[resteasy] Migrating existing Rest Easy Project to SpringBoot

Team, I am trying to integrate my existing project from RestEasy implementation to SpringBoot 2.x My current project settings has two application classes(javax.ws.rs.core.Application): App1 and App2 Three Provider Classes: P1, P2 and P3 The providers are registered to the applications as follows: App1 --> P1, P2 App2 --> P1, P3 Applications are registered by updating the singletons set in the Application Constructors of App1 and App2. Example: public App1{ singletons.add(new P1()); singletons.add(new P2());} I was referencing the RestEasy - SpringBootStarter :https://github.com/resteasy/resteasy-spring-boot/blob/main/mds/USAGE.md. Had the following questions after reading the description: 1. I do not see the use of such singletons recommended anymore. So how do I ensure, that the Providers are registered to the correct Application? 2. How do i convert the context param, filter-mapping, login-config, security constraint configurations defined in web.xml to the equivalent SpringBoot configurations that would work with Rest Easy. 3. What has more precedence the SpringBoot Security modules or the RestEasy security constraints?