Make Spring boot application Startup Faster

Question

There are two IOC containers in spring-boot: BeanFactory and ApplicationContext.

As per my understanding, ApplicationContext supports the eager initialization of beans where BeanFactory does it lazily.

Problem Statement: In my Spring boot application, I wanna use lazy initialization of beans to make application startup faster. Can anyone please suggest the solution for achieving the same?

Answer 1

Use lazy initialization property:

spring.main.lazy-initialization=true

This property is only supported in spring boot 2.2 and above. You will need to write a BeanFactoryPostProcessor if version is less than 2.2. This property will make sure that the dependencies are not to be injected until it's needed, the main difference in timing can be seen when hot restart is performed.

FYI ApplicationContext is a BeanFactory, both supports lazy init. It really depends on when BeanFactory#getBeanProvider was invoked.