Full-stack Java development with Vue 2/3 front-end suite; hands-on examples and source code analysis for Spring, Spring Boot 2/3, and Spring Cloud.
This article introduces CompletableFuture, explains its core features and ideal use cases, and provides 50 practical Spring Boot 3 examples covering simple async tasks, chaining, exception handling, timeouts, custom thread pools, HTTP requests, and advanced composition techniques.
This article demonstrates how to extend Spring Boot 3's dependency injection to objects created with the new operator by using AspectJ load‑time weaving, @Configurable, META‑INF/aop.xml configuration, and the required -javaagent, providing step‑by‑step code examples and troubleshooting tips.
This article explains why defensive programming is crucial for production‑grade Spring Boot 3 applications and presents eight concrete patterns—ranging from Optional‑based NPE safety and collection handling to configuration validation, async management, transaction control, testing, exception handling, circuit‑breaker integration, and reactive programming—each illustrated with real‑world code examples and best‑practice recommendations.
This article introduces the Smart-Doc tool for Spring Boot, explains why API documentation is essential, compares common documentation solutions, and provides step‑by‑step instructions—including Maven plugin configuration, JSON settings, command‑line generation of HTML, Markdown, Word, Postman and OpenAPI formats, as well as package exclusion and additional options.
This article explains the powerful flatMap operator in Java streams, covering basic usage, Optional handling, replacing nested loops, API response flattening, combining with filter, reactive programming, and a comprehensive end‑to‑end example, all illustrated with Spring Boot 3 code snippets.
This article examines the @Transactional annotation in Spring Boot, explains its proper and improper use, and presents extensive performance tests using JPA, JDBC, and EntityManager that reveal surprising cases where transactions improve query throughput.
This article explains how to use Spring WebFlux's WebClient for HTTP calls, demonstrates basic retry, backoff, custom retry logic, jitter to avoid retry storms, and integrates circuit breakers with Resilience4j to build resilient Spring Boot 3 applications.
This article explains the purpose and usage of Spring Boot’s @PostConstruct and @PreDestroy annotations for bean initialization and cleanup, discusses their migration to Jakarta EE in Spring Boot 3+, and presents modern alternatives such as @EventListener with ApplicationReadyEvent, DisposableBean, and destroyMethod configurations, complete with code examples.
This article introduces nine often‑overlooked Spring Boot 3 annotations—including @ConditionalOnExpression, @ConstructorBinding, @EventListener, @Lazy, @EnableConfigurationProperties, @Profile, @Scheduled, @Scope, and @Retryable—explaining their purpose, showing practical code examples, and demonstrating how they improve configuration, immutability, event handling, circular‑dependency resolution, and fault tolerance.
This article demonstrates how to accelerate Spring Batch jobs in Spring Boot 3 by comparing a default synchronous job with asynchronous processing using ThreadPoolTaskExecutor and then with virtual threads, providing code examples, configuration steps, and performance results that show up to a 90‑fold speedup.
