Book Image

Scala Programming Projects

By : Mikael Valot, Nicolas Jorand
Book Image

Scala Programming Projects

By: Mikael Valot, Nicolas Jorand

Overview of this book

Scala Programming Projects is a comprehensive project-based introduction for those who are new to Scala. Complete with step-by-step instructions and easy-to-follow tutorials that demonstrate best practices when building applications, this Scala book will have you building real-world projects in no time. Starting with the fundamentals of software development, you’ll begin with simple projects, such as developing a financial independence calculator, and then advance to more complex projects, such as a building a shopping application and a Bitcoin transaction analyzer. You’ll explore a variety of Scala features, including its OOP and FP capabilities, and learn how to write concise, reactive, and concurrent applications in a type-safe manner. You’ll also understand how to use libraries such as Akka and Play. Furthermore, you’ll be able to integrate your Scala apps with Kafka, Spark, and Zeppelin, along with deploying applications on a cloud platform. By the end of the book, you’ll have a firm foundation in Java programming that’ll enable you to solve a variety of real-world problems, and you’ll have built impressive projects to add to your professional portfolio.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Using exceptions


Exceptions are one of the mechanisms that we can use in Scala to handle error scenarios. It consists of two statements:

  • The throw exceptionObject statement stops the current function and passes the exception up to the caller.
  • The try { myFunc() } catch { case pattern1 => recoverExpr1 } statement catches any exception thrown by myFunc() if the exception matches one of the patterns inside the catch block:
  • If an exception is thrown by myFunc, but no pattern matches the exception, the function stops, and the exception is passed up to the caller again. If there is no try...catch block in the call chain that can catch the exception, the whole program stops.
  • If an exception is thrown by myFunc, and the pattern1 pattern matches the exception, the try...catch block will return the recoverExpr1 expression at the right of the arrow.
  • If no exception is thrown, the try...catch block returns the result returned by myFunc().

This mechanism comes from Java, and since the Scala SDK sits on...