot common issues, providing code snippets and best‑practice recommendations.
This article walks you through using Spring AI's MCP client starter in a Spring Boot 3 project to connect to Baidu Map's MCP server, covering dependencies, YAML and JSON configurations, communication modes, custom server setup, and sample code for invoking the service.
When handling complex forms in SpringBoot, developers often write repetitive code to extract each field, but the @ModelAttribute annotation automatically binds all form parameters to Java objects, reducing boilerplate, improving readability, and supporting custom binding scenarios.
This article analyses why Spring Boot startup can take dozens of seconds, breaks down the most time‑consuming phases such as prepareEnvironment and refreshContext, shows profiling code and screenshots, compares a simple MVC demo with a real‑world project, and identifies external client connections and configuration loading as the biggest bottlenecks.
This article shares ten practical rules for producing high‑quality logs in Java backend systems, covering unified formatting, stack traces, log levels, complete parameters, data masking, asynchronous logging, traceability, dynamic level adjustment, structured storage, and intelligent monitoring to help developers quickly diagnose issues and improve system reliability.
This article explains how to split a multi‑function OpenAPI endpoint into independent steps using the responsibility‑chain pattern in Spring, detailing the abstract component, context sharing, bean retrieval via ApplicationContext, and a controller that dynamically orders execution through a query parameter, with full code examples.
This article explains why consistent Java code style matters, reviews major industry standards such as Google and Alibaba, guides the selection and customization of a style guide, and demonstrates how to configure IntelliJ IDEA, Checkstyle, and Maven to enforce the rules throughout development.
This article explores the importance of Java code style guidelines, compares major industry standards such as Google Java Style and Alibaba's conventions, and provides step‑by‑step instructions for configuring IDEs and Maven plugins to enforce consistent, readable code across teams.
This article explains how using a custom @DistributeLock annotation together with @Transactional can cause idempotency issues due to aspect execution order, and demonstrates how to prioritize the lock aspect using @Order to ensure the lock is applied before the transaction, with code examples and best‑practice recommendations.
This article explains how to efficiently handle exceptions in Spring Boot applications by using @ControllerAdvice and @ExceptionHandler annotations, providing step-by-step code examples for custom global exception classes, error response structures, and handling specific exceptions such as business, null pointer, and type conversion errors.
This article explains how to use the poi‑tl Java library to create Word report templates, define common tags such as text, images, tables, lists, and charts, encapsulate them with enums and factories, and generate complete reports through a reusable utility class.
During a major promotion a huge activity generated an oversized Redis cache key that caused cache‑penetration, saturated network bandwidth, and triggered a cascade of service failures, prompting a detailed root‑cause analysis and a set of mitigation and prevention measures.
This article explains how to design, configure, and operate an Activiti workflow engine in a Java Spring Boot application, covering BPMN diagram creation, engine setup, deployment, task handling, code examples, API usage, and comparisons with other workflow solutions.
This article provides an in‑depth analysis of the Java ConcurrentHashMap implementation, covering its constructor logic, hash‑table sizing, the core put and get operations, element counting with addCount, multi‑threaded resizing via transfer, treeification of bins, removal, computeIfAbsent, and the design choices that forbid null keys and values to simplify concurrency handling.
This article provides a thorough, English‑language walkthrough of Java 8+ ConcurrentHashMap’s source code, covering its constructor logic, load‑factor handling, CAS‑based insertion, node optimizations, the put method, element‑count updates, multi‑threaded resizing, treeification, and auxiliary operations such as get, remove, and computeIfAbsent.
The article examines why many programmers favor if...else over switch statements, outlining switch's intended clarity, its limitations such as lack of range support and fall‑through pitfalls, performance considerations across languages, and scenarios where each construct shines.
This article explains why both front‑end and back‑end data validation are essential for secure and user‑friendly web applications, introduces Java Bean Validation annotations, shows how to integrate them with Spring MVC, and compares common Java permission‑control frameworks such as Spring Security, Shiro and Sa‑Token.
This article demonstrates how to use Java 8's Function and SFunction functional interfaces together with lambda expressions to abstract and reuse data‑validation logic, dramatically reducing repetitive code, improving readability, and enabling flexible, generic validation across various backend entities.
This article provides a comprehensive guide for Android developers on how to connect and use serial ports, USB peripherals, printers, barcode scanners, payment boxes, keyboards, and mice, including required permissions, configuration steps, and sample Kotlin/Java code snippets for each device type.
This article introduces Spring Cloud Gateway as a high‑performance replacement for Zuul, explains its core components (Route, Predicate, Filter) and request flow, provides step‑by‑step setup of a gateway project, demonstrates route configuration, custom GlobalFilter and GatewayFilter implementations, and validates the behavior with example requests.
This article explains the behavioral Strategy design pattern, describes its definition and structure, demonstrates a real‑world e‑commerce discount scenario with both a tangled if‑else implementation and a clean refactoring using Java interfaces, concrete strategy classes, a context, and a client, and finally discusses its advantages and drawbacks.
This article presents six commonly used file upload and download techniques for Spring Boot, covering basic Multipart handling, stream-based download, integration with Alibaba Cloud OSS and MinIO, as well as high‑concurrency chunked uploads with Nginx, each accompanied by complete code examples and usage scenarios.
This tutorial shows how to build and run a Spring MVC application using an embedded Tomcat server with just a single Java class, covering Maven dependencies, Tomcat configuration, Servlet registration, Spring‑driven startup, and core Spring MVC component setup.
When a midnight CPU alarm triggered, I logged into the server, identified runaway Java processes, profiled the JVM, refactored a costly sorting algorithm, added database indexes, containerized the service, and set up Prometheus alerts, ultimately reducing CPU usage below 30% and restoring millisecond response times.
