So far, we have prepared you to become a professional Spring-based developer. You have learned what Spring is, as well as the functions of its architecture, components, security features, database, and so on. We have also shown you how to develop an Android app and handle HTTP requests and use the database. 

As you know, we developed all the example projects in Kotlin, and nowadays, this language is very famous among developers for its conciseness and interoperability. In this chapter, we will implement all the features of the previous chapters to develop a project that will have a server and a client side. 

This chapter covers the following topics:

• Project idea
• Creating the design
• Server side:
  • Developing a database model
  • Creating a project and Maven dependency
  • Creating entities, repositories, and a controller
  • Implementing security
  • Modified application.properties
• Client side:
  • Creating models
  • Creating HTTP requests
  • Creating API services
  • Modifying activities
  • Fetching REST APIs
  • Creating an adapter and XML layouts
  • Checking the output