Kernel · IoC Container
BeanDefinition, the twelve steps of refresh(), bean lifecycle and the three-level cache — the IoC container taken apart.
5 tutorials
01IoC and DI Explained: What Exactly Gets InvertedStarting from order code that explodes on every change: the three readings of IoC, three injection styles, DIP and the Hollywood Principle — the cornerstone for everything else in the kernel.Intermediate38′02BeanDefinition in Detail: The Registry Behind Every BeanA container manages definitions, not objects. Walk every core field of BeanDefinition, its three registration sources, parent merging and the exact moment post-processors rewrite it.Intermediate40′03The Boot Kernel: All Twelve Steps of refresh()Behind one line — new AnnotationConfigApplicationContext() — sit twelve precise steps. Walk every step of refresh(), its extension points and its source locations to see what really happens at startup.Advanced34′04The Complete Bean Lifecycle: From Instantiation to DestructionA bean passes eight phases and five callback types from birth to death. Each phase comes with source order and runnable verification — plus the classic question: at which step is the AOP proxy created?Advanced47′05Circular Dependencies and the Three-Level CacheA needs B and B needs A — why is Spring calm? The lookup order of the three caches, how early references get promoted, and the classic question of why three levels instead of two.Advanced44′