RESTful APIs:

This is an Implementation of the Cloud Native Java Book - Chapter 6. best RESTful apis tends to exploit more HTTP's capabilities.

Leonard Richardson Maturity Model:

• Level 0: Describes APIs that uses HTTP as a transport protocol and nothing more.
• Level 1: Describes APIs that use multiple URIs to distinguish related nouns. but otherwise avoid the full features of HTTP.
• Level 2: Describes APIs that leverage transport-native properties (LIKE HTTP verbs, status codes) to enhance the service. NOTE: of you do everything incorrectly with Spring MVC you still end up with an API that's Level 2 compliant.
• Level 3: Describes APIs that require no a prior knowledge of a service in order to navigate it - HATEOAS.

Content Negotiation:

Content Negotiation is one of the most powerful features of HTTP: the same service may serve clients that accept different protocols.

Little Bite of Servlet Container Terminology:

In a typical Servlet Container implementation (Like Apache tomcat, ...) each http request is handled via a thread that is obtained from that Servlet Container's thread pool.

Threads pool are necessary to control the amount of the threads that are being executed simultaneously.

In a regular basis, each thread consumes ~1MB of memory just to allocate a single thread stack, 
so 1000 simultaneous requests could use ~1GB of memory only for the thread stacks. Therefore, 
thread pool comes as a solution to limit the amount of threads being executed, fitting the application
to a scenario where it doesn’t throw an OutOfMemoryError.

Error Handling:

@ControllerAdvie is a special type of component that may introduce behavior (and respond to exceptions) for any number of controllers. They are natural place to stick centralized @ExceptionHandler handlers.

Useful Resources:

• Using Asynchronuous Calls With Spring MVC