This article introduces a generic asynchronous processing SDK for Java back‑ends, explaining its design principles, advantages, component architecture, database schema, configuration via Apollo, usage steps, and practical demonstrations, while providing complete code snippets and a GitHub repository for reference.
This article introduces a powerful, extensible Spring validation component built on SpEL that handles simple annotations, enum checks, multi‑field logic, and Spring Bean integration, providing step‑by‑step setup, usage examples, custom constraints, and performance considerations for Java backend developers.
This article examines Spring's three transaction management options—@Transactional, TransactionTemplate, and TransactionManager—explaining their mechanisms, common pitfalls such as internal method calls and timeout settings, and provides guidance on when to use each approach with concrete code examples.
When a Spring @Transactional method with REQUIRES_NEW fails to persist audit logs after a rollback, the issue often stems from misconfigured rollback rules, caught exceptions, self‑invocation, non‑public or final methods, or incorrect propagation settings, all of which prevent the new transaction from committing.
The article examines five scenarios where Spring's @Transactional annotation falls short—stock shortage, MQ messaging, batch processing, logging, and isolation/timeout settings—and demonstrates six practical techniques, including programmatic transactions, parameter tuning, transaction synchronizers, event listeners, manual transaction control, and propagation strategies, all backed by runnable demo code.
This article shows how to eliminate most try‑catch blocks in Java Spring applications by using @ControllerAdvice, custom assertion utilities, and enum‑driven error codes, providing a clean, internationalized error‑response format and even turning 404s into catchable exceptions.
IntelliJ IDEA 2025.3.1 rolls back a controversial Query Console change, fixes over 200 bugs—including SQL workflow, WSL‑Gradle issues, Spring stack problems, and terminal glitches—making it a critical update for Java, Spring, and full‑stack developers seeking a more stable IDE experience.
After interviewing 150 candidates in two months, I finally met a developer whose resume perfectly matched our stack, demonstrated deep Java, SpringAI, and AI‑coding tool expertise, answered extensive technical questions ranging from SQL optimization to micro‑services, and received an immediate offer with a competitive salary package.
During a Spring‑based interview platform project, the author discovered four typical bugs introduced by Claude Code—transactional self‑invocation loss, AI‑generated NullPointerExceptions, async task failures after entity deletion, and Redis Stream message buildup—and explains the root causes and concrete remediation steps.
This article walks through Spring 6’s core upgrades—including JDK 17 baseline, Project Loom virtual threads, @HttpExchange declarative clients, RFC 7807 ProblemDetail handling, GraalVM native‑image compilation, and Micrometer‑Prometheus monitoring—showing concrete code, performance numbers, migration steps, and real‑world e‑commerce use cases.
This article presents a comprehensive, end‑to‑end solution for preventing duplicate consumption in RabbitMQ by combining architecture design, routing strategies, idempotent controls, state machines, and ACK mechanisms, and details six concrete implementation options with code examples.
This article explains the design and implementation of a generic asynchronous processing SDK for Java, covering its purpose, advantages, core principles, component choices, design patterns, configuration via Apollo, usage steps, safety considerations, and provides complete SQL and Spring configuration examples along with a GitHub repository link.
This article analyzes seven typical reasons why Spring transactions become ineffective or fail to roll back—such as wrong method visibility, final modifiers, self‑invocation, unmanaged beans, multithreading, non‑transactional tables, mis‑configured propagation or exception handling—and provides concrete code examples and practical solutions.
The article demonstrates how to let a system expose an interface, accept user‑written JARs that implement it, and hot‑replace the implementation at runtime using either Spring‑managed beans or pure reflection, including bean registration and cleanup.
The article explains how @NotNull, @NotBlank, and @NotEmpty annotations from javax.validation differ in their constraints on primitive types, strings, collections, and maps, and shows why adding @Validated to method parameters is required for the validations to take effect.
This article shows how to let users upload a JAR that implements a predefined interface, then hot‑deploy the new implementation at runtime using either Spring annotation‑based registration or plain reflection, including bean registration, removal, and a test harness.
The article explains common pitfalls that cause Spring @Transactional to fail or not roll back, such as incorrect method visibility, final or static modifiers, internal method calls, beans not managed by Spring, multithreading, unsupported database engines, misconfigured propagation, swallowed exceptions, and improper rollback settings, and offers practical solutions for each case.
This article explains Spring's @Transactional default rollback behavior, why checked exceptions like IOException don't trigger a rollback, illustrates the resulting data inconsistency with a money‑transfer example, and shows how to fix the issue by explicitly configuring the rollbackFor attribute.
This article walks through a real‑world case where a batch‑score query API that originally took up to 20 seconds was systematically optimized through index tuning, multithreaded execution, and request‑size limiting, ultimately achieving sub‑second response times.
The article explains why using @NotEmpty fails to detect blank strings, demonstrates the issue with a simple demo, shows the correct use of StringUtils.isBlank, and clarifies the differences between @NotNull, @NotEmpty, and @NotBlank annotations in Java validation.
This article walks through the core upgrades in Spring 6 and Spring Boot 3—raising the JDK baseline, adopting Project Loom virtual threads, using the new @HttpExchange declarative client, standardizing error responses with ProblemDetail, compiling to GraalVM native images, and adding Prometheus monitoring—while providing concrete code examples, performance numbers, and a step‑by‑step migration roadmap.
The article explains the concept of parent‑child containers in Spring, outlines three key benefits—modularization, scoped bean visibility, and configuration reuse—provides step‑by‑step XML and Java code examples, and shows how the containers integrate with Spring MVC to create a cleaner, more maintainable application architecture.
This guide explains how to use Spring's built‑in Mapped Diagnostic Context (MDC) to generate a traceId for each request, configure Logback to include it in logs, and propagate the traceId through HTTP filters, RabbitMQ messages, thread‑pool tasks, and XXL‑Job scheduled jobs, complete with code examples and configuration snippets.
The article demonstrates how to replace scattered try‑catch blocks with a clean, unified exception handling strategy in Spring, using @ControllerAdvice, custom BaseException, enum‑driven error codes, and Assert utilities, while also standardizing API responses and handling common MVC errors such as 404.
The article argues that traditional Spring Controllers impose heavy, repetitive scaffolding that outweighs business value, and demonstrates how a functional Java API can replace class‑based controllers with simple handler functions, reducing cognitive load, test complexity, and development overhead.
This tutorial shows how to eliminate repetitive @Autowired injections, logging, and try‑catch blocks in Spring controllers by using a custom ServiceManager component that leverages Java 8 Lambda expressions to locate services, cache metadata, and execute methods with unified response handling.
This article walks through building a Spring MVC interceptor that leverages Redis to enforce per‑IP request limits, explains configurable parameters, shows how to apply protection selectively via mapping rules or custom annotations, and discusses practical pitfalls such as sliding‑window logic, path‑parameter handling, and real‑IP detection.
A reproducible benchmark of 62 languages shows Java running on modern JVMs is only ~17% slower than C, more than 13 times faster than Python, while Spring’s runtime overhead can inflate pure‑Java code by 30×, highlighting common misconceptions about Java performance and how to avoid them.
This guide shows how to eliminate manual logging of user and order identifiers in a Java e‑commerce system by declaring log placeholders, storing values in ThreadLocal, and using a custom @UserLog annotation with Spring AOP to automatically populate MDC variables for Log4j2.
IntelliJ IDEA 2025.3.1 rolls back the controversial Query File feature, fixes over 200 issues, and delivers crucial improvements for Windows + WSL, Spring, Kotlin‑MongoDB, Java debugging, terminal stability, and frontend tooling, making it a must‑upgrade for developers.
This article explains how to handle long‑running Spring endpoints by using three asynchronous streaming tools—ResponseBodyEmitter, SseEmitter, and StreamingResponseBody—showing their appropriate scenarios, configuration details, and complete code examples that keep the servlet thread free and avoid timeout problems.
This tutorial explains how to register and inject a third‑party implementation like SwimCoach into a Spring Boot application using a @Configuration class and @Bean methods, covering bean creation, custom IDs, qualifier usage, and practical scenarios such as integrating AWS S3 clients.
This article uses a coffee‑shop analogy to explain Spring event listeners, demonstrates how to define, publish, and handle events, presents three techniques for handling massive traffic, shares real‑world incidents and lessons, compares listeners with MQ, and offers performance‑tuning tips and best‑practice rules.
This article provides a detailed walkthrough of Spring's circular‑dependency resolution, explaining the three‑level cache mechanism, step‑by‑step bean creation flow, and the underlying source‑code logic, complete with diagrams and code examples for deep understanding.
This article dissects the SpringBoot class‑loading mechanism, explaining how the JVM parent‑delegation model is selectively overridden with custom class loaders like LaunchedURLClassLoader and RestartClassLoader, and how these changes integrate with Spring's bean lifecycle, auto‑configuration, and practical troubleshooting techniques.
IntelliJ IDEA 2025.3.1 quickly follows the 2025.3 major release, fixing over 200 issues, reinstating the classic Query Console, addressing WSL‑related Java debugging problems, stabilizing Gradle/Maven sync for large multi‑module projects, improving Spring tooling, Java debugging, Kotlin‑MongoDB support, and correcting terminal and TypeScript bugs.
Most Java developers mistakenly equate writing try‑catch blocks with proper exception handling, leading to lost context, noisy logs, and fragile code, while senior engineers employ custom unchecked exceptions, a layered hierarchy, global handlers, RFC‑7807 responses, and observability tools to build predictable, traceable, and recoverable systems.
This article shares hard‑learned production experience on using Spring Event, explaining why services must shut down gracefully before publishing events, how startup timing can cause event loss, which business scenarios fit the publish‑subscribe model, and practical reliability techniques such as retries and idempotency.
This guide explains the concept of multi‑DataSource coexistence, when it is appropriate, step‑by‑step configuration for MySQL and TDengine, transaction manager handling, custom annotations, mapper scanning, differences from dynamic routing, common pitfalls, and best‑practice usage in a Spring‑MyBatis backend.
This guide explains how to use Spring Retry's declarative @Retryable annotation together with @Transactional, as well as the programmatic RetryTemplate and TransactionTemplate, to ensure each retry runs in its own transaction and handles transient database failures reliably.
IntelliJ IDEA 2025.3 merges Ultimate and Community editions into a single installer, unlocks many formerly premium features for free users, adds command completion, full Java 25 support, a new Islands theme, AI enhancements, expanded framework integrations, and a suite of productivity plugins for modern development workflows.
IntelliJ IDEA 2025.3 introduces a unified distribution, extensive Spring and language support, improved Git integration, terminal and build tool enhancements, better web development handling for large monorepos, and numerous performance optimizations, all while fixing over 800 issues across the IDE.
This guide compares major Java MQTT development options—including native Paho client, Spring Integration, Spring Boot starters, and cloud provider SDKs—detailing their features, pros and cons, sample code, and ideal use cases, and offers a decision‑making flow to help you select the best fit for your project.
The latest Spring AI 2.0 and Spring Cloud 2025.1 releases make virtual threads the default concurrency model, showing why Java 21 is essential for AI workloads, how Spring Cloud drops Reactive Kafka, adds MVC‑plus‑virtual‑thread support, and what pitfalls developers must avoid.
The article dissects Spring 6 and Boot 3's core capabilities—JDK 17 baseline, Project Loom virtual threads, declarative @HttpExchange client, RFC 7807 error standardization, GraalVM native images, Jakarta EE 9 migration, and Prometheus monitoring—showing benchmark gains and a migration roadmap for high‑concurrency e‑commerce services.
This article examines the need for comprehensive business operation logging in a central system, outlines the benefits of audit, security, monitoring, and analysis, and walks through three progressive solutions—AOP with annotations, AOP with SpEL, and a Binlog‑based time‑window approach—detailing their implementations, trade‑offs, and architectural considerations.
This guide walks you through what Spring Task is, how to enable it in three simple steps, decode cron expressions, explore six real‑world use cases, unlock four advanced features, avoid common pitfalls, and apply performance‑tuning and future‑proofing techniques for robust Java scheduling.
This article explains Spring's default eager bean creation, demonstrates how to add @Lazy annotations or a global property to defer bean instantiation until needed, and discusses the benefits and drawbacks of lazy loading with code examples and runtime observations.
This article explains Netflix's open‑source Ribbon client‑side load balancer, detailing how it intercepts @LoadBalanced RestTemplate calls, resolves service names to IPs using various algorithms, and forwards requests via HttpClient, while highlighting its key features such as in‑process balancing, multiple strategies, fault‑tolerance, and protocol support.
This article explains Spring's circular‑dependency problem, introduces the three‑level cache (singletonObjects, earlySingletonObjects, singletonFactories), walks through the full execution flow with code examples, and clarifies why each cache level and AOP proxy factories are essential for correct bean initialization.
This article introduces Spring Boot 3's TransactionExecutionListener, explains its purpose compared to traditional transaction hooks, provides a complete code example—including entity, service, custom listener, and test cases—and demonstrates how to observe transaction phases and handle both successful commits and rollbacks.
The article details Tuhu Auto’s Shanghai Java backend compensation (30k‑33k monthly with 14.4‑month salary and 2‑3w signing bonus), outlines the company’s market position, and provides a comprehensive list of technical and HR interview questions covering JVM, concurrency, MySQL, Spring, DDD, distributed locking, rate limiting, and more.
This article explains why the @Autowired field injection in Spring is often discouraged, compares it with @Resource and constructor injection, shows practical code examples and error scenarios, and provides guidance on choosing the most appropriate dependency‑injection method for robust backend development.
This article breaks down Spring’s layered architecture and walks through ten core design patterns—factory, singleton, proxy, template method, observer, adapter, decorator, strategy, chain of responsibility, facade, and delegate—showing how they appear in real interview scenarios and how mastering them can turn a tough interview question into a winning advantage.
This article explains how Spring Framework 7 introduces the BeanRegistrar interface to replace the cumbersome ImportBeanDefinitionRegistrar, demonstrating the new API with concise code examples, comparing old and new approaches, and providing a complete practical example for dynamically registering beans based on runtime configuration.
Fast‑Retry is a high‑performance asynchronous retry framework that can handle millions of tasks with far lower latency than traditional synchronous retry libraries like Spring‑Retry or Guava‑Retry, thanks to its non‑blocking design, customizable retry logic, and support for both programmatic and annotation‑based usage.
This guide shows how to let users upload a JAR that contains a custom implementation of a predefined Java interface, then hot‑replace the implementation at runtime using either Spring‑managed bean injection or pure reflection, with full code examples and a test harness.
This article combines salary insights for ZTE offers, practical internship interview tips, a deep dive into Spring bean‑injection annotations, a side‑by‑side comparison of MySQL InnoDB and MyISAM, Redis usage patterns, and JVM OutOfMemoryError diagnostics to help you excel in Java backend interviews.
This article compares @Resource and @Autowired in the Spring framework, covering their origins, injection order, supported injection styles, and ideal usage scenarios to help developers choose the right annotation for loosely coupled, maintainable applications.
This article explains four common idempotency strategies—token, database unique index, distributed lock, and request‑body digest—detailing their core ideas, key concepts, and providing ready‑to‑copy Spring/Redis code examples to prevent duplicate requests in high‑traffic backend systems.
The article explains how Jackson Views can consolidate multiple DTO classes into a single DTO by using view interfaces and @JsonView annotations, dramatically reducing code duplication, simplifying maintenance, and providing flexible field selection for different API scenarios.
This article introduces a Spring‑based download library that lets developers add a single @Download annotation to any controller method to automatically handle file, HTTP resource, or text downloads, supporting concurrent loading, compression, and both WebMVC and WebFlux response models.
This article explains how a large e‑commerce platform implements a high‑performance, asynchronous Excel export mechanism using annotation‑driven declarative programming, AOP interception, Quartz scheduling, RocketMQ messaging, and OSS storage to handle massive data sets without blocking user requests.
This article explores why precise per‑minute API call statistics are essential for performance bottleneck detection, capacity planning, security alerts, billing, and troubleshooting, and presents five practical implementations—including fixed‑window counters, sliding windows, AOP‑based interception, Redis time‑series storage, and Micrometer‑Prometheus integration—along with their trade‑offs and capacity‑planning guidelines.
In this detailed case study, the author walks through diagnosing and fixing severe throughput bottlenecks in a Java Spring‑based B2B service, covering lock contention, slow SQL, excessive logging, thread‑pool tuning, JVM memory adjustments, and the impact of bean creation on performance, ultimately achieving nearly a ten‑fold increase in requests per second.
This article explains why @Transactional fails in multithreaded MySQL insert scenarios, demonstrates how to split large data sets, configure a thread pool, and use SqlSession with manual commit to guarantee atomicity across parallel threads, complete with runnable code examples and test results.
This article explains how to handle large‑scale data insertion with multithreading in Spring, why @Transactional fails in child threads, and demonstrates two approaches—manual SqlSession control and thread‑pool execution—to guarantee atomic rollback across all threads.
Using a coffee‑shop metaphor, this article explains how Spring’s event‑driven model—event definitions, publishing, and listeners—enables scalable, decoupled backend systems, compares listeners with MQ, shares performance benchmarks, and provides best‑practice guidelines for reliable, high‑throughput applications.
This article explains the concepts of Single Sign‑On (SSO) and the Central Authentication Service (CAS), then provides a detailed, code‑rich tutorial for setting up a CAS server, configuring clients, disabling HTTPS for development, and testing the end‑to‑end SSO workflow using Java and Spring.
This article explains why traditional if‑else payment routing is hard to maintain, demonstrates how Java enums combined with functional interfaces and the strategy pattern can centralize behavior, improve extensibility, and integrate cleanly with Spring, providing a robust, testable solution for payment channel selection.
This article examines six practical techniques for measuring the latency of online interfaces in Java, from simple System.currentTimeMillis() calls to advanced AOP, interceptors, filters, and production‑grade monitoring tools like Micrometer and APM, comparing their precision, intrusiveness, and suitable scenarios.
This article explains how to automatically include userId and orderId in log messages by defining log placeholders, storing these values in a thread‑local MDC map, and using a custom @UserLog annotation together with Spring AOP to inject the data at runtime, simplifying debugging and improving productivity.
Spring’s team announced that RestTemplate will be deprecated in Spring Framework 7.0 and removed later, outlining its limitations and presenting the new RestClient as a modern, fluent alternative, while also recommending WebClient for reactive scenarios and offering migration strategies for existing projects.
A backend admin service failed to start due to a Spring circular‑dependency error where a bean was injected in its raw form before AOP proxy creation, exposing the limits of Spring’s three‑level cache and prompting a detailed analysis of the root cause and practical solutions.
This article explains how to improve the performance of large PostgreSQL IN queries by splitting them into smaller batches, executing them concurrently with Spring AOP and custom annotations, and then merging the results, providing a reusable solution for high‑volume database operations.
This article introduces Fast‑Retry, a high‑performance asynchronous multi‑task retry framework for Java, compares its speed against Spring‑Retry and Guava‑Retry, and provides step‑by‑step code examples for dependency setup, task creation, annotation usage, and custom retry annotations.
A Java Spring application repeatedly stalled due to Redis connection pool deadlocks, and the investigation walks through using system tools, JVM thread dumps, and Arthas to pinpoint the issue, then shows how proper pool configuration and safe Redis access prevent the API from freezing.
This comprehensive guide explains why design patterns matter, links them to SOLID principles, enumerates the 23 classic GoF patterns with Java examples, compares commonly confused patterns, introduces modern architectural patterns, shows how they integrate with Spring, and offers a practical learning roadmap for developers.
The article shares ZTE salary offers and interview tips, then dives into technical deep‑dives on Spring bean injection annotations, compares MySQL InnoDB and MyISAM, explains Redis usage patterns, and walks through JVM OutOfMemoryError diagnosis with concrete code and tooling examples.
This concise guide explains Spring’s core concepts—including the Inversion of Control container, how beans are created and managed, the different bean scopes, and the full bean lifecycle with key extension points—providing clear analogies and practical configuration examples.
This article explains how to replace repetitive try‑catch blocks in Spring applications by using @ControllerAdvice, custom Assert utilities, and enum‑based exception definitions, providing a clean, unified error‑handling mechanism with consistent response structures and environment‑aware messaging.
This article explains six common and dangerous pitfalls when using Spring's @Transactional annotation, illustrates each with problematic code examples, and provides concrete best‑practice solutions to ensure correct transaction propagation, self‑invocation handling, exception rollback, data source consistency, transaction scope, and method visibility.
This article walks through various Java retry mechanisms—including manual loops, static and dynamic proxies, AOP, Spring Retry annotations, and Guava‑retry—explaining their implementations, advantages, drawbacks, and when to choose each approach for robust remote service calls.
This article explains how to solve interleaved log lines in multi‑threaded pods by using a TraceId stored in SLF4J MDC, propagating it via HTTP headers, adapting thread pools and Spring task decorators, and integrating SkyWalking to enrich Logback patterns for end‑to‑end request tracing.
This comprehensive guide explains the fundamentals and practical implementations of task scheduling in Java, covering Linux crontab, JDK Timer, ScheduledExecutorService, Quartz, Spring Schedule, and popular distributed schedulers like SchedulerX, elastic‑job, XXL‑Job and LTS, with code examples and configuration details.
Spring announced that RestTemplate will be deprecated in Spring Framework 7.0 and removed later, outlining a migration path to the newer RestClient for synchronous use and WebClient for reactive scenarios, while providing a timeline and practical guidance for developers.
This article explains how to structure API responses in a microservice environment by using a standard JSON format, custom status code ranges, a Result wrapper class, and Spring annotations with interceptors to automatically package and handle responses and errors in a clean, maintainable way.
This article explains the challenges of manual JDBC transaction handling, introduces Spring's unified transaction API with PlatformTransactionManager, TransactionDefinition, and TransactionStatus, demonstrates code examples for programmatic and declarative transactions, and discusses common pitfalls such as non‑public methods, self‑invocation, and exception handling.
This tutorial explains how to implement sequential streaming for multipart uploads and downloads in Spring MVC and reactive streaming in Spring WebFlux, enabling large files to be processed without excessive memory usage and improving performance for high‑load web applications.
This guide explains Spring and Spring Boot's highly extensible architecture by detailing nine core extension points, their injection timing, practical uses, and best‑practice recommendations, enabling developers to customize the container lifecycle from startup to runtime.
This article explains why @Transactional fails in multi‑threaded Spring services, provides a utility for splitting large data sets, shows thread‑pool configuration, demonstrates a failing transaction scenario, and presents a solution using manual MyBatis sqlSession commit to guarantee atomic rollback across all threads.
An internal sandbox API kept hanging for a week, prompting a deep dive with top, jstack, and Arthas that revealed Redis connection pool threads stuck in wait, leading to configuration tweaks and proper connection release to restore service stability.
This article demonstrates how to replace cumbersome if‑else chains in payment processing with Java enums that encapsulate behavior, leveraging functional interfaces, the strategy pattern, and Spring integration to achieve cleaner, extensible, and testable code while adhering to the Open/Closed principle.
This article explains why asynchronous execution is essential for reducing latency in Java applications and walks through eight practical implementations—including threads, Future, CompletableFuture, Spring @Async, ApplicationEvent, message queues, ThreadUtil, and Guava—complete with code examples and usage tips.
This article explains how to simplify Spring MVC controller code by introducing a unified response format, leveraging ResponseBodyAdvice for automatic wrapping, applying JSR‑303 validation for request parameters, creating custom validators, and handling exceptions globally to keep business logic clean and maintainable.
This guide compiles high‑frequency Java interview questions—from core language concepts and collections to JVM tuning, MySQL indexing, Redis caching, Spring frameworks, micro‑services, and MQ reliability—providing a comprehensive reference for candidates targeting small‑to‑mid‑size companies.
The article explains how Spring Framework 6’s @HttpExchange annotation and the new HTTP service registry introduced in Spring Framework 7 enable developers to declaratively define, configure, and manage AI‑driven HTTP clients as Spring beans, reducing boilerplate, supporting multiple providers, and integrating seamlessly with Spring Boot, Cloud, and Security.
Java 25 introduces major upgrades to virtual threads, offering dramatically lower memory usage, near‑zero creation cost, and efficient I/O handling, and this guide explains their advantages, compares them with traditional thread pools and @Async, provides Spring Boot 3.5 configuration examples, and highlights pitfalls and best‑practice tips.
This article explains the Strategy (Policy) Pattern, illustrates its structure, and demonstrates a practical Spring-based implementation where different message types are processed by distinct strategy services, using an enum to map types to beans for flexible, interchangeable algorithms.
This article introduces the Strategy design pattern, explains its core concept of interchangeable algorithms, and demonstrates a practical Spring-based implementation that routes various message types to specific services using an enum‑driven bean lookup, enabling flexible updates to Elasticsearch for merchant search and analytics.
