On-the-fly DB reconfiguration in Spring Boot application

Question

I have quite a complex Spring Boot application (including Spring MVC and Security), which among other things requires a database configuration (url, username and password). The requirement is to let end-user configure the DB with the help of the application itself, like the following:

1. User starts the application, which has no DB configuration yet
2. Application notices the absence of DB configuration and presents user with configuration screen
3. User enters url and credentials
4. Application starts using this DB

The obvious problem is that I cannot create any beans that require a DataSource which requires DB configuration until that configuration is known.

Is there any way to postpone the initialisation of the majority of the application's beans until first configuration step is performed?

-- Update -- Several of application's beans initialise their state from the DB in their @PostConsutrct methods. So I either need to really delay their creation or have a method of refreshing (potentially) all beans in the application context after configuration is provided.

Answer 1

I suggest you could think about having another module/program or a simple script that would ask to provide all details like database etc, store this information to your application.properties file (may be useful re externalized configuration Spring boot external configuration) and then launch your main program with already available information on datasource. This might be a bit easier approach.