This article demonstrates how to accelerate a one‑million‑row database query by adding indexes and using a multithreaded Java Spring controller with MyBatis, showing code examples, performance tests, and suggestions for further optimization.
This article explains the concept of idempotency, identifies which HTTP methods are naturally idempotent, and demonstrates a complete Java Spring solution—including custom annotations, AOP handling, token generation, and Redis storage—to guarantee safe retry and duplicate‑request protection.
This article explains why retry mechanisms are essential for remote service calls, compares several implementation approaches—including manual loops, static and dynamic proxies, AOP, Spring Retry annotations, and Guava‑Retry—provides complete Java code examples, and discusses the advantages and drawbacks of each method.
This article walks through seven retry implementations for Java services—manual loops, static proxy, JDK dynamic proxy, CGLib proxy, custom AOP, Spring Retry annotations, and Guava‑retry—showing code examples, analyzing their pros and cons, and recommending the best fit for different project contexts.
This article explains Spring's conditional configuration features—including @Profile, @Conditional, and various @ConditionalOn* annotations—showing how to dynamically register beans based on environment, classpath, properties, or other bean presence, with detailed code examples and usage guidelines.
This article presents a detailed collection of 31 Java‑related architecture diagrams—including class loader, JVM, Spring, Hibernate, Struts, Android, cloud computing, Linux kernel, and various enterprise frameworks—providing a visual guide for backend developers seeking a broad understanding of Java ecosystem structures.
This article explains how to enhance SpringBoot's native @Scheduled tasks with the spring-boot-starter-super-scheduled library, allowing dynamic creation, modification, and cancellation of scheduled jobs at runtime without altering existing annotations, and details the underlying implementation using BeanPostProcessor, CGLIB proxies, and a custom task manager.
This article explains three ways to inject a specific service implementation in Spring—using @Qualifier with @Autowired, using @Resource with type or name attributes, and naming @Service beans—detailing their semantics, bean‑matching rules, and providing complete code examples for each approach.
This article walks through the problem of scattered try‑catch blocks in Java back‑ends, explains the use of Spring's @ControllerAdvice together with a custom Assert‑based validation and error‑code enum, and demonstrates a complete unified exception handling solution with production‑ready response formatting and extensive code examples.
The article explains how to replace repetitive try‑catch blocks in Java Spring applications with a unified exception handling mechanism that leverages @ControllerAdvice, custom BaseException, Assert utilities, and enum‑based error codes to produce consistent, environment‑aware error responses.
This article introduces the fundamentals of state machines, explains the four core concepts, explores domain‑specific languages (DSL) and their classifications, and provides practical Java examples using Spring Statemachine and the COLA framework, ending with a comparison and adoption guidance.
This article demonstrates how to reduce repetitive Java code in business applications by applying the Template Method and Factory design patterns, leveraging Spring’s IoC for dynamic cart selection, using custom annotations with reflection to serialize API parameters, and employing bean‑mapping utilities to automate DTO‑DO conversions, thereby improving maintainability and scalability.
This article introduces Robustdb, a compact Java library that implements client‑side read‑write splitting and method‑level routing for MySQL databases, explains its architecture, core code components, dynamic read‑pool allocation strategy, and performance comparison with Atlas, while providing practical implementation details and configuration guidance.
This article reviews six theoretical approaches for maintaining MySQL‑Redis data consistency, evaluates their pros and cons, and presents a practical implementation using Java Spring, transactional updates, cache deletion, and asynchronous queue handling to achieve both real‑time and eventual consistency in high‑concurrency systems.
IntelliJ IDEA 2023.2 introduces a suite of enhancements—including a Run‑window profiler, inline return breakpoints, automatic test reruns for Gradle/Maven/JPS, WSL‑based Tomcat debugging, TLS‑enabled gRPC requests, Swagger and OpenAPI support, shared index generation, and numerous UI and code‑completion upgrades—streamlining Java development workflows.
This article explains how to achieve API idempotency in high‑concurrency scenarios by creating a custom @RepeatSubmit annotation, using AOP interception, Redis setNx for locking, and a request‑wrapper to allow repeated reading of request parameters in Spring applications.
This article explains why transaction control is essential for database‑backed applications, compares native JDBC/MyBatis handling with Spring's unified approach, details the core transaction APIs, and walks through the AOP‑based mechanism—including @EnableTransactionManagement, proxy generation, and CGLIB interception—that automatically opens, commits, and rolls back transactions at runtime.
This article explains how Spring 5.3’s @Scheduled and @Async annotations are processed, detailing the bean lookup sequence for TaskScheduler and AsyncConfigurer, the default thread pool creation mechanisms, and the configuration of web asynchronous support, with code examples for each step.
This article explains how Spring AOP integrates AspectJ using CGLIB or JDK dynamic proxies, walks through a complete logging aspect example, and details the internal registration, proxy creation, and invocation processes that enable cross‑cutting concerns without modifying business code.
This article explains how Lombok's @RequiredArgsConstructor can replace multiple @Autowired and @Resource annotations by promoting constructor injection, compares field, constructor, and setter injection in Spring, and demonstrates the resulting cleaner code with practical examples.
This article explains how to enable cross‑node WebSocket communication in a distributed Spring application by publishing messages to a Redis or Kafka topic, tracking user connections, and routing messages to the appropriate server instance, complete with full code examples and configuration details.
This article explains the ACID properties of transactions and compares various implementation approaches—including database‑level mechanisms, Spring single‑datasource transactions, and distributed transaction frameworks such as Seata and RocketMQ—while analyzing their advantages, drawbacks, and suitable scenarios.
This article curates the most valuable Spring I/O 2023 video sessions—covering the latest Java version adaptations, Spring Framework and Boot innovations, cloud‑native deployments, security, observability, and architectural best practices—providing concise Chinese summaries so developers can quickly identify which talks merit deeper viewing.
This article summarizes the key pitfalls and recommended practices for creating, configuring, monitoring, and naming Java thread pools, including proper declaration, parameter tuning for CPU‑ and I/O‑bound workloads, avoiding OOM and deadlocks, and leveraging dynamic pool frameworks.
This article introduces Spring 6.1’s new synchronous RestClient, showing how to perform basic GET and POST requests, convert responses to objects, handle errors with onStatus, and use the advanced exchange method for custom request‑response processing, positioning RestClient as a modern replacement for RestTemplate.
This article explains three practical ways to specify which Spring bean to inject in a controller, compares @Autowired and @Resource annotations, clarifies the role of @Service, and provides complete Java code examples for each approach.
The article explains why the error "Transaction rolled back because it has been marked as rollback‑only" occurs in a Java Spring service when using MyBatis‑Plus saveBatch, how hidden @Transactional annotations cause hidden nested transactions, and presents a practical workaround by replacing the batch operation with a custom mapper.
The article explains Java's ThreadLocal mechanism, detailing how each thread maintains its own ThreadLocalMap, provides practical code examples, examines the underlying source implementation—including set and get methods—and discusses potential memory‑leak pitfalls and ways to avoid them.
This article explains how to use @ControllerAdvice and @RestControllerAdvice for both local and global exception handling in Spring, demonstrates limiting handlers by annotation, controller class, or package, and clarifies the precedence rules between local and global handlers.
This article provides a comprehensive overview of Spring’s Assert utilities and a wide range of Spring Framework helper classes—including ObjectUtils, StringUtils, CollectionUtils, FileCopyUtils, ResourceUtils, StreamUtils, ReflectionUtils, and AOP utilities—detailing their purpose and key method signatures for Java backend development.
This article explains the concepts, advantages, disadvantages, and real-world use cases of four essential design patterns—Chain of Responsibility, Template Method, Publish‑Subscribe, and Strategy—providing detailed Java and Spring code examples to help developers apply them effectively.
This article walks you through building a minimal Spring Boot demo, setting breakpoints, analyzing call stacks and logs, and tracing the @Transactional rollback logic in the framework source code to understand why certain methods roll back or commit.
This article explains how to protect high‑concurrency Java applications using rate‑limiting techniques, covering basic algorithms such as counter, leaky‑bucket and token‑bucket, demonstrating a single‑node implementation with Guava’s RateLimiter and custom annotations, and showing a distributed solution based on Redis and Lua scripts.
This article demonstrates how to replace tightly‑coupled if‑else or switch‑case parser selection with the Service Locator Pattern in a Spring Java application, enabling easy addition of new file‑type parsers without modifying client code and adhering to the open‑closed principle.
This article compares Spring's @Autowired and JDK's @Resource annotations, detailing their injection mechanisms, parameter differences, default behaviors, and usage scopes with code examples, while also offering interview advice and promoting a Java interview guide.
This article explains how to execute two dependent tasks in parallel with CompletableFuture, why the usual @Transactional annotation fails in a multi‑threaded environment, and provides a programmatic transaction solution that copies Spring's transaction resources between threads to guarantee atomic commit or rollback across all parallel operations.
The article explains how Spring’s IoC container, dependency injection, singleton beans, and AOP simplify Java backend development by abstracting object creation, configuration, and cross‑cutting concerns, illustrated with code examples and practical scenarios such as conditional bean loading and Redis client selection.
This article investigates how Spring generates bean names from annotated classes, explains the default lower‑casing rule, highlights the special case when the first two characters are uppercase, and shows the underlying JDK decapitalize method through source‑code exploration.
This article introduces the fundamentals of finite state machines, explains their four core concepts, demonstrates how to model order workflows with state diagrams, and provides a comprehensive guide to implementing, configuring, persisting, and testing Spring Statemachine in a Java backend, including solutions for exception handling and AOP enhancements.
This article introduces eight practical approaches for achieving asynchronous execution in Java—including raw threads, Future, CompletableFuture, Spring @Async, ApplicationEvent, message queues, Hutool ThreadUtil, and Guava ListenableFuture—providing code samples, configuration tips, and discussion of each method's advantages and drawbacks.
This article explains the concept of coupling, demonstrates how traditional object creation leads to high coupling, and shows how using interfaces, the factory pattern, and reflection—culminating in Spring IOC—can dramatically lower coupling, improve reuse, and simplify maintenance in Java backend development.
This article provides a comprehensive guide to Spring's property injection techniques, covering setter and constructor injection using both XML and Java annotations, external configuration with @PropertySource, and advanced SpEL expressions, complete with runnable code examples and output screenshots.
This article explores a real‑world scenario where a support manager faces nightly batch job interruptions, analyzes common database and environment failures, and presents a systematic redesign of the batch framework and executor to enable automatic retry, reducing manual intervention and improving operational reliability.
The article explains Spring's three‑level cache mechanism for resolving singleton circular bean dependencies, walks through bean lifecycle stages, compares field, setter and constructor injection, shows configuration to enable circular references, and details the internal code paths that expose early bean references.
This article explains why ThreadLocal can cause information loss, corruption, or OOM in Java applications and presents two practical approaches—Java agent bytecode manipulation and proxy‑based thread‑pool wrappers—along with concrete Spring Sleuth implementations and testing results to ensure safe propagation and cleanup.
This article explains how to implement the Strategy, Factory Method, and Builder design patterns within a Spring application to create a flexible reward‑distribution system, providing detailed code examples, usage guidelines, and best‑practice considerations for each pattern.
This article explains the different Spring dependency injection methods, compares @Autowired and @Resource annotations, outlines the pros and cons of each injection style, and clarifies why IntelliJ IDEA issues a warning for @Autowired but not for @Resource.
The article explains the differences between Spring's @Autowired and @Resource annotations, outlines the pros and cons of various dependency injection methods, and clarifies why IntelliJ IDEA issues a warning for field injection with @Autowired while treating @Resource as acceptable, emphasizing portability and coupling concerns.
This article explains the motivations for moving a Java 8 project to JDK 11, compares JDK 11 and JDK 17, outlines JDK 11’s key features, details Tomcat 8.5 differences, provides step‑by‑step migration instructions, and shares troubleshooting tips for common upgrade issues.
This article explains Spring's common dependency injection methods, compares @Autowired and @Resource, outlines the pros and cons of constructor, setter, and field injection, and reveals why IntelliJ IDEA flags only @Autowired while ignoring @Resource.
PowerJob is a modern distributed job scheduling framework that addresses the limitations of Quartz, XXL‑Job and SchedulerX by offering a web UI, rich scheduling strategies, DAG workflow support, lock‑free high‑performance scheduling, multiple processor types and step‑by‑step quick‑start instructions for developers.
This article provides a detailed overview of Java backend utilities, covering Spring's Assert class for logical checks, common ObjectUtils and StringUtils methods, collection helpers, file and stream utilities, as well as reflection and AOP tools with practical code examples.
This article explains what asynchronous execution is, compares it with synchronous processing, and presents eight practical Java implementations—including raw threads, Future, CompletableFuture, Spring @Async, ApplicationEvent, message queues, Hutool ThreadUtil, and Guava ListenableFuture—complete with code samples and usage tips.
This article explains the fundamentals of finite state machines, introduces the four core concepts of state, event, action, and transition, and demonstrates how to model and persist order workflows using Spring Statemachine with Java code examples, database schema, and AOP-based error handling.
This article explains how improper use of AOP in Spring can cause object escape leading to concurrency safety problems, discusses issues such as asynchronous thread modifications, caching, and incorrect advice ordering with @Transaction, @Retryable, and dynamic datasource switching, and provides practical guidance to avoid these pitfalls.
This article explains the Service Provider Interface (SPI) concept and compares the implementations in Java (ServiceLoader), Spring (SpringFactoriesLoader), and Dubbo (ExtensionLoader), covering their configuration files, core mechanisms, advantages, drawbacks, and typical usage scenarios.
This article explains the concept of retry in distributed systems, introduces Spring Retry and its annotations, demonstrates Maven dependencies, configuration, various retry policies, backoff strategies, circuit breaker support, and walks through the core implementation details with practical code examples.
This article introduces the fundamentals of finite‑state machines, explains the four core concepts of state, event, action and transition, and provides a step‑by‑step Spring Statemachine implementation with database schema, enum definitions, configuration, persistence options, testing, common pitfalls and an AOP‑based solution for reliable transaction handling.
This article explains how to dynamically manage and switch multiple Spring data sources, compares configuration‑file and database‑table approaches, introduces custom DataSource management interfaces, and presents a comprehensive solution for handling multi‑database transactions with custom annotations and AOP.
This article introduces the concept of asynchronous execution and presents eight practical Java implementations—including Thread, Future, CompletableFuture, Spring @Async, ApplicationEvent, message queues, ThreadUtil, and Guava ListenableFuture—along with code examples and usage tips for each method.
This article demonstrates how to create a simple custom annotation that mimics Spring's @Autowired functionality by defining a new annotation, a BeanPostProcessor, configuring beans in XML, and wiring everything together in a test class to show the injection working at runtime.
This article explains the causes of Spring circular dependency exceptions, details how Spring's three‑level cache and AOP proxy mechanisms contribute to the problem, and provides practical solutions such as using @Lazy, refactoring code, and ensuring a single AutoProxyCreator to prevent bean creation failures.
This article explains five ways to add a bean to the Spring IoC container—including @Configuration + @Bean, @Component + @ComponentScan, various @Import techniques, FactoryBean, and BeanDefinitionRegistryPostProcessor—provides complete code examples for each, and concludes with a summary and related promotional notes.
This article explains Spring's transaction propagation behaviors, rollback mechanisms, common pitfalls such as self-invocation, and provides solutions using AOP proxies and @EnableAspectJAutoProxy, supplemented with code examples and a brief promotion of a related community.
This guide explains how to use Spring's @Bean annotation to declare beans, configure dependencies, control lifecycle callbacks, set custom scopes, assign names, aliases, and descriptions, providing Java code examples that parallel equivalent XML configurations.
This article explains Spring's transaction propagation options, rollback mechanisms, the limitations of self‑invocation within @Transactional methods, and how to correctly use AOP proxies such as AopContext.currentProxy() and @EnableAspectJAutoProxy to ensure transactional behavior in Java backend applications.
This article explains how to redesign Spring MVC controllers by introducing a unified Result wrapper, using ResponseBodyAdvice for automatic response packaging, applying JSR‑303 validation on DTOs and method parameters, and handling custom exceptions globally to produce consistent API outputs.
This article explains why traditional Spring MVC Controllers become cumbersome, demonstrates how to unify response structures with a Result wrapper, leverages ResponseBodyAdvice for automatic packaging, resolves String conversion issues, and shows best‑practice parameter validation using JSR‑303, custom validators, and global exception handling to keep controller code clean and maintainable.
This article explores Java multithreading concepts, JVM safety tools, thread creation methods, coordination mechanisms, and practical scenarios such as parallel data aggregation, for‑loop conversion, map‑based processing, and multi‑threaded transaction handling, providing code examples and performance tips for backend developers.
This article explores how Spring implements classic design patterns—Proxy, Strategy, Decorator, Singleton, Simple Factory, Factory Method, Observer, Template, and Adapter—detailing their purpose, core code snippets, and the way Spring leverages them to provide flexible, extensible, and maintainable backend functionality.
This article explains how to refactor a Spring MVC Controller by introducing a unified response wrapper, leveraging ResponseBodyAdvice for automatic packaging, applying JSR‑303 validation for @RequestBody, @PathVariable and @RequestParam parameters, creating custom validation annotations, and handling business and system exceptions consistently.
This article explains the complete lifecycle of a Spring bean—including creation, merged BeanDefinition processing, factory exposure, property population, initialization, and destruction—while illustrating the underlying source‑code mechanisms and how Spring resolves constructors, handles circular dependencies, and integrates AOP and post‑processors.
This article walks through every stage of a Spring Bean's lifecycle—including instantiation, property population, initialization callbacks, usage, and destruction—while providing concrete code examples, execution traces, and an analysis of the underlying Spring source methods.
This article walks through building a Spring @EventListener demo, explains how to decouple registration logic, shows step‑by‑step debugging of the event‑listener infrastructure, and explores the internal mechanisms that register and invoke listeners during application startup and runtime.
This article provides a detailed tutorial on Spring Validation, covering basic dependency setup, requestBody and requestParam/PathVariable validation, advanced techniques such as group, nested, collection and custom validation, programmatic validation, fail‑fast mode, the difference between @Valid and @Validated, and the underlying implementation mechanisms within Spring MVC.
This article explains how to protect time‑consuming business operations using a Redis‑based distributed lock implemented with custom annotations, Spring AOP, and a scheduled thread pool that automatically extends lock expiration to avoid premature release.
This article demonstrates a step‑by‑step implementation of API request throttling in a Spring backend using an Interceptor and Redis, covering the underlying principle, configurable limits, custom annotations, reflection‑based flexibility, and practical considerations such as path parameters and real‑IP handling.
This article introduces Robustdb, a compact open‑source read‑write separation framework built with about ten classes and two thousand lines of code, explains its architecture, routing logic, method‑level transaction handling, dynamic data‑source management, and performance advantages over existing solutions like Atlas.
This article explains Spring's core post‑processor extension points—BeanDefinitionRegistryPostProcessor, BeanFactoryPostProcessor, and BeanPostProcessor—detailing their purpose, execution order, concrete code examples, and how they fit into the bean lifecycle, including advanced interfaces like InstantiationAwareBeanPostProcessor.
This article explains how to use Spring's profile‑specific configuration files, package a multi‑module Java project with Maven or IDEA, and deploy the resulting JAR on a Linux server by installing JDK, setting environment variables, and starting the application in foreground or background.
This article explains the complete Spring bean lifecycle—including creation, property filling, initialization, usage, and destruction—detailing how Spring manages object creation, dependency injection, AOP proxy generation, and lifecycle callbacks through various internal phases and extension points.
This article explains how to dynamically manage multiple Spring data sources, switch them at runtime using AbstractRoutingDataSource, and ensure transactional consistency across databases by implementing custom AOP, connection proxies, and multi‑transaction annotations.
This article explains how to build a clean, maintainable backend API response format by defining a standard JSON wrapper, categorizing status codes, using a Result class with static helpers, and automatically applying the wrapper through a custom @ResponseResult annotation, interceptor, and ResponseBodyAdvice in a Spring‑based service.
This article explains how to dynamically manage multiple Spring data sources, switch between them at runtime, and implement custom multi‑database transaction handling, covering both configuration‑file and database‑table approaches, with code examples and AOP techniques for seamless integration.
This article explains how to refactor a Spring MVC Controller layer by defining its responsibilities, introducing a unified response format, using ResponseBodyAdvice for automatic wrapping, applying JSR‑303 validation for request parameters, and implementing custom exceptions with centralized handling to achieve cleaner, more maintainable backend code.
This article dissects the core bean creation logic of Spring's AbstractAutowireCapableBeanFactory, detailing how createBeanInstance delegates to obtainFromSupplier, instantiateUsingFactoryMethod, autowireConstructor, and fallback default constructors, while explaining the role of Supplier, ConstructorResolver, argument resolution, and caching mechanisms.
This article explains how to replace scattered try‑catch blocks in Java services with a clean, unified exception handling approach using Spring’s @ControllerAdvice, custom Assert interfaces, enum‑based error codes, and standardized response objects to improve readability, maintainability, and internationalized error reporting.
This article explains how to dynamically manage multiple data sources and ensure transactional consistency in Spring applications by extending AbstractRoutingDataSource, using configuration‑file or database‑table approaches, applying AOP for datasource switching, and implementing custom multi‑database transaction management.
This article demonstrates how to prevent abusive API calls in a Spring Boot application by using an Interceptor together with Redis for counting requests, and extends the solution with configurable custom annotations and reflection to allow per‑endpoint rate‑limit settings.
This article explains the concept of finite state machines, outlines scenarios where they are beneficial, compares Spring Statemachine and Squirrel-foundation implementations, and provides detailed configuration, guard/action code, persistence, testing, and practical usage tips for managing complex business workflows in Java backend services.
This article explains the design and implementation of JD's JSF RPC framework, detailing the architecture, XML configuration of providers and consumers, Spring namespace handling, service registration, server startup, client initialization, load balancing, and the overall workflow from provider exposure to consumer invocation.
The article explains how to dynamically manage multiple data sources and ensure transaction consistency in Spring applications by extending AbstractRoutingDataSource, using configuration‑file or database‑table approaches, and applying AOP‑based switching with custom transaction management.
This article explains the principles and differences of the SPI mechanisms in Java, Spring, and Dubbo, covering ServiceLoader, SpringFactoriesLoader, and Dubbo's ExtensionLoader, with detailed demos, core implementation details, advantages, drawbacks, and typical usage scenarios for each framework.
The article explains Spring's three dependency injection methods, highlights the drawbacks of field injection, recommends constructor injection, and demonstrates how Lombok's @RequiredArgsConstructor can generate the required constructor to eliminate @Autowired and @Resource annotations, simplifying code and preventing NullPointerExceptions.
This article explains Spring's three dependency injection methods—field, constructor, and setter injection—highlights the advantages of constructor injection for avoiding null pointers and circular dependencies, and demonstrates how Lombok's @RequiredArgsConstructor can simplify bean wiring in Java backend development.
This article explains how to dynamically manage multiple data sources and ensure transaction consistency across them in Spring applications, covering both configuration‑file and database‑table approaches, custom AOP switching, and a bespoke multi‑database transaction mechanism.
This article explains that while Spring's Validator handles simple parameter validation, it cannot validate relationships between parameters and business data, and demonstrates how using org.springframework.util.Assert provides a more concise, readable way to perform such checks, including exception handling examples.
This article explains how to implement interface rate limiting in a Spring application by creating custom annotations, using AOP for method interception, and leveraging a Redis‑like ConcurrentMap cache to control request counts within a fixed time window.
This article shares fourteen practical Java backend development habits—including using @ConfigurationProperties, replacing @Autowired with @RequiredArgsConstructor, modularizing code, throwing exceptions instead of returning error flags, minimizing unnecessary database calls, avoiding null returns, reducing if‑else chains, and leveraging IDE features—to help developers write cleaner, more robust, and easier‑to‑maintain code.
This article explains why Spring Boot is popular, how @ComponentScan discovers @Component, @Controller, @Service, and @Repository beans across packages, demonstrates usage with code examples, and details the internal processing flow involving ConfigurationClassPostProcessor and related parsers.
