What does @PostConstruct do

In the vernacular :
@PostConstruct

	从Java EE5规范开始，Servlet中增加了两个影响Servlet生命周期的注解，
	@PostConstruct和@PreDestroy，这两个注解被用来修饰一个非静态的void（）方法。写法有如下两种方式：

@PostConstruct
public void someMethod(){
    
    }

or

public @PostConstruct void someMethod(){
    
    }

The method decorated by @PostConstruct will run when the server loads the Servlet, and will only be executed once by the server. PostConstruct is executed after the constructor and before the init() method.

Annotate a method with @PostConstruct to complete initialization, and the method annotated with @PostConstruct will be automatically called after dependency injection is completed.

tips:
The sequence of Constructor, @Autowired, and @PostConstruct in spring
Constructor >> @Autowired >> @PostConstruct