This guide presents a curated list of 30 essential IntelliJ IDEA plugins, covering code assistance, UI enhancements, project management, and productivity tools, with installation tips and screenshots, helping Java developers transform their IDE into a powerful one‑stop development environment.
This article explains how to improve PostgreSQL IN‑query performance in Spring Boot applications by splitting large IN parameter lists into smaller batches, executing them concurrently with a custom AOP annotation, and merging the results, providing a reusable annotation‑driven solution for high‑throughput backend services.
This article walks through diagnosing slow API responses, using Pfinder for tracing, refactoring Java collection handling with Sets, and applying JSF asynchronous calls to dramatically cut latency, offering a step‑by‑step guide to backend performance optimization.
This article explains the four standard Java ThreadPoolExecutor rejection policies—AbortPolicy, CallerRunsPolicy, DiscardOldestPolicy, and DiscardPolicy—detailing their behavior, suitable scenarios, and providing full code examples, plus guidance on creating custom policies.
LiteFlow is a lightweight Java rule engine that lets developers orchestrate serial and parallel business workflows using XML, JSON or YAML rule files stored in back‑ends like SQL or Zookeeper, offering NodeComponent, NodeSwitchComponent and NodeIfComponent types, EL syntax, Spring Boot integration, and high‑performance execution monitoring.
This article explains the Chain of Responsibility design pattern, its core concepts, characteristics, and problems it solves, then demonstrates how to combine it with the Strategy pattern through detailed Java code examples that illustrate a product‑up‑shelf validation workflow and a generic request‑handling scenario.
This guide walks you through installing Spring Boot CLI, explains its Groovy‑based features, demonstrates creating and running a Hello World web app, shows how to use @Grab for dependencies, test with spring test, package into executable JARs, and explore init and shell commands.
This guide explains Apache RocketMQ’s ordinary message concept, its full lifecycle, how to create topics, Java code for sending and receiving messages, key configuration tips, and real‑world scenarios such as asynchronous decoupling and traffic‑shaping for micro‑service architectures.
This article explains how to track online users by storing their identifiers in a Redis sorted set, using expiration timestamps as scores, and demonstrates adding, querying, and cleaning up entries with ZADD, ZRANGEBYSCORE, ZREMRANGEBYSCORE, and ZREM commands in both Java and JavaScript.
This article investigates the detailed steps and time consumption of establishing and closing a MySQL connection from a Java web application, using Wireshark packet captures and code examples to demonstrate why connection pooling is essential for high‑traffic services.
This article explains Java's ThreadLocal mechanism, detailing its internal ThreadLocalMap structure, core set/get/remove operations with full code examples, and demonstrates how multiple ThreadLocal variables are stored per thread, providing a clear understanding of thread‑local storage in backend development.
This article explains how to build a flexible, scalable permission control system in Java using custom annotations and Spring AOP, covering basic concepts, system requirements analysis, database schema design, annotation definitions, aspect implementation, and business logic services for comprehensive access management.
DynamicTp is a Java‑based dynamic thread‑pool framework that extends ThreadPoolExecutor to enable runtime parameter tuning, real‑time monitoring, and multi‑channel alerting, addressing common pain points of thread‑pool configuration in microservice environments.
The article first shares a personal anecdote about job background checks and then presents a detailed explanation of LeetCode problem 5 – Longest Palindromic Substring – including problem description, dynamic‑programming analysis, recurrence formula, and complete Java and C++ code examples.
This article presents a comprehensive collection of written‑test and interview questions covering Java basics, Spring MVC annotations, JVM memory, garbage collection, database design, transaction management, distributed systems, version control, and development workflow, aimed at helping candidates prepare for small‑company technical interviews.
This article presents LiteFlow, a lightweight yet powerful rule engine built on Spring Boot, explains its architecture, component types, EL rule file syntax, data context handling, configuration options, and demonstrates a practical e‑commerce workflow example with full code snippets and deployment tips.
This tutorial explains how to create a traffic sign recognition application using Spring Boot and Java Deeplearning4j, covering CNN selection, dataset organization, Maven dependencies, data loading, model construction, training, prediction, unit testing, and expected results.
This article explains the background, challenges, and recursive algorithmic solution JD Logistics uses to merge purchase orders, detailing the merging rules, code implementation, deduplication strategy, performance gains, and the resulting operational benefits such as increased merchant satisfaction and faster processing.
This article introduces the URule rule engine, explains its core concepts and library types, shows how to install and configure it within a Spring Boot project, demonstrates rule set and decision‑table creation, and provides complete Java code examples for practical usage.
This guide shows how to integrate the Drools rule engine into a Spring Boot application to calculate e‑commerce discounts dynamically, covering Maven dependencies, configuration, model definitions, DRL rule creation, service and controller layers, and a simple test scenario demonstrating rule‑driven discount computation.
This article explains the core concepts of Java’s AbstractQueuedSynchronizer (AQS), its exclusive and shared modes, the template‑method design it uses, and walks through the actual source code showing how ReentrantLock implements both fair and non‑fair locking, complete with diagrams and code snippets for interview preparation.
This article introduces a Spring Boot 3 case collection and details five practical methods—URL path, request parameter, request header, Accept header, and custom annotation—to implement API version control, complete with code examples and guidance for maintaining compatibility across multiple API versions.
This article explains how Java's volatile keyword provides visibility guarantees and prevents instruction reordering through memory barriers, illustrates its behavior with code examples, discusses its limitations regarding atomicity, and outlines appropriate usage scenarios such as state flags and double‑checked locking.
This article explains Java’s java.util.concurrent.Phaser class, compares it with CountDownLatch, details its core methods, demonstrates practical usage with code examples, and shows how to build a custom lightweight synchronization utility for performance testing scenarios.
This article walks through a real‑world case of importing over 60,000 XML rows into MySQL, profiling the initial 300‑second runtime, and applying a series of optimizations—including JDBC batch processing, rewriteBatchedStatements, multithreaded asynchronous writes with Disruptor, and MySQL tuning—to achieve a final import time of around 4 seconds while managing memory usage.
This article demonstrates a practical approach to protect sensitive Spring Boot applications by encrypting the JAR with AES, storing the key in a secure vault, and using a custom ClassLoader to decrypt and load classes at runtime, while highlighting key management, performance, and additional hardening considerations.
This article introduces magic-api, a Java‑based rapid development framework that lets developers create HTTP APIs without writing traditional Controllers, Services, or DAOs, and provides a UI for designing endpoints, extensive database support, clustering, Swagger integration, and a quick‑start guide with Maven and configuration examples.
This article explains the step‑by‑step decision process a Java thread pool follows when execute() adds a task, covering core and maximum pool sizes, queue handling, thread creation, rejection policies, and idle thread termination.
This article introduces the Liteflow rule engine, explains its architecture and supported file formats, demonstrates how to configure and use it with Spring Boot, details component types and EL rule files, and showcases a practical e‑commerce workflow example with code snippets.
This article explains how Redisson leverages Redis, Lua scripts, and Pub/Sub to implement a robust distributed lock in Java, covering lock characteristics, client creation, acquisition, renewal, and release mechanisms with code examples.
The article explains the true purpose of the Linux kill command, compares signals like SIGTERM and SIGKILL, warns about the dangers of force‑killing processes, and provides practical Java shutdown‑hook examples and a shell script for safe, graceful termination.
This article breaks down the seven parameters of Java's ThreadPoolExecutor constructor, explaining corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory, and handler, and provides practical tips on thread creation and rejection policies.
The article presents a step‑by‑step guide to refactor Spring MVC controller code by unifying response formats, applying a global response wrapper, enforcing parameter validation with JSR‑303, and handling custom exceptions through a centralized advice, all illustrated with complete Java examples.
This article explains how to protect time‑consuming business operations and critical data by designing a Redis‑based distributed lock using custom annotations, Spring AOP, and a ScheduledExecutorService that automatically extends the lock’s expiration to avoid premature release.
This article reviews the most popular programming languages that can serve as alternatives to PHP for web development, evaluating each option’s performance, ecosystem, and suitability for server‑side projects, and offers guidance on selecting the best replacement based on project requirements.
The article reviews a Java veteran's 20‑year experience to identify backend technologies such as JSP, Struts, Hibernate, Servlet, Applet, Swing, JDBC and XML that are now outdated or less essential, and recommends focusing on Spring MVC, MyBatis and a deep understanding of Servlets for modern development.
CountDownLatch and CyclicBarrier are two essential Java synchronization tools from java.util.concurrent, enabling threads to coordinate tasks; this guide explains their concepts, usage with code examples, advantages, disadvantages, and key differences, helping developers choose the right tool for thread coordination.
Learn how to integrate Go and Java by compiling Go code into a shared library, exposing functions via cgo and JNI, and invoking them from Java with detailed setup, code examples, handling of primitive and complex data types, and full build‑and‑run instructions.
This article provides a comprehensive technical walkthrough of the Druid database connection pool, covering its architecture, initialization flow, connection acquisition and release mechanisms, execution and exception handling, as well as recommended configurations and monitoring practices for optimal performance.
This article provides a step‑by‑step tutorial for Java engineers on using the LangChain4j framework to implement Retrieval‑Augmented Generation (RAG) with large language models, covering concepts, environment setup, code integration, document splitting, embedding, vector‑store operations, and prompt engineering.
This article walks Java developers through the fundamentals of Retrieval‑Augmented Generation (RAG), explains the LangChain4j framework, compares large‑model development with traditional Java coding, and provides step‑by‑step code examples for environment setup, document splitting, embedding, vector‑store operations, and LLM interaction.
This article explains Netty's powerful asynchronous architecture, compares classic multithread, Reactor, select, poll, and epoll I/O multiplexing models, demonstrates JNI integration for native performance, and provides complete example code for building a high‑performance epoll‑based server in Java.
This article explains the purpose, basic methods, best‑practice usage, and typical scenarios of Java's CountDownLatch utility, providing code examples and a comparison with Thread.sleep to help developers synchronize multiple threads effectively.
This article explores Java's thread communication techniques—including the basic wait/notify mechanism, advanced Lock and Condition usage, and the thread‑safe BlockingQueue—providing detailed explanations, producer‑consumer examples, and additional concurrency utilities like CountDownLatch, illustrating how to coordinate threads efficiently in multithreaded applications.
This article explains how to use Maven plugins to build a Spring Boot project into an executable JAR, separate its dependencies into a lib folder, and create a Docker image that copies those libraries, enabling clean deployment of Java backend services.
The article proposes a domain‑model‑driven code paradigm—defining clear business models, core domain objects, and infrastructure abstractions like repositories, facades, and factories—while contrasting it with process‑driven designs using ability nodes and chains, arguing that these patterns cut repetitive effort and boost maintainability.
This guide explains why Tomcat's default development settings need tuning for production, covering JVM memory model basics, configuration file edits, thread pool and connector adjustments, as well as security hardening steps to improve performance and stability.
In its 2024 year‑end review, vivo Internet Technology published 44 technical articles, delivered 19 presentations on cloud‑native, AI, security and more, joined major open‑source foundations such as Linux, CNCF and CCF, and grew a community of over 70,000 technical professionals.
This article explains how to build a Spring Boot service that preprocesses images with OpenCV, extracts text using Tesseract OCR, and then parses identification numbers such as ID cards and business licenses via regular expressions, providing complete code examples and dependency details.
This article explains how to query multiple identical databases under a single data source by intercepting MyBatis SqlSource, using JSqlParser to prepend the appropriate database name to table references, and applying the decorator pattern for seamless dynamic database switching.
This article explains how to create a custom annotation and a MyBatis‑Plus interceptor that automatically injects data‑permission SQL conditions based on the current user's role, showing both a basic implementation and an advanced version with role‑based scope handling, complete with code examples and integration steps.
From Smalltalk’s pioneering pure‑object orientation, through Strongtalk’s static typing and Sun’s HotSpot JVM, to Lars Bak’s V8 JavaScript engine and the subsequent Dart language, a handful of innovators—including Gilad Bracha, Urs Hölzle, and Bak himself—have continually reshaped virtual‑machine performance and modern programming ecosystems.
This article explains why Spring Framework discourages field injection with @Autowired, compares constructor, setter, and field injection types, provides code examples for each, and discusses the drawbacks of field injection such as immutability issues, violation of single‑responsibility principle, tight coupling to the container, and hidden dependencies.
This article explains how to print numbers from 1 to 100 with two Java threads—one handling odd numbers and the other even numbers—by first using a synchronized block with wait/notify and then by employing Semaphore for thread coordination.
DynamicTp extends Java's ThreadPoolExecutor with zero‑intrusion configuration, real‑time parameter adjustment, comprehensive monitoring, and multi‑channel alerting, allowing developers to dynamically tune thread pools across microservices using popular configuration centers and integrate with tools like Micrometer and Grafana.
This article explains the purpose and usage of Java’s synchronized keyword, covering object locks, method locks, synchronized blocks, and class locks, along with detailed code examples that demonstrate how threads acquire and release locks to ensure data consistency in multithreaded environments.
In Java’s ThreadPoolExecutor, core threads remain alive even when idle unless the allowCoreThreadTimeOut flag is set to true, which then permits both core and non‑core threads to be reclaimed after exceeding the keepAliveTime threshold, a behavior that contradicts the pool’s design principle of minimizing thread creation overhead.
This article explores the One Billion Row Challenge, a Java benchmark that requires parsing a 13 GB file of one billion temperature records, and walks through baseline code, top‑ranked solutions, and a step‑by‑step performance tuning journey that reduces execution time from minutes to under two seconds.
The article explains why using Thread.sleep in a loop causes busy‑waiting and performance problems, and demonstrates several Java scheduling alternatives—including Timer/TimerTask, ScheduledExecutorService, wait/notify, and CompletableFuture—to efficiently check a flag at fixed intervals.
This article introduces the evolution of Java workflow engines, explains core BPMN concepts, and provides a comprehensive tutorial on integrating Flowable with Spring Boot—including Maven dependencies, database configuration, BPMN diagram creation, service task implementation, diagram viewing API, and unit testing.
Spring Boot enables modular backend development by placing each feature in its own Maven module and using @Import (or custom annotations, ImportSelector, ImportBeanDefinitionRegistrar, and @ConditionalOnProperty) to load configuration classes, scan components, and conditionally register beans while keeping the application a single monolithic program.
This article explains Spring Boot’s asynchronous processing mechanism, covering its purpose, the @Async annotation, configuration steps, custom thread pool setup, handling return values, and typical use cases, enabling developers to improve performance and responsiveness in backend applications.
This article examines why many large‑scale systems avoid the traditional delayed double‑delete cache‑invalidation strategy, explains its critical drawbacks, and presents alternative lease‑based and version‑based approaches with Lua scripts and Java wrappers for Redis to achieve stronger consistency.
This article introduces Apache Commons Lang 3, explains its key utilities, and demonstrates how to integrate the library with Maven and employ DiffBuilder and ReflectionDiffBuilder to compare Java objects, generate detailed difference reports, and simplify debugging and testing processes.
This guide explains how to efficiently and elegantly handle null pointer checks in Java by identifying data types, selecting the right utility classes such as StringUtils, ObjectUtils, Arrays, Collections, and applying their isEmpty methods to reduce repetitive code.
Explore the contrast between declarative and imperative programming, dive into Java Stream fundamentals, benchmark parallel versus sequential execution, and understand the role of annotations, offering practical insights for writing cleaner, more efficient backend code.
This article explains why plugin mechanisms improve modularity, extensibility, and third‑party integration, then walks through practical Java SPI implementations, custom configuration loading, and Spring Boot’s spring.factories approach, providing complete code examples and step‑by‑step guidance for building a robust plugin system.
The article surveys popular Java expression engines—including Spring Expression Language, OGNL, Aviator, and MVEL2—detailing their key features and providing lightweight utility wrappers, and highlights Hutool’s unified façade that can encapsulate these engines to simplify dynamic rule evaluation in backend applications.
This article explains how to improve performance of massive IN‑list queries in PostgreSQL by splitting the parameter list, executing the sub‑queries concurrently with a custom Spring AOP annotation, and merging the results using a configurable thread pool and return‑handling strategy.
This article explains how to improve performance of massive IN‑list queries in PostgreSQL by splitting the list, executing sub‑queries in parallel using a custom Spring AOP annotation, and merging the results with a configurable handler, providing a reusable solution for Java backend services.
This article presents ten practical MyBatis techniques—including dynamic SQL, resultMap, foreach, pagination, annotation proxies, second‑level cache, dynamic table names, custom type handlers, logging, and multi‑datasource configuration—to help Java developers write cleaner, safer, and more performant data‑access code.
This article breaks down Java's three memory regions—Heap, Off‑Heap, and No‑Heap—detailing their definitions, management mechanisms, performance impacts, typical use cases, and provides concrete code samples for allocating each type of memory.
This article explains why thread execution order is nondeterministic and presents eight Java techniques—join, single‑thread executor, CountDownLatch, CyclicBarrier, Semaphore, synchronized with wait/notify, and Lock with Condition—to reliably enforce sequential execution, complete with clear code examples for each method.
Java developers can parse JSON using six popular approaches—Jackson for high‑performance, annotation‑driven serialization; Gson for a lightweight, easy‑to‑use API; FastJSON for speed; JsonPath for XPath‑style nested extraction; org.json for simple utility; or manual parsing for full control—each suited to different performance and complexity needs.
This article explains how to integrate Spring Boot with MyBatis, configure a single Druid data source, implement a dynamic routing data source for multiple databases, and use custom annotations and AOP to switch databases at runtime, including full code examples and transaction management.
This article introduces and compares several Java expression engines—including Spring Expression Language, OGNL, Aviator, MVEL, and Hutool's expression facade—detailing their key features, typical use cases, security considerations, and providing utility class examples with code snippets for each engine.
This article provides a step‑by‑step tutorial on using Maven for Java backend projects, covering repository configuration, basic POM structure, dependency declaration, scope handling, exclusion, variable properties, multi‑module management, dependencyManagement, and common build plugins such as jar, assembly, and shade.
This article explains what Java enums are, why they are preferable to constants, demonstrates basic and custom enum definitions, shows how to compare, switch, and extend enums with properties, methods and constructors, and explores advanced uses such as EnumSet, EnumMap, Singleton and Strategy patterns, including Java 8 stream examples and JSON serialization.
This article introduces Java 8's Optional class as a robust solution for avoiding NullPointerException, explains its creation methods, demonstrates common operations such as get, isPresent, ifPresent, filter, map, flatMap, orElse, orElseGet, orElseThrow, and provides practical usage scenarios and cautions for developers.
This article describes how a legacy SSM‑based backend reporting service was refactored by archiving log data, leveraging Redis for hourly counters, and scheduling synchronization tasks to dramatically reduce query time for millions of records without adding external processing frameworks.
The article explains that in Java's SimpleDateFormat the lowercase y pattern (year‑of‑era) should be used for calendar dates, because the uppercase Y pattern represents a week‑based year which can incorrectly roll over to the next year near year‑end, causing bugs.
This article explains how to handle massive Excel‑DB import/export tasks in Java by comparing POI workbook types, selecting the right implementation, and leveraging EasyExcel with batch queries, sheet splitting, and JDBC batch inserts to process over three million rows efficiently.
This article introduces Java's java.util.concurrent.atomic package, detailing the core atomic classes—AtomicBoolean, AtomicInteger, AtomicLong, and LongAdder—including their constructors, key methods, typical use cases, and performance considerations in high‑concurrency scenarios for developers seeking efficient thread‑safe operations.
This article explains the Fork/Join model and ForkJoinPool in Java, covering divide‑and‑conquer theory, RecursiveTask implementation, task submission methods, work‑stealing queues, common pool pitfalls, and performance testing with code examples to help developers choose and tune parallel execution strategies.
This article presents a comprehensive guide to Spring's utility classes—including Assert, ObjectUtils, StringUtils, CollectionUtils, FileCopyUtils, ResourceUtils, StreamUtils, ReflectionUtils, and AOP helpers—detailing their purpose, usage patterns, and code examples, while also containing promotional material for related services.
Beyond the JDK, modern Java backend development relies on a core toolkit—including SpringBoot, Netty, Guava or Hutool utilities, JUnit 5 with Mockito, JMH, OkHTTP, HikariCP or Druid pools, Caffeine cache, Hazelcast, SLF4J + Logback, Jackson, Jolokia, Hibernate‑Validator, and FreeMarker—to build robust, high‑performance enterprise services.
This article introduces several Chinese open‑source AI platforms, shows how to import their Java SDKs, obtain API keys, run test demos, encapsulate a reusable AI module with Spring Boot configuration, and apply prompt‑engineering techniques to generate AI‑driven questionnaire content.
This article explains Java virtual threads, compares them with regular threads, shows how to enable them in SpringBoot, and presents performance tests that reveal up to a 200‑fold reduction in latency for IO‑bound workloads.
This article explains why Java's BigDecimal can guarantee lossless precision in financial calculations by examining its class definition, internal fields, example usage, and the detailed implementation of its add method, including scaling and long‑integer arithmetic.
This article compares six popular Java JSON parsing approaches—Jackson, Gson, FastJSON, JsonPath, org.json, and manual parsing—detailing their features, code samples, advanced options, and pros and cons to help developers choose the right tool for their projects.
This article explains how Java HotSpot uses a card‑table memory set to efficiently detect and handle cross‑generational references during young‑generation GCRoot scans, avoiding full old‑generation scans and significantly improving garbage‑collection performance.
This article explains six typical techniques—@RequestParam, @PathVariable, @MatrixVariable, @RequestBody, @RequestHeader, and @CookieValue—for extracting request data in Spring Boot APIs, providing usage scenarios and concrete code examples for each method.
To remediate CVE‑2023‑6378 in a Spring Boot 2.7.x application, you must replace the default logging starter with a direct Logback 1.2.x dependency (e.g., 1.2.13), because Spring Boot 2.7 cannot use Logback 1.3.x due to the removed StaticLoggerBinder class; the only other option is to upgrade the whole stack to Spring Boot 3.x, Logback 1.4.x, and JDK 11.
This article explains the challenges of thread synchronization in distributed systems, introduces the concept of distributed locks, compares common implementations such as Redis, Zookeeper, and databases, and provides robust Java and Lua solutions to ensure atomicity, avoid deadlocks, and support lock renewal.
Spring Boot 3.4 introduces extensive updates—including RestClient and RestTemplate auto‑configuration, revised HTTP client factories, refined bean validation, graceful shutdown defaults, a new Paketo tiny builder for OCI images, deprecations, and numerous configuration and observability enhancements—providing developers with a comprehensive guide to upgrade and leverage the latest features.
This article presents a curated list of 31 IntelliJ IDEA plugins—including translation tools, language packs, UI themes, code navigation, version control, code quality, and productivity enhancers—that together streamline Java backend development and improve developer efficiency.
This article explains various plugin implementation approaches in Java, including SPI, ServiceLoader, custom configuration, and Spring Boot's spring.factories, providing detailed code examples and step‑by‑step guidance for building extensible backend systems that can be dynamically loaded and configured at runtime.
This article explains how to prevent duplicate data submissions in a Spring Boot application by designing an idempotent mechanism using AOP and Redis, covering the concept, design strategy, custom annotation, aspect implementation, and a simple test controller.
The 2024 Java trend report analyzes JDK adoption rates, AI tooling, the rise of the Commonhaus Foundation, Spring and Jakarta EE evolution, virtual thread adoption, and community insights, offering guidance for technical leaders and developers planning their future investments.
This article explores the role of WebSocket in IoT, detailing its advantages over HTTP, comparing Java implementations, presenting a Netty‑based architecture for smart devices, and providing complete code examples for connection handling, authentication, and message processing to achieve real‑time communication.
