This article explains how to implement the Singleton pattern in Java using both an enum‑based approach and a static inner‑class technique, providing thread‑safe examples from Spring Data JDBC and MyBatis along with Maven dependency snippets and detailed code illustrations.
This article explains how SQL injection can exploit a Java Spring course‑selection system by concatenating user input into SQL statements, demonstrates various injection techniques such as always‑true conditions and UNION queries, and provides multiple defensive measures including prepared statements, type checking, permission restrictions, and request‑parameter filtering.
Explore multiple Spring bean injection techniques—including XML configuration, annotation-driven @Configuration/@Bean, @Import, FactoryBean, and BeanDefinitionRegistryPostProcessor—through clear explanations, code samples, and practical examples, highlighting their advantages, drawbacks, and how to integrate them into a Spring application.
This article demonstrates how to dramatically speed up updating tens of thousands of records in a Spring‑MyBatis application by switching from automatic per‑operation commits to manual transaction control, applying multithreaded processing, tuning the Hikari connection pool, and using SQL UNION‑based batch updates.
This article explains how Spring Kafka’s KafkaMessageListenerContainer and ConcurrentMessageListenerContainer work, details their start-up process and internal consumer threads, shows how @KafkaListener bridges business logic, and provides configuration examples for single‑message and batch processing in Spring Boot.
This article explores twelve practical multithreading use cases in Java, ranging from simple scheduled tasks and listeners to Excel imports, remote call aggregation, user context handling, MDC logging, high‑concurrency simulation, Kafka message processing, atomic counters, and delayed jobs, providing code examples and best‑practice tips for each scenario.
This article discusses practical techniques for Java developers, covering bean conversion using DTOs and Spring utilities, validation with JSR‑303, leveraging Lombok for cleaner code, applying design patterns, and systematic refactoring to improve readability, maintainability, and overall code quality in backend projects.
This article explains the purpose and usage rules of Spring's @Async annotation, compares built‑in executors, demonstrates how to enable @Async, and provides detailed examples of custom thread‑pool configurations, multiple pool management, and important source‑code analysis for robust asynchronous processing in Java backend applications.
This article introduces MapStruct’s new Spring extension, shows how to replace manual BeanUtil conversions with generated mappers, explains the Spring Converter interface, and demonstrates custom configuration and integration with ConversionService for seamless DTO/VO/PO transformations in Java backend projects.
This article explains how to replace manual BeanUtil mapping with MapStruct, leverage Spring's Converter interface, and use the MapStruct Spring Extensions plugin to automatically register mappers with ConversionService, including custom adapter configuration and integration of built‑in Spring converters.
This article explores the concept of fully interface‑based domain modeling, demonstrates how to design domain objects as interfaces, shows repository implementations for JPA, MyBatis and Elasticsearch, discusses association handling, and explains how such designs enable seamless switching between monolithic, clustered and microservice deployments.
This article explains how MapStruct, a Java annotation‑processor library, can automatically generate mapper implementations to convert between entities and DTOs, covering basic usage, default methods, abstract classes, multiple source parameters, update operations, handling fields without getters/setters, Spring injection and custom type conversions.
This article demonstrates how to create a request‑logging aspect in Spring Boot using AOP annotations, shows code for pointcuts, advices, high‑concurrency optimizations, exception handling, and trace‑ID propagation, and explains the underlying concepts and practical tips.
This article provides an in‑depth tutorial on Spring Validation, covering basic usage, dependency setup, requestBody and requestParam validation, DTO constraints, group and nested validation, collection handling, custom validators, programming‑style validation, fail‑fast mode, and the underlying implementation mechanisms in Spring MVC.
This article explores practical Java backend techniques, including IDE selection, domain vs entity naming, DTO conversion strategies with BeanUtils and custom interfaces, validation with JSR‑303, Lombok shortcuts, builder patterns, static constructors, and design‑pattern considerations, offering concrete code examples and refactoring tips for seasoned developers.
Field injection in Spring looks concise, but it introduces hidden dependencies, violates the Single Responsibility Principle, hampers immutability, and tightly couples code to the DI container; the article compares constructor, setter, and field injection, explains their drawbacks, and recommends using constructors for mandatory dependencies and setters for optional ones.
This Spring AOP tutorial explains how to modularize cross‑cutting concerns such as timing by defining an aspect with @Before, @After, @AfterReturning, @AfterThrowing and @Around advice, demonstrates refactoring a calculation service, and compares Spring’s proxy mechanisms to a custom JDK dynamic proxy implementation.
This article explains the background, concepts, and implementation details of Aspect‑Oriented Programming in Java, covering joinpoint interface design, advice abstraction, static and dynamic weaving, and how Spring AOP applies these principles with illustrative code and diagrams.
This article explains how Spring's three‑level cache (singleton, early‑singleton, and singleton‑factory caches) works together with bean post‑processors to break circular dependencies and correctly create AOP proxies, while also showing how to disable circular references when needed.
This article compares native JDK ScheduledExecutorService, Spring Task, Redis‑based approaches, and popular distributed scheduling frameworks such as Quartz, Elastic‑Job, LTS, and XXL‑Job, providing code examples, usage scenarios, advantages, and best‑practice recommendations for implementing reliable timed jobs in microservice environments.
This article explains three common situations where Spring's @Transactional annotation becomes ineffective—non‑public methods, internal self‑calls, and swallowed exceptions—detailing the underlying proxy mechanism, code examples, test results, and practical workarounds to ensure proper transaction management.
This article provides a detailed overview of the most frequently used Spring annotations—including core, MVC/REST, Boot, stereotype, data access, scheduling, and testing annotations—explaining their purposes, usage rules, and providing Java code examples for each.
This article demonstrates how to create a Spring AOP request‑logging aspect that captures IP, URL, HTTP method, class method, parameters, results and execution time, and extends it with high‑concurrency handling, error logging, and TraceId propagation for better traceability.
This article explains how Spring implements broadcast and listener functionality through ApplicationEventPublisher and ApplicationListener, analyzes the underlying bean post‑processor workflow, and provides complete source‑code examples for custom events, publishers, listeners, and a REST client to demonstrate end‑to‑end event handling.
This article explains how to create a Spring AOP request‑logging aspect, covering basic pointcut and advice definitions, parameter extraction, high‑concurrency optimizations with unified JSON logs, exception handling, and adding traceId support for end‑to‑end request tracing.
This article explains how to implement single-node scheduled tasks using JDK's ScheduledExecutorService and Spring @Scheduled, compares Redis‑based approaches with ZSet and key‑space notifications, and reviews popular distributed scheduling frameworks such as Quartz, elastic‑job‑lite, LTS, and XXL‑Job for microservice environments.
This article explores the precise moment a Spring @Transactional transaction is committed relative to a surrounding lock release, revealing that commits occur after the method finishes, and demonstrates how to verify this through source code inspection, debugging techniques, and proper lock‑usage to prevent overselling.
This article explains how to prevent duplicate user requests on the server side by leveraging unique request IDs or business‑parameter MD5 hashes with Redis, provides Java helper utilities, code examples, and practical tips for handling time‑related fields and atomic SETNX operations.
This article presents a design pattern for a unified, annotation‑driven HTTP client in a Spring‑based payment system, detailing custom annotations, dynamic proxy enhancement, and bean registration via FactoryBean and ImportBeanDefinitionRegistrar, with complete code examples and a summary of key concepts.
This article explains three common reasons why the @Transactional annotation may not work in Spring—non‑public methods, self‑invocation, and catching exceptions—provides code examples for each case, and details the underlying proxy and transaction management mechanisms to help developers resolve the issues.
This article details the discovery, official announcement, prerequisite conditions, and step‑by‑step reproduction of the critical Spring Framework remote code execution vulnerability (CVE‑2022‑22965), including exploit payloads, JSP backdoor creation, and practical mitigation insights.
A recent Spring Framework 0‑day remote code execution vulnerability, caused by unsafe use of SerializationUtils#deserialize, affects Java versions above 8, is rated dangerous by security analysts, and highlights the risks of indiscriminate JDK upgrades.
This article compares traditional object creation with Spring’s dependency injection, demonstrating how injecting DAO beans via XML configuration decouples service and data layers, includes Java code examples, test results, and visual analogies of gear systems to illustrate reduced coupling.
This article explains the officially announced Spring Framework remote code execution vulnerability CVE‑2022‑22965, outlines the affected environments, provides upgrade paths for Spring and Spring Boot, and shares safe code‑based mitigation techniques for developers.
This article reveals a newly disclosed Spring framework RCE 0‑day vulnerability caused by unsafe Java serialization, rates it as dangerous, explains why Java 8 remains unaffected, and warns developers against indiscriminate JDK upgrades while comparing it to the Log4j2 incident.
The article investigates the circulating rumors of a massive Spring framework vulnerability, clarifies its actual scope—affecting Java 9+ projects—and explains why the alleged CVE differs from official reports, while warning readers to rely only on verified security advisories.
The author humorously explores a newly disclosed Spring framework RCE 0‑day vulnerability caused by Java serialization, explains why systems running JDK 8 or earlier are unaffected, compares its impact to Log4j2, and warns against indiscriminate JDK upgrades.
This guide explains the Spring SPEL injection flaw, how to determine if your Java application is affected by checking JDK version and Spring usage in WAR or JAR packages, and provides official upgrade steps along with temporary WAF and code‑level mitigations.
This article explains why OpenFeign asynchronous calls fail due to lost request context, demonstrates a RequestInterceptor to propagate JWT tokens, and shows how to capture and set RequestAttributes in CompletableFuture tasks so that async Feign calls succeed without triggering Sentinel degradation.
This article explains the similarities and differences between Spring's @Autowired and the JSR‑250 @Resource annotations, covering their packages, injection mechanisms, usage on fields and setters, configuration options, IDE warnings, and best‑practice recommendations for bean injection in Java backend development.
This article explains the limitations of HTTP for real‑time communication, compares WebSocket with polling, long‑polling, streaming and SSE, outlines WebSocket's benefits and typical use cases, and then details how STOMP complements WebSocket within Spring's messaging framework, including configuration and message flow.
This article provides a comprehensive guide to Spring's most useful utility classes—including Assert, ObjectUtils, StringUtils, CollectionUtils, FileCopyUtils, ResourceUtils, ReflectionUtils, and AopUtils—detailing their purpose, key methods, and practical code examples for backend developers.
This article explains how to standardize API responses in a Spring backend by defining a JSON result structure, designing status codes, using @ResponseResult annotations, interceptors, and controller advice to automatically wrap results, while also discussing optimization and best‑practice considerations.
This article demonstrates how to create a lightweight Spring‑style IoC container in Java by parsing a properties file for XML‑like configuration, implementing annotation‑driven bean registration with a custom @Bean annotation, and adding automatic field injection using a custom @Autowired annotation, complete with full source code examples.
The article breaks down Spring's circular dependency problem, explains its three typical forms, details the three‑level cache mechanism with code snippets, walks through the step‑by‑step resolution process, and lists scenarios where Spring cannot resolve such dependencies.
This article explains Spring's bean lifecycle, the three‑level cache mechanism (singletonObjects, earlySingletonObjects, singletonFactories) used to break circular dependencies, the role of Aware interfaces and BeanPostProcessor, and why a second‑level cache is essential when AOP proxies are involved.
When a Spring @Bean is defined with multiple names, only the first name becomes the bean identifier while the others become aliases that are ignored by type‑based Map injection, causing dynamic data‑source routing to fail unless the aliases are manually added back into the map.
This article explains how to enhance Spring Cache by creating custom cache annotations, replacing the costly KEYS command with SCAN in a rewritten DefaultRedisCacheWriter, and dynamically registering RedisCacheManager beans to support per‑module TTL and transaction‑aware caching, all illustrated with full Java code examples.
This article explains how Spring's @Transactional annotation works by leveraging AOP and dynamic proxies, detailing the bean post‑processor, pointcut definition, proxy creation, interceptor chain, TransactionInterceptor logic, and the transaction commit/rollback process with illustrative code snippets and diagrams.
This roundup covers recent Java ecosystem developments, including the promotion of the Value Objects (Preview) JEP to candidate status, release notes for JDK 18 and early‑access JDK 19 builds, multiple Spring project updates such as Spring Boot 2.7.0‑M1, Spring Data 3.0‑M2 with ListCrudRepository, Spring Security enhancements, as well as Quarkus 2.7.2.Final and a new early‑access version of JReleaser adding Windows resources to jpackage.
This article explains why Spring’s circular dependency problem only occurs with singleton beans, how constructor versus setter injection affects resolution, and why Spring uses a three‑level cache (singletonObjects, earlySingletonObjects, singletonFactories) to expose incomplete beans and support proxy creation without breaking the bean lifecycle.
The article details Meituan's internal Sonic IDEA plugin for remote and local hot deployment, explaining why hot deployment is needed, its architecture, instrumentation techniques, DCEVM integration, file‑watching, class reloading, and support for Spring Bean, Spring XML and MyBatis, along with adoption statistics and performance benefits.
This article explains what streaming queries are, why they save memory compared to pagination, details the MyBatis Cursor interface and its methods, demonstrates how to implement streaming queries with code examples, and presents three solutions—using SqlSessionFactory, TransactionTemplate, and @Transactional—to keep the database connection open and prevent cursor‑closed errors.
This article explains how to modify Spring's @Async annotation so that its value attribute can resolve placeholders or SpEL expressions, demonstrates a working demo, shows the required code changes using EmbeddedValueResolver, and shares debugging tricks and related Java language features.
This article walks through the fundamentals of Spring’s IoC container by manually implementing a lightweight version, covering concepts such as IOC, DI, bean definitions, resource loading, bean registration, and a simple BeanFactory with example code and a test demonstrating singleton caching.
The article sarcastically critiques the over‑engineered nature of enterprise Java projects, illustrating how simple tasks become tangled in excessive classes, interfaces, factories, dependency‑injection frameworks, XML configurations, massive JARs, and IDE bloat, ultimately leading to deployment failures due to environment mismatches.
This article explains why Spring MVC controllers are singleton by default, demonstrates the thread‑unsafe behavior of using instance fields, shows how applying @Scope("prototype") changes the behavior, and provides practical recommendations such as avoiding mutable fields, using prototype scope or ThreadLocal for safe controller design.
This article explains how MyBatis streaming queries work via the Cursor interface, why keeping the database connection open is essential, and presents three practical solutions—using SqlSessionFactory, TransactionTemplate, or @Transactional—to correctly handle streaming data in Spring applications.
Learn how to resolve WebSocket session sharing issues in load‑balanced Java applications by leveraging Redis’s publish/subscribe mechanism and Spring Session, with step‑by‑step configuration, code examples, and deployment instructions for multiple distributed environments.
After upgrading a core component, a previously synchronous domain event in Spring became asynchronous, causing runtime errors; this article explains the underlying mechanism, shows the relevant source code of SimpleApplicationEventMulticaster, and clarifies how the presence or absence of a configured thread pool determines whether events are processed synchronously or asynchronously.
This post shares a comprehensive Java interview handbook containing over 1,000 questions covering MyBatis, Zookeeper, Dubbo, Redis, MySQL, concurrency, Spring, Kafka, micro‑services and more, hosted on GitHub with 30K+ stars, and explains how to obtain the latest PDF via a WeChat QR code.
The article explains that adding Spring Cloud's @RefreshScope annotation to beans annotated with @Service or @Component makes the bean definition synthetic, causing Spring's BeanPostProcessor to skip those beans and leading to processing failures.
The article describes a solution that automatically triggers interface test cases after a service deployment by listening to deployment‑success MQ messages, dynamically invoking TestNG with service‑specific IPs, and integrating Spring bean registration to simplify test code while handling dynamic nodes, reporting, and common pitfalls.
This article explains several often‑confused Spring annotations—including the differences between @Component and @Bean, the injection behaviors of @Autowired versus @Resource, the roles of @Component, @Repository, @Service, and @Controller, the purpose of @Configuration and @ControllerAdvice, and provides practical code examples for each.
This article outlines ten typical concurrency pitfalls in Java—including SimpleDateFormat thread‑safety, double‑checked locking flaws, volatile atomicity limits, deadlocks, lock release issues, HashMap race conditions, default thread‑pool misuse, @Async thread explosion, spin‑lock CPU waste, and ThreadLocal memory leaks—providing explanations, code examples, and practical solutions for each.
This article analyzes a Spring transaction rollback issue caused by the use of pattern‑based exception matching, explains why certain custom exceptions trigger unexpected rollbacks, traces the problem through source code and GitHub issues, and describes how the Spring team fixed it with type‑safe rollback rules and documentation updates.
This article provides a comprehensive analysis of Spring's bean lifecycle, detailing the refresh method steps, post‑processor ordering, bean creation, dependency injection via @Autowired and @Resource, Aware callbacks, and initialization hooks such as @PostConstruct and init‑method.
Spring’s annotation‑based bean registration and dependency injection replace verbose XML by using component scanning with @Component, @Controller, @Service, and @Repository, while @Autowired (or @Qualifier/@Primary) injects beans by type, @Resource supports name‑based injection, and @Value together with @PropertySource loads external configuration, though developers must handle issues such as NoUniqueBeanDefinitionException when multiple candidates exist.
This article explains how to reduce repetitive business‑level Java code by applying the Template Method and Factory patterns, leveraging custom annotations with reflection, and using bean‑mapping utilities, thereby improving maintainability, extensibility, and overall code quality.
Spring Framework 6.x has been officially released, introducing Jakarta EE‑based packages for core annotations, requiring Hibernate‑Core‑Jakarta upgrades, updating servlet containers to Tomcat 10/Jetty 11/Undertow 2.2.14, and altering Web MVC/WebFlux behavior, with detailed migration steps and reference links.
This article explains how to design a dictionary entity, create a custom annotation, and use Spring's ResponseBodyAdvice together with Java reflection to automatically convert enum values to their textual representations in API responses, improving front‑end display without manual mapping.
This tutorial walks through using Spring's RestTemplate to replace complex HttpURLConnection and Apache HttpClient code, covering environment setup, bean configuration, GET/POST/PUT/DELETE operations, file upload/download, and advanced exchange usage with clear Java examples.
This article shares a junior engineer's detailed journey of securing a backend engineering offer at Tencent, covering three interview rounds, key technical topics like Spring, HashMap, Elasticsearch, Redis, and personal reflections on strengths, weaknesses, and preparation strategies.
This article explains how to replace repetitive try‑catch blocks in Java Spring applications with a clean, unified exception handling approach that leverages @ControllerAdvice, custom Assert utilities, enum‑based error codes, and standardized response objects to improve code readability and maintainability.
This article explains how to replace repetitive try‑catch blocks in Java Spring applications with a unified @ControllerAdvice error handler, lightweight Assert utilities, and enum‑based error codes, resulting in cleaner code, consistent JSON responses, and easier maintenance across backend services.
This article explains how to replace repetitive try‑catch blocks in Java Spring applications with a unified exception handling strategy that leverages @ControllerAdvice, custom Assert utilities, and enum‑driven error codes to produce clean, maintainable backend code and consistent error responses.
This article provides a comprehensive reference of Spring Framework utility classes—including Assert, ObjectUtils, StringUtils, CollectionUtils, FileCopyUtils, ResourceUtils, StreamUtils, ReflectionUtils, and AopUtils—detailing their purpose, typical usage scenarios, and full method signatures for Java backend development.
This comprehensive guide walks through Spring's lightweight Java framework, covering its core principles, key features, advantages and drawbacks, the design patterns it employs, core modules, IoC container mechanics, bean scopes, lifecycle, dependency injection techniques, and AOP fundamentals, all illustrated with diagrams and code snippets.
This article explains the inner workings of Spring's @Enable annotations, detailing how @Import processes configuration classes, the roles of ImportSelector and ImportBeanDefinitionRegistrar, and using @EnableAsync as a concrete example to illustrate module activation.
The article explains Spring's warning against field injection, compares constructor‑based, setter‑based, and field‑based dependency injection with code examples, outlines the drawbacks of field injection, and recommends using constructor or setter injection for safer, more maintainable backend Java applications.
Recent Java news highlights early‑access builds of JDK 18 and JDK 19, the 2022 Java roadmap, Spring Framework 5.3.15 and 6.0.0‑M2 releases, Spring Data milestones, Quarkus 2.6.2.Final, Micronaut 3.2.5/3.2.6, Piranha 22.1.0, JobRunr 4.0.6, Eclipse Jifa, Micrometer 2.0.0‑M1 and Tracing 1.0.0‑M1, plus the Foojay mid‑year status report.
This article explains how Spring's bean lifecycle and its three-level caching mechanism—singletonObjects, earlySingletonObjects, and singletonFactories—work together to resolve circular dependencies, especially when AOP proxies are involved, highlighting why a three‑cache approach is necessary.
This article provides a comprehensive overview of Spring Framework’s core utility classes—including Assert, ObjectUtils, StringUtils, CollectionUtils, FileCopyUtils, ResourceUtils, StreamUtils, ReflectionUtils, and AOP helpers—detailing their purpose and key method signatures for developers working on Java backend projects.
This article consolidates frequently used Spring utility classes—such as Assert, ObjectUtils, StringUtils, CollectionUtils, FileCopyUtils, ResourceUtils, ReflectionUtils, and AopUtils—explaining their purpose, typical usage patterns, and providing code snippets to help developers avoid redundant implementations and leverage built‑in Spring functionality.
This article presents a collection of practical Java backend development guidelines, covering configuration management with @ConfigurationProperties, constructor injection via @RequiredArgsConstructor, code modularization, exception handling, database query reduction, null avoidance, strategic use of design patterns, IDE assistance, source code reading, and fundamental coding techniques such as map traversal and collection choice.
This article explains the common Spring AOP annotations such as @Before, @After, @AfterReturning, @AfterThrowing and @Around, demonstrates how to set up a Spring Boot project, write an interface, implementation, aspect, and discusses execution order, multiple aspects, and proxy‑failure scenarios.
This article presents a curated collection of Spring Framework utility classes—including assertion helpers, object/array/collection utilities, file and resource IO tools, as well as reflection and AOP utilities—providing ready‑to‑use methods that replace many custom helper functions in Java backend development.
This article explains the fundamentals of Remote Procedure Call (RPC), detailing the end‑to‑end workflow from defining service interfaces and implementations, registering services in a Zookeeper registry, handling network communication with Netty, and generating client‑side proxies using Spring and JDK dynamic proxies, all illustrated with complete Java code examples.
This article explains how to solve the problem of non‑serializable WebSocket sessions in a load‑balanced Spring application by using Redis publish/subscribe and spring‑session‑redis to share session data across multiple server instances, providing complete configuration and code examples.
This article explains the fundamentals of Remote Procedure Call (RPC), detailing the definition, basic call flow, service interface design, server registration with Zookeeper, Netty-based network communication, dynamic proxy generation on the client side, and provides complete Java code examples for a working RPC framework.
This article explains why lengthy if...else statements in Java payment services violate the Open‑Closed and Single‑Responsibility principles and demonstrates several refactoring techniques—including annotations, dynamic bean naming, template methods, strategy‑factory, and chain‑of‑responsibility patterns—using Spring to eliminate the conditional logic.
This article explains how to guarantee that insert and update messages belonging to the same data entity are consumed in the correct order across separate Kafka topics by applying fine‑grained (or distributed) locks and a cache‑based detection mechanism, complete with Java/Spring code examples.
This article provides a comprehensive guide to Spring's built‑in utility classes—including Assert, ObjectUtils, StringUtils, CollectionUtils, FileCopyUtils, ResourceUtils, StreamUtils, ReflectionUtils, and AOP helpers—explaining their purpose, common methods, and usage examples to replace redundant custom code.
This article explains the fundamentals of Remote Procedure Call (RPC), walks through the complete request‑response flow, and provides a step‑by‑step Java implementation using Spring, custom XML namespaces, Netty for network communication, and Zookeeper for service registration and discovery.
This article explains the Service Provider Interface (SPI) mechanism across JDK, Spring, and Dubbo, showing how to create modular, maintainable code through interface definitions, configuration files, and ServiceLoader or ExtensionLoader usage, with detailed examples, code snippets, and analysis of advantages and drawbacks.
This article explains how to design a Java service that selects the appropriate coupon grant type based on resource type and ID, comparing traditional switch/if‑else, the Strategy pattern, and a concise Map‑lambda approach while showing code examples and trade‑offs.
This article explains Java exception categories, how Spring's @Transactional decides which exceptions trigger a rollback, and provides practical annotation configurations to control rollback behavior for both checked and unchecked exceptions.
This article shares a collection of practical Java backend development habits, covering configuration with @ConfigurationProperties, Lombok's @RequiredArgsConstructor, code modularization, exception throwing, reducing DB queries, avoiding null returns, simplifying if‑else, keeping controllers thin, IDE tips, source code reading, design patterns, and fundamental coding techniques.
This article continues the Spring bean lifecycle series by explaining the property‑assignment stage, Aware interface callbacks, bean initialization phases, and the destruction process, illustrating each step with source‑code diagrams and highlighting how BeanPostProcessor extensions drive the lifecycle.
This article explains Java exception classification, distinguishes checked and unchecked exceptions, and demonstrates how to configure Spring's @Transactional annotation to control rollback behavior, including examples of rollbackFor, notRollbackFor, and propagation settings, while highlighting common pitfalls with try‑catch blocks.
