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.
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 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.
This article compiles essential Spring and Java utility methods—including assertion checks, object and collection handling, file I/O, resource management, and reflection/AOP tools—providing concise code examples and usage guidelines to help developers avoid redundant code and write cleaner, more reliable applications.
Explore eight practical techniques for achieving asynchronous execution in Java—from low‑level threads and Futures to Spring’s @Async, ApplicationEvent, message queues, and Guava ListenableFuture—complete with code samples, performance insights, and best‑practice recommendations for building responsive backend services.
This article provides a comprehensive guide to Spring transaction management, covering both programmatic (TransactionTemplate) and declarative (@Transactional) methods, explaining their principles, code examples, and how Spring abstracts underlying JDBC steps to simplify database transaction handling for backend developers.
This article explains how to use Spring's BeanRegistrar to programmatically register beans with precise scope, lazy initialization, and custom providers, offering advantages over traditional annotation‑based configuration and demonstrating the approach with a complete GreetingService example.
This guide explains how to implement high‑performance asynchronous APIs in Spring Web using CompletableFuture and ResponseBodyEmitter, covering controller and service code, configuration, request lifecycle, client handling, Nginx settings, and practical recommendations for choosing the right approach.
This article provides a comprehensive guide to Spring XML configuration, covering namespace declaration, bean definition, property injection, scope settings, dependency wiring, AOP setup, transaction management, file imports, and component scanning with clear code examples and explanations.
This article provides a comprehensive overview of the Spring framework, covering its core principles such as Inversion of Control, Dependency Injection, Aspect‑Oriented Programming, and transaction management, while illustrating each concept with diagrams and practical code examples for Java developers.
This article explains the complete Spring Bean lifecycle, breaks it down into six major phases and eleven detailed steps, describes how BeanFactory creates beans in four stages, and clearly distinguishes BeanFactoryPostProcessor from BeanPostProcessor with concrete examples and code snippets.
This article explains how to use Spring's BeanRegistrar interface to programmatically register beans with precise scope, lazy initialization, and custom providers, providing code examples that demonstrate registering default and prototype beans and accessing them via a CommandLineRunner.
This article explains MyBatis streaming queries, introduces the Cursor interface and its methods, demonstrates common pitfalls, and provides three practical solutions—using SqlSessionFactory, TransactionTemplate, or @Transactional—to keep database connections open while processing large result sets efficiently.
This article explains MyBatis streaming queries using the Cursor interface, demonstrates common pitfalls such as closed connections, and provides three practical solutions—including SqlSessionFactory, TransactionTemplate, and @Transactional—to reliably process large result sets with minimal memory usage.
Spring’s @Transactional annotation often appears simple, yet it can silently fail due to unnecessary usage, scope issues, proxy limitations, propagation settings, exception handling, and bean management, leading to unexpected non‑rollback behavior; this article categorizes thirteen common pitfalls and demonstrates each with concrete code examples.
This article explains how to implement an online‑user counting feature using Redis sorted sets (zset) by leveraging the four core commands zadd, zrangeByScore, zremrangeByScore, and zrem, with Java/Spring code examples and optional browser‑fingerprinting for unauthenticated visitors.
Spring’s open‑source nohttp project scans, replaces, and blocks insecure http:// URLs across codebases, ensuring HTTPS usage to prevent man‑in‑the‑middle attacks, and includes modules like nohttp‑cli, nohttp‑checkstyle, and Gradle integration, while addressing cases where HTTPS isn’t feasible.
Learn how to efficiently package local and remote files into a Zip archive while preserving directory structure, using streaming I/O in Java Spring, with safe filename handling, empty directory markers, error handling, and best practices for large or batch downloads.
Learn the fundamentals of finite state machines, explore their core concepts and four key elements, and see how to implement and persist a Spring Statemachine for order processing with detailed code examples, diagrams, and troubleshooting tips, while also understanding common pitfalls and best practices.
This article explains why systems suddenly become unresponsive, outlines nine typical root causes ranging from frontend request spikes to backend thread‑pool exhaustion and missing timeout settings, and walks through a real‑world investigation that reveals how to pinpoint and resolve such blockages.
This article explains how to replace repetitive try‑catch blocks in Java backend development by using Spring's @ControllerAdvice for centralized exception handling, leveraging Assert assertions and custom enum‑based error codes to create clean, maintainable code and consistent API responses.
This article introduces UniHttp, a declarative HTTP‑client framework for Java that replaces traditional HttpClient/OkHttp code with annotation‑driven interfaces, shows quick‑start setup, explains all supported annotations, lifecycle hooks, custom client configuration, and a real‑world enterprise integration example.
This article walks through building a simple Calculator interface, creating a dual‑mode implementation, and then dynamically loading, registering, and unloading user‑supplied JAR files at runtime using reflection or Spring annotation processing, complete with utility methods and a test harness.
This article explains why the Controller layer remains essential in modern Spring applications, identifies common problems such as tangled validation and inconsistent responses, and demonstrates how to introduce a unified result structure, use ResponseBodyAdvice for automatic wrapping, fix String conversion issues, apply JSR‑303 validation, create custom validators, and handle exceptions uniformly.
This article compiles a comprehensive Java interview guide covering object‑oriented fundamentals, method overloading vs overriding, core collection implementations, Spring bean lifecycle, composite index usage, process/thread/coroutine distinctions, Linux IPC methods, design‑pattern principles, Redis roles and data types, relational vs NoSQL trade‑offs, QR‑code login design, and a classic 15‑minute brain teaser.
This article explains how to design and implement a generic asynchronous processing SDK for Java backend services, covering its purpose, advantages, underlying principles, component choices, database schema, configuration, usage patterns, and best‑practice notes, with code examples and diagrams.
This article walks through the ten most useful Spring extension points—including global exception handling, custom interceptors, bean access, @Import usage, startup runners, BeanDefinition modification, initialization callbacks, BeanPostProcessor hooks, destroy callbacks, and custom scopes—providing clear explanations and ready‑to‑use code examples for each.
This article walks through the evolution of a payment API’s idempotency design—from an initially flawed implementation, through naive Redis deduplication and token‑based approaches, to a robust solution that combines distributed locks, double‑checked caching, and state management for reliable, concurrent processing.
This article introduces a Spring‑based library that reduces multi‑step download, compression, and response handling to a single annotation, supporting files, HTTP URLs, strings, collections and custom objects across WebMvc and WebFlux with reactive programming.
The article explains how inconsistent API return types, missing error handling, irrelevant or complex parameters, and lack of proper result objects lead to maintenance headaches, and demonstrates a disciplined approach using a generic ResultBean, standardized controller conventions, and Spring AOP for logging and exception handling.
This article demonstrates how to apply the Chain of Responsibility design pattern together with SOLID principles to refactor a video upload, transcoding, review and publishing workflow, providing clear Java examples, UML diagrams, and Spring integration for a maintainable, extensible solution.
This article explains why asynchronous execution shortens request latency and presents eight practical Java techniques—including raw threads, Future, CompletableFuture, Spring @Async, ApplicationEvent, message queues, ThreadUtil, and Guava ListenableFuture—complete with code examples and usage tips.
This article explains how Spring 3.0's pure annotation mode simplifies bean configuration, demonstrates replacing XML with @Component and @Configuration, covers bean scopes, dependency injection techniques like @Autowired, @Qualifier, @Value, and shows seamless integration of Spring with MyBatis for data access.
This article explains the challenges of distributed consistency when a business operation writes to both MySQL and third‑party systems, presents a financial reimbursement case study, analyzes failure risks, and offers a practical solution that splits large transactions into small, retryable units using Spring and a task table.
While many developers add interfaces to every Service and DAO class, this article argues that with Spring’s dependency injection you can often omit them, examines common reasons for using interfaces, and proposes practical project structures and workflows for both single and multiple implementation scenarios.
This article explains Spring's circular dependency problem, distinguishes when such dependencies are harmless, shows why constructor injection can still fail, and details how Spring's three‑level cache with singleton, early‑singleton, and factory caches resolves setter‑based circular dependencies, including code examples and key source snippets.
This guide explains 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 bean registration or pure Java reflection, complete with utility methods for loading, registering, and cleaning up beans.
Learn how Spring interceptors work, their relationship with WebApplicationContext, various types, configuration methods, execution flow, advanced features, and practical examples such as logging and authentication, plus a comparison with servlet filters and demo results.
This article explains Spring Interceptors, their relationship with WebApplicationContext, various types, configuration methods, execution flow, advanced features, differences from filters, and provides practical logging and authentication examples with code snippets.
Spring 7.0 introduces JmsClient, a modern, stream‑oriented API for JMS messaging that mirrors the design of JdbcClient and RestClient, offering fluent creation, flexible destination configuration, rich QoS options, and simplified send/receive operations compared to the traditional JmsTemplate.
This article presents nine practical methods for loading files from the resources directory in a Spring Boot project, covering ClassLoader, Class, Spring ResourceLoader, ResourceUtils, ApplicationContext, ServletContext, Java IO, NIO, and ClassPathResource approaches.
This article explains how to let users upload a JAR containing a custom implementation of a predefined Java interface, then hot‑deploy the new implementation using either Spring annotation‑based injection or pure reflection, covering interface definition, bean registration, and cleanup.
This article walks through Spring Bean Validation fundamentals, demonstrating how to apply built‑in constraints, create custom validators, use group validation, perform cascading request validation, and enable method‑level checks, all with clear code examples and best‑practice recommendations.
This guide explains what Spring Task is, shows how to add the dependency, enable scheduling annotations, write cron‑based methods, and covers common use cases, pitfalls, and performance tricks for building reliable backend scheduled jobs in Java.
This article explains why static fields injected with @Autowired in Spring can become null, causing NPEs in production, and presents six practical solutions—including removing static fields, using @PostConstruct, static setters, ApplicationContext, singleton patterns, and @Lazy loading—to ensure reliable static dependency injection.
This article explains how to use Spring's TransactionSynchronizationManager to detect active transactions and reliably send Kafka messages either immediately or after transaction commit, illustrated with a payment‑system use case and complete code examples.
