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


In this chapter, you learned the different mechanisms that you can use to work with tasks that return a result. These tasks are based on the Callable interface, which declares the call() method. This is a parameterized interface with the class returned by the call method.

When you execute a Callable task in an executor, you will always obtain an implementation of the Future interface. You can use this object to cancel the execution of the task, know if the task has finished its execution, or get the result returned by the call() method.

You send Callable tasks to the executor using three different methods. With the submit() method, you send one task, and you will immediately get a Future object associated with this task. With the invokeAll() method, you send a list of tasks and will get a list of Future objects when all the tasks have finished their execution. With the invokeAny() method, you send a list of tasks, and you will receive the result (not a Future object) of the first task...