Book Image

Mastering Concurrency Programming with Java 9 - Second Edition

By : Javier Fernández González
Book Image

Mastering Concurrency Programming with Java 9 - Second Edition

By: Javier Fernández González

Overview of this book

Concurrency programming allows several large tasks to be divided into smaller sub-tasks, which are further processed as individual tasks that run in parallel. Java 9 includes a comprehensive API with lots of ready-to-use components for easily implementing powerful concurrency applications, but with high flexibility so you can adapt these components to your needs. The book starts with a full description of the design principles of concurrent applications and explains how to parallelize a sequential algorithm. You will then be introduced to Threads and Runnables, which are an integral part of Java 9's concurrency API. You will see how to use all the components of the Java concurrency API, from the basics to the most advanced techniques, and will implement them in powerful real-world concurrency applications. The book ends with a detailed description of the tools and techniques you can use to test a concurrent Java application, along with a brief insight into other concurrency mechanisms in JVM.
Table of Contents (21 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback

Chapter 5. Getting Data from Tasks - The Callable and Future Interfaces

In Chapter 3, Managing Lots of Threads - Executors, and Chapter 4, Getting the Most from Executors, we introduced the Executor framework to improve the performance of concurrent applications and showed you how to implement advanced characteristics to adapt this framework to your needs. In these chapters, all the tasks executed by the executor were based on the Runnable interface and its run() method that doesn't return a value. However, the Executor framework allows us to execute other kinds of tasks that return a result based on the Callable and Future interfaces. Callable is a functional interface which defines the method call(). The method call() may throw a checked Exception which is different to the Runnable interface. The result of a Callable interface process is wrapped by the Future interface. The Future represents the result of asynchronous computation. In this chapter, we will cover the following topics:

  • An...