@PostConstruct annotation and spring lifecycle
If you are asking is injection of given class happening after @PostConstruct
in that bean is called, then the answer is yes - @PostConstruct
is executed before bean is considered as "injectable"
If you are asking if @PostConstruct
on given bean is executed after all injections has been done (on the same bean) - then yes - @PostConstruct
is executed after injections are commited to given bean. This is the reason it exists. Normally you could put @PostConstruct
actions into the constructor. However, when new object is created (constructor is called) injections are not performed yet - so any initialization that depends on injected objects would fail due to NPE. That is why you need @PostConstruct
The handling of annotations such as @PostConstruct
, @Resource
, @PreDestroy
is done via a BeanPostProcessor, in this case the CommonAnnotationBeanPostProcessor. You can see in the following diagram from Spring that these BPP's are handled after Dependency Injection but before Bean Ready For Use
(Which means as much as injectable).