ThinkerQAQ

NOTE

Spring Bean Lifecycle

From bean definition and instantiation through dependency injection, post-processors, initialization, proxies, use, and destruction.

JavaCreated Updated 1 min readhistorical

This is a historical learning note and may contain outdated or incomplete understanding.

A useful high-level Spring bean lifecycle is:

  1. bean definition is registered/merged;
  2. bean instance is created;
  3. dependencies/properties are populated;
  4. awareness callbacks and BeanPostProcessor hooks run;
  5. initialization callbacks run;
  6. post-processors may return a wrapped/proxy object;
  7. the bean is used;
  8. managed destruction callbacks run when the owning context closes.

Exact hook ordering has version-specific details. The important design point is that framework post-processors can participate before/after initialization and can replace the exposed object with a proxy.