Spring before the bean is initialized, before the beans are destroyed

　Before Spring initializes the bean, there are three ways to do it after the bean is destroyed:

1. The operation that was performed prior to initialization through @postconstruct, @PreDestroy implementation before destroying the bean

2. By defining the Init-method and Destory-method methods in XML

3. Implement Initializingbean and Disposablebean through beans

@PostConstruct description

The method that is modified by @postconstruct will run when the server loads the servlet and will only be called once by the server, similar to the Serclet Inti () method. methods that are modified by @postconstruct will run before the Init () method after the constructor.

@PreConstruct description

The @preconstruct-modified method runs when the server unloads the servlet and is only called once by the server, similar to the Destroy () method of the servlet. methods that are modified by @preconstruct are run after the Destroy () method, before the servlet is completely uninstalled.

Spring before the bean is initialized, before the beans are destroyed