Book Image

Learn Spring for Android Application Development

By : S. M. Mohi Us Sunnat, Igor Kucherenko
Book Image

Learn Spring for Android Application Development

By: S. M. Mohi Us Sunnat, Igor Kucherenko

Overview of this book

As the new official language for Android, Kotlin is attracting new as well as existing Android developers. As most developers are still working with Java and want to switch to Kotlin, they find a combination of these two appealing. This book addresses this interest by bringing together Spring, a widely used Java SE framework for building enterprise-grade applications, and Kotlin. Learn Spring for Android Application Development will guide you in leveraging some of the powerful modules of the Spring Framework to build lightweight and robust Android apps using Kotlin. You will work with various modules, such as Spring AOP, Dependency Injection, and Inversion of Control, to develop applications with better dependency management. You’ll also explore other modules of the Spring Framework, such as Spring MVC, Spring Boot, and Spring Security. Each chapter has practice exercises at the end for you to assess your learning. By the end of the book, you will be fully equipped to develop Android applications with Spring technologies.
Table of Contents (13 chapters)

Null safety, reflection, and annotations

Although we have already covered the most common topics that relate to a basic overview of Kotlin, there are a few more topics that have to be touched upon.

This section will introduce the following topics:

  • Null safety
  • Reflection
  • Annotations

Null safety

Kotlin supports a more strict type system when compared to Java, and divides all types into two groups, as follows:

  • Nullable
  • No-nullable

One of the most popular causes of an app crashing is the NullPointerException. This happens as a result of accessing a member of a null reference. Kotlin provides a mechanism that helps us to avoid this error by using a type system.

The following diagram shows what the class hierarchy looks like...