Multiple PostConstruct methods?

Question

It says in Java's documentation page for PostConstruct that

Only one method can be annotated with this annotation

But I just tried annotating three methods of a standalone application with PostConstruct. No compile errors, and all three of them are invoked and executed smoothly.

So what am I missing? In what kind of class can and cannot exist multiple PostConstruct annotations?

Answer 1

Yes, it's seem Spring doesn't follow this restriction. I have found code to process this annotation which is InitDestroyAnnotationBeanPostProcessor, and the specific method:

public void invokeInitMethods(Object target, String beanName) throws Throwable {         Collection<LifecycleElement> initMethodsToIterate =                 (this.checkedInitMethods != null ? this.checkedInitMethods : this.initMethods);         if (!initMethodsToIterate.isEmpty()) {             boolean debug = logger.isDebugEnabled();             for (LifecycleElement element : initMethodsToIterate) {                 if (debug) {                     logger.debug("Invoking init method on bean '" + beanName + "': " + element.getMethod());                 }                 element.invoke(target);             }         }     } 

So, spring support multi PostConstruct