In this post, we will develop a simple Patient Management System using Spring Boot (spring-data-jpa), where the patient information is stored in a MySQL database and the medical record stored in a PostgreSQL database. The developed application should interact with both databases in real time and perform various database operations.

When a RESTful API returns a pageable result, it is a good practice to return the required pagination links to enable the clients to easily navigate all the available resources.

In this post, we will look at how to achieve this using PagedResourcesAssembler.

Spring data provides the org.springframework.data.web.PagedResourcesAssembler class which is an implementation ofRepresentationModelAssembler, PagedModel>> interface.

A software application is said to be RESTful if the engine of the application state is driven by hypertext (hypermedia). which means that it allows an extensive cross referencing between related data and ensures further operations will depend on the state of the resource.

In software engineering, traditionally, a custom piece of code controls its call to a reusable code or framework, however, with Inversion of control (IoC), it is the framework that calls into the custom piece of code

Inversion of control (IoC) is sometimes referred to as the "Hollywood Principle: Don't call us, we'll call you".  This implies that the application code does not control the creation of its dependencies.