This article explains why Spring Boot 3 uses Jackson for JSON handling, describes four effective methods—JsonNode, Map, @JsonAnySetter, and custom deserializer—to process dynamic JSON properties, and promotes a continuously updated collection of over 90 Spring Boot case studies with source code.
This article provides a step‑by‑step tutorial on integrating the Flowable BPMN workflow engine into a Spring Boot application, covering dependencies, BPMN diagram creation, task configuration, service implementation, process visualization, and common pitfalls such as font issues and process definition updates.
This guide shows how to implement dynamic MySQL master‑slave switching in a SpringBoot 3 project using AOP and a custom @DataSource annotation, configuring Druid pools, defining a routing datasource, and automatically falling back to the master when a slave fails for high availability.
This article explains the Facade design pattern, its purpose of simplifying complex systems, outlines its benefits and UML structure, and demonstrates a complete Spring Boot example that encapsulates flight, hotel, and package services behind a BookingFacade for a travel‑booking application.
This article explains how to improve performance of massive IN‑list database queries in Java by defining custom Spring AOP annotations that automatically split the parameter list, execute the sub‑queries concurrently in a thread pool, and merge the results using a configurable return‑handling strategy.
This article explains the Java Virtual Machine's two subsystems—Class Loader and Execution Engine—and its two main components—Runtime Data Area and Native Interface—detailing their functions, internal structures, and the overall execution workflow of Java programs.
This article explains how to select and customize a Java thread pool for performance testing, covering parameter considerations, modifications to the standard fixed thread pool, custom thread factories, work queue choices, and provides complete example code for both fixed and TPS models.
Explore how Spring Boot 3 leverages the @ExceptionHandler annotation to centralize error handling, customize responses based on the Accept header, configure view beans for HTML errors, and utilize new Spring 6.2 attributes, with complete code examples and testing guidance.
When a Linux server's CPU spikes to 100%, this guide walks you through a systematic investigation—from identifying the high‑load process and pinpointing the offending Java thread to applying a streamlined shell script—so you can resolve the issue and restore normal performance.
By combining EasyExcel’s low‑memory parsing with Java 8 functional style, reflection‑based generic annotations, a thread‑pool‑driven batch listener, and flexible export utilities that support dynamic headers and map‑based rows, Java back‑ends can safely import and export millions of Excel rows without OOM errors.
Java 24, a short‑term JDK release slated for March 2025, introduces 24 new features—including two experimental JEPs, one incubator JEP, seven preview JEPs, and fourteen permanent JEPs—while outlining Oracle’s roadmap toward the subsequent long‑term Java 25 version.
This guide details how to integrate WeChat native payment into a Java backend, covering merchant setup, Spring configuration, QR‑code generation with the official SDK, handling HTTPS callbacks, and implementing front‑end polling using Redis and Bloom filters for reliable membership upgrades.
The Next Permutation problem asks to rearrange an integer array into the immediate lexicographically larger ordering—or the smallest order if none exists—by scanning from the right to find the first decreasing pair, swapping with the next larger element, and reversing the suffix, using O(1) extra space, with implementations provided in Java, C++, and Python.
This article introduces the lightweight Sa-Token Java authentication framework, explains why it is chosen over Spring Security and Shiro, details its login and permission APIs with code examples, shows how to configure it in Spring Boot and WebFlux projects, and lists its extensive feature set for secure backend development.
This article explains Java's reflection mechanisms, comparing Class.forName and ClassLoader as two primary ways to load classes, detailing their behavior, static initialization effects, code examples, and practical scenarios such as loading JDBC drivers versus custom dynamic loading.
MapStruct is a compile‑time Java annotation processor that automates bean mapping, offering concise, high‑performance, type‑safe conversions, and advanced features such as expression mapping, qualifiedByName methods, null‑value strategies, and decorators, with full IDE support and illustrative code examples.
The Spring Boot starter automatically registers XXL‑Job executors and job handlers at application startup by logging into the admin console, scanning beans for methods annotated with @XxlJob and @XxlRegister, and invoking the admin APIs to create missing groups and jobs, eliminating manual configuration.
This article introduces the QLExpress rule engine, outlines its key features such as thread‑safety and high‑performance execution, and provides step‑by‑step Spring Boot 3 integration examples—including dependency setup, simple expressions, function definitions, operator aliases, macro usage, and variable querying—complete with runnable code snippets and output illustrations.
This article reviews Java Spring code for a coupon claim and approval workflow, identifies concurrency and transaction issues such as missing locks and inconsistent update order, and proposes optimizations including user‑level locking, simplifying lock management, and aligning transactional update sequences to prevent deadlocks.
By switching from a naïve per‑record insert to JDBC batch writes with rewriteBatchedStatements and then off‑loading those batches to multiple consumer threads via a LMAX Disruptor ring buffer, the XML‑to‑MySQL import of 60,000 rows dropped from roughly 300 seconds to about 4 seconds while keeping memory usage modest.
This article introduces UniHttp, a declarative Java HTTP client framework that simplifies third‑party API integration by using annotations to generate request metadata, supports various parameter types, lifecycle hooks, custom processors, and provides practical enterprise‑level examples with full code snippets.
This article compares three Java concurrency approaches—Future with Callable, CompletableFuture, and FutureTask—explaining their underlying principles, step‑by‑step usage, code examples, and trade‑offs so you can decide which asynchronous tool best fits your reporting workload.
To avoid the O(n × m) cost of naïve nested loops when matching IDs, replace the inner scan with a break after a unique match or, far more efficiently, build a HashMap of the secondary list so each lookup becomes O(1), dropping overall complexity to O(n + m) and cutting execution time from tens of seconds to a few hundred milliseconds.
This article describes an experiment using SpringBoot 2.5.4 and JMeter to measure the heap memory allocated per HTTP and RPC request, detailing the setup, GC logging configuration, results showing average memory consumption around 34 KB per request, and recommendations for logging and performance optimization.
Java 21’s virtual threads provide a lightweight, JVM‑managed alternative to OS threads that enables hundreds of thousands of concurrent tasks, simplifies scheduling, integrates easily into Spring Boot via a preview flag and Tomcat executor, and delivers up to five‑fold speed‑ups and lower latency in high‑load I/O‑intensive applications.
This article presents seven practical methods for recording API request logs in Spring Boot 3, including Filter, HandlerInterceptor, AOP, event listeners, Logbook, custom HandlerMethod, and RestTemplate/RestClient interceptors, complete with code samples, configuration steps, and execution screenshots.
This article presents fifteen useful Spring techniques—including bean retrieval, event handling, custom interceptors, retry mechanisms, global exception handling, startup initialization, bean lifecycle methods, resource cleanup, dynamic configuration injection, conditional bean registration, caching, transaction management, bean loading order, AOP aspects, and conditional bean creation—each illustrated with clear Java code examples.
This article lists eight common beginner programming mistakes—from using wrong punctuation and forgetting WHERE clauses to leaking resources, storing passwords in plain text, exposing API keys, mixing environments, force‑pushing code, and committing secrets—explaining why they happen, showing concrete code examples, and offering practical fixes.
This article walks through a systematic, eight‑step approach to sizing and configuring JVM memory parameters—including heap, young generation, stack, object age thresholds, and garbage‑collector selection—so that a service handling one million daily logins on an 8 GB machine can achieve stable performance and predictable GC behavior.
This tutorial explains how to combine Spring Boot and Redis using Lua scripts, covering Lua fundamentals, performance advantages, practical use cases, step‑by‑step implementation in Spring Boot, error handling, security considerations, and best‑practice recommendations for backend developers.
This article explains common interview questions on frequent Full GC and high CPU usage in Java backend development, detailing root causes, JVM parameter adjustments, memory leak prevention, and code optimization techniques, along with practical code examples and tool recommendations for effective performance tuning.
LeetCode 57 asks you to insert a new interval into a sorted list of non‑overlapping intervals, merging any overlaps so the result stays sorted and disjoint, and the article explains the O(n) algorithm and provides concise implementations in Java, C++ and Python.
This article presents twelve practical MyBatisPlus optimization techniques—including avoiding isNull, specifying select fields, batch operations, using EXISTS, safe ordering, LambdaQuery, between, index‑aware sorting, pagination, null‑handling, performance tracking, enum mapping, logical deletion, and optimistic locking—to help Java developers write cleaner, more efficient backend code.
This article explains common CPU and JVM memory bottlenecks in Java applications, shows how to detect abnormal usage with monitoring and alerts, and provides step‑by‑step methods—including top, jstack, flame‑graph analysis, and APM tools—to pinpoint and resolve performance hotspots efficiently.
This article systematically explains the importance of rate limiting in microservice systems, compares various governance frameworks such as Dubbo and Spring Cloud, introduces common algorithms like token‑bucket and leaky‑bucket, and provides detailed implementation examples using Guava, Sentinel, Redis+Lua, and a custom Spring Boot starter.
This article introduces MapStruct, a compile‑time Java bean mapping framework, and demonstrates advanced features such as expression‑based mappings, qualifiedByName custom converters, nullValueMappingStrategy handling, and decorator‑based post‑processing with concrete code examples for Spring‑based projects.
This article introduces the LiteFlow rule engine, explaining its architecture, supported rule file formats, component types, EL rule definitions, data context handling, configuration options, and demonstrates its application in an e‑commerce order processing scenario, highlighting hot‑deployment and performance benefits for Java backend development.
This article details a Java GC optimization performed on a nightly batch service, describing the original high GC and CPU load issues, the JVM parameter adjustments, memory re‑allocation, and the resulting significant reductions in GC frequency, CPU usage, and request latency.
This article explores practical HTTP retry solutions for offline store applications, covering a basic loop retry, the built‑in retry mechanism of Apache HttpClient with custom handlers, and an asynchronous retry approach using message queues to achieve higher reliability and eventual consistency.
This article explains how to use Spring Boot's @Import annotation to modularize applications, add scanning entry points, and dynamically register beans via ImportSelector and ImportBeanDefinitionRegistrar, including code examples and configuration tips for Maven multi‑module projects.
This article announces a Spring Boot 3 practical case collection and provides a comprehensive Flyway tutorial—including installation, configuration, migration scripts, multi‑datasource usage, and visual verification—so developers can confidently manage database schema changes in Java backend projects.
This article explains the concepts, lifecycle methods, and configuration of Spring Boot's Filter, Interceptor, and AOP mechanisms, compares their execution order, and shows code examples to help developers choose the right technique for adding cross‑cutting functionality without altering core business logic.
This article explains the stateless nature of HTTP, compares session‑based and token‑based authentication, describes JWT structure and security considerations, and provides Java code examples for implementing login, token generation, verification, and extraction in a backend application.
This comprehensive guide introduces Java's CompletableFuture, explains its advantages over the traditional Future API, demonstrates how to create and compose asynchronous tasks, manage thread pools, handle timeouts and cancellations, and apply robust exception handling techniques for reliable concurrent programming.
This article deep‑dives into Spring Boot’s inner workings, explaining why dependency versions are omitted, how the spring‑boot‑starter‑parent and spring‑boot‑dependencies manage libraries, and how the composite @SpringBootApplication annotation orchestrates @SpringBootConfiguration, @EnableAutoConfiguration, and @ComponentScan to achieve seamless auto‑configuration and rapid application startup.
FastExcel is a Java library that builds on EasyExcel to provide higher performance, low‑memory streaming, and additional features such as PDF conversion, offering simple APIs, full compatibility, and detailed code examples for creating entity classes, listeners, and read/write operations.
This article walks you through configuring Spring Cloud for dynamic property updates, covering dependency setup, enabling bootstrap, defining configuration properties, exposing a refresh endpoint, and listening to EnvironmentChangeEvent, all illustrated with complete code snippets and screenshots.
This guide presents a comprehensive set of practical strategies—including batch processing, asynchronous execution, caching, pre‑processing, pooling, parallelization, indexing, transaction sizing, program refactoring, pagination, SQL tuning, and lock granularity—to dramatically reduce API latency in Java backend services.
This article explains how to improve backend performance by fetching independent report data concurrently using Java's Future, Callable, CompletableFuture, and FutureTask classes, provides code examples for each approach, and compares their principles, usage patterns, and cancellation capabilities.
This article demonstrates how to add Apache Tika dependencies to a Spring Boot project, configure tika-config.xml, create a Java configuration class, and use the injected Tika bean to detect, translate, and parse various document formats such as PDF, PPT, and XLS.
This article compares Java's built‑in synchronized keyword with the explicit ReentrantLock class, covering their underlying implementations, performance differences across JDK versions, feature sets such as fairness and interruptibility, lock release mechanisms, and best‑fit scenarios for each approach.
This article explores common overselling problems in high‑concurrency flash‑sale scenarios and presents seven practical solutions—including lock timing adjustments, AOP locking, pessimistic and optimistic database locks, and queue‑based approaches—each illustrated with SpringBoot code and performance test results.
This chapter explains how to build a Java-based performance testing engine by dissecting common testing requirements, illustrating queue and throttling models through a supermarket analogy, and presenting thread‑based and TPS‑based designs with code examples and future extensions.
The article explains the DDD rich (or active) model, its core characteristics, compares it with the anemic model, and shows how to apply it in a shared‑rental billing domain using Java, DDD layers, domain events, and a lightweight framework.
This article presents a comprehensive design for securing third‑party API calls by generating unique Access Key/Secret Key pairs, defining permission granularity, implementing signature generation with timestamps and nonces, handling token lifecycle, and providing concrete Java and SQL code examples for practical deployment.
This article explains the concept of plugin mechanisms in Java and Spring Boot, covering benefits, common implementation approaches such as ServiceLoader and custom configuration, detailed code examples, and practical guidance for building extensible backend systems.
This article explains three backend solutions—database polling with scheduled tasks, JDK DelayQueue, and Netty's HashedWheelTimer—for automatically cancelling unpaid orders after a timeout in a monolithic architecture, detailing their implementation steps, pros, cons, and optimization tips with Java code examples.
This article documents a step‑by‑step investigation of a Java 11 application that suffered OS‑level OOM despite a 4 GB heap, revealing that multiple Netty PooledByteBufAllocator instances loaded by different class loaders consumed far more native memory than expected.
This article demonstrates how to integrate the open‑source Sensitive‑Word Java library via Maven, showcases core find/replace methods, explains advanced detection features such as email, URL, IP and numeric filtering, and provides a custom replacement strategy with complete code examples.
The article analyzes the role of Spring MVC Controllers, identifies issues with traditional implementations, and demonstrates how to create a unified response structure, automatically wrap results using ResponseBodyAdvice, resolve String conversion problems, and apply JSR‑303 validation with custom rules and global exception handling.
A recent migration exposed severe latency on certain Kubernetes pods, traced to Redis connection‑pool misconfigurations and validation locks, with detailed packet captures, ARMS code‑hotspot analysis, and step‑by‑step fixes that restored performance across the cloud‑native environment.
This tutorial demonstrates how to build a Spring Boot application that extracts ID numbers and business license information from images by preprocessing them with OpenCV and recognizing text with Tesseract OCR, covering the full workflow from image handling to regex-based data extraction.
The article introduces DynamicTp, a SpringBoot-based dynamic thread‑pool framework that enables real‑time adjustment, monitoring, and alerting of ThreadPoolExecutor parameters via various configuration centers, outlines its architecture, modules, features, and integration with third‑party components, and provides usage guidance for Java backend developers.
This guide explains how to configure Alipay sandbox credentials, expose a local Java Spring Boot service via a tunneling tool, add the Alipay SDK dependency, set up configuration files, implement payment and notification endpoints, and handle common initialization errors for seamless backend payment integration.
This article explains what unfair locks are, why they can improve throughput compared to fair locks, provides a Java ReentrantLock example with code, describes the internal acquisition process, and outlines typical high‑concurrency scenarios where unfair locks are advantageous.
This article introduces a concise and elegant Java TimeTracker utility class that leverages AutoCloseable, try‑with‑resources, and functional interfaces to provide flexible performance monitoring, automatic duration calculation, and configurable exception handling while reducing repetitive timing code.
The author recounts a two‑day investigation of a widespread FastJson failure caused by a Kotlin lambda mistakenly assigned to an Object field, detailing the mixed‑language project background, the puzzling symptoms, step‑by‑step debugging, the root‑cause analysis, and the final resolution.
This article introduces LiteFlow, a lightweight Java component‑based rule engine that decouples complex business logic, explains its workbench design, demonstrates usage in both non‑Spring and SpringBoot environments with Maven setup and XML configuration, and details its core components, parsing, chain execution, and node processing.
This article explains the fundamental differences between stack and heap memory, covering their structures, allocation strategies, performance characteristics, language-specific examples in Java, C++, and Python, and provides guidance on when to use each type for efficient programming.
This article recounts a production incident where Spring Boot services consumed excessive memory, explains how to diagnose the issue using jps and jmap, discusses default JVM heap settings, offers practical remediation steps, and also contains promotional material for AI community services and related offers.
This article clarifies the differences among Java’s thread interruption methods—interrupt(), Thread.interrupted(), and isInterrupted()—explaining how each affects a thread’s interrupt status, when exceptions are thrown, and how to properly monitor and handle interruptions in concurrent applications.
This guide announces the release of mica-mqtt 2.4.x, details the Maven groupId and package name changes, provides a full changelog, migration steps with code examples, and links to documentation and open‑source repositories, helping developers upgrade their MQTT solutions efficiently.
ThreadLocal provides a simple yet powerful way to give each thread its own independent variable, eliminating shared-state conflicts; this guide explains its underlying mechanism, creation methods, basic get/set operations, a complete example with console output, and important usage considerations such as potential memory leaks.
This article explains how to correctly declare Java thread pools using ThreadPoolExecutor, monitor their runtime status, configure parameters for CPU‑bound and I/O‑bound workloads, assign meaningful names, avoid common pitfalls such as unbounded queues and thread‑local leakage, and leverage dynamic pool frameworks.
This guide explains how to implement location‑based job search in a WeChat mini‑program using Solr’s spatial capabilities, covering schema setup, index building, query syntax, performance considerations, and practical code examples, while also comparing Solr with Elasticsearch for similar use cases.
FastExcel is a Java library that builds on EasyExcel to provide high‑performance, low‑memory Excel read/write, stream processing, PDF conversion and a simple API, with detailed usage examples, code snippets, and a comparison of its advantages over EasyExcel.
The author recounts a late‑night incident where a newly launched marketing tool malfunctioned due to a boolean logic error in Java code, describes the chaotic debugging process, presents the faulty and corrected implementations, and confirms the logical equivalence of the final solution.
This article examines Java reflection's advantages and drawbacks, analyzes its core API methods, benchmarks its performance against regular calls, explains why it is slower, and demonstrates how using Hutool's ReflectUtil can dramatically improve execution speed.
This article explains how to replace Spring Boot's default embedded Tomcat container with Undertow, detailing Undertow's features, providing Maven dependency changes, and comparing performance and memory usage through test results, concluding that Undertow offers superior efficiency for high‑concurrency Java web applications.
Java’s String.intern() method adds a string to the constant pool, enabling memory sharing and faster reference comparisons; this article explains its behavior, demonstrates usage with code examples, and discusses performance benefits and cautions for optimal use in real‑world applications.
This article explains how to prepare the environment, configure GraalVM, use Maven plugins, and apply Spring Boot 3.0 AOT and RuntimeHints to compile a Spring Boot application into a fast‑starting native executable, including Docker packaging and underlying AOT principles.
This article shares hard‑won lessons from production incidents and provides practical guidelines—graceful shutdown, proper startup timing, suitable business scenarios, reliability patterns, and idempotent handling—to use Spring Event safely and effectively in Java backend systems.
During a Redis version upgrade of the internal R2M cache service, a Biz thread‑pool exhaustion error was traced to JSF threads blocked on a read lock held by a topology‑updater task, revealing a deadlock caused by shared ForkJoinPool usage and missing lock timeouts.
This article analyzes a thread‑pool exhaustion issue in JD's JSF framework during a Redis cache upgrade, detailing log evidence, stack‑trace analysis, lock contention caused by read/write locks and ForkJoinPool usage, and the steps taken to diagnose and resolve the problem.
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 in Java using Spring, complete with detailed code examples and execution flow.
Reentrant locks are thread‑safe synchronization tools that let the same thread acquire the same lock multiple times without deadlocking, tracking acquisition counts, and offering advantages over traditional synchronized blocks, with Java’s ReentrantLock providing flexible features such as interruptible and timed locking, illustrated by a complete code example.
This guide explains why standard Java collections are not thread‑safe, introduces their concurrent counterparts such as Vector, ConcurrentHashMap, and various BlockingQueue implementations, and provides concrete code examples and usage patterns for safe multi‑threaded programming.
This guide tackles the problem of oversized Spring Boot JARs by showing how to separate library JARs and configuration files from the main artifact, presenting three Maven‑based solutions—spring‑boot‑maven‑plugin, maven‑jar‑plugin, and maven‑assembly‑plugin—complete with configuration snippets, build commands, and deployment tips.
This article introduces the XXL‑JOB open‑source distributed scheduler, compares it with Quartz and other solutions, and provides a step‑by‑step tutorial for server deployment, executor configuration, task development, execution, logging, and the underlying Netty‑based communication design, complete with code examples.
This article describes how to dramatically speed up the import of 60,000+ XML records into MySQL by analyzing the original environment, measuring baseline performance, and applying a series of backend optimizations—including MySQL batch mode, rewriteBatchedStatements, multithreaded asynchronous writes with Disruptor, and XML parsing improvements—ultimately cutting the total runtime from five minutes to just a few seconds.
Through benchmark tests, memory analysis, and code examples, this article presents ten compelling reasons why using a traditional for loop to traverse Java Lists often outperforms Stream.forEach in terms of performance, memory usage, control flow, exception handling, mutability, debugging, readability, and state management.
This article explains why Maven dependency analysis is essential for Java backend projects, demonstrates how to run the analysis with Maven and IntelliJ IDEA, interprets the warnings about used undeclared and unused declared dependencies, and provides best‑practice timing, risks, and shortcuts for maintaining clean dependency trees.
This article explains how Java's ThreadLocal provides thread‑specific storage, enabling safe context management across thread pools, web request handling, database connections, logging, and global data propagation, thereby preventing interference and improving concurrency performance.
This article explains Java 21's virtual threads, their lightweight and auto‑managed nature, demonstrates basic usage and Spring Boot integration, compares performance against traditional threads, and offers additional Java performance tips for high‑concurrency applications.
Byteman is a powerful Java bytecode manipulation tool that lets developers inject custom code at runtime without recompiling, using an event‑condition‑action rule language to trace, modify execution flow, coordinate threads, and collect statistics, with detailed examples of rule syntax, binding, and built‑in actions.
This article explains how to build a multi‑level office approval workflow using the Activiti engine, covering BPMN diagram design, deployment, Java code for process creation, task handling, gateway logic, database schema, API overview, framework comparisons, and further learning directions.
This technical guide breaks down Alibaba's Druid JDBC connection pool, detailing its initialization process, how connections are fetched and returned, the internal threads and condition‑signal coordination, execution handling, recommended configurations, and monitoring integration, all illustrated with code snippets and diagrams.
This article demonstrates how Java 8’s functional interfaces, especially Function and SFunction, can refactor repetitive data‑validation logic into a generic, reusable method, reducing boilerplate, improving readability, and enabling flexible validation scenarios such as checking column values, matching expected values, and verifying values against allowed lists.
The article investigates a MyBatis batch‑insert job that consumes excessive CPU and takes 14 minutes, explains why the foreach‑generated giant INSERT statement is inefficient, and demonstrates how switching to ExecutorType.BATCH or MyBatis dynamic‑SQL batch support reduces the runtime to under two seconds.
This article demonstrates how Lombok’s advanced annotations such as @RequiredArgsConstructor(onConstructor=@__(@Autowired)), @Delegate, @Cleanup, and the combination of @Builder with @Singular can automatically generate Spring‑compatible constructors, delegate methods, manage resources, and build immutable objects, thereby reducing boilerplate and improving code readability in Java backend development.
