Book Image

Design Patterns and Best Practices in Java

By : Kamalmeet Singh, Adrian Ianculescu, Lucian-Paul Torje
Book Image

Design Patterns and Best Practices in Java

By: Kamalmeet Singh, Adrian Ianculescu, Lucian-Paul Torje

Overview of this book

Having a knowledge of design patterns enables you, as a developer, to improve your code base, promote code reuse, and make the architecture more robust. As languages evolve, new features take time to fully understand before they are adopted en masse. The mission of this book is to ease the adoption of the latest trends and provide good practices for programmers. We focus on showing you the practical aspects of smarter coding in Java. We'll start off by going over object-oriented (OOP) and functional programming (FP) paradigms, moving on to describe the most frequently used design patterns in their classical format and explain how Java’s functional programming features are changing them. You will learn to enhance implementations by mixing OOP and FP, and finally get to know about the reactive programming model, where FP and OOP are used in conjunction with a view to writing better code. Gradually, the book will show you the latest trends in architecture, moving from MVC to microservices and serverless architecture. We will finish off by highlighting the new Java features and best practices. By the end of the book, you will be able to efficiently address common problems faced while developing applications and be comfortable working on scalable and maintainable projects of any size.
Table of Contents (15 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Schedulers


Observables are agnostic in terms of thread scheduling–in a multithreading environment, this is the job of a scheduler. Some of the operators presented variants that can take a scheduler as a parameter. There are specific calls that allow observing the flow either from downstream (the point where the operator is used, this is the case of observeOn) or irrespective of call position (the call position does not matter, as this is the case of the subscribeOn method). In the following example, we will print the current thread from upstream and downstream. Notice that in the case of subscribeOn, the thread is always the same:

Notice the thread main usage from the map method:

Notice that the thread main is no longer used from the map method.

RxJava 2.0 offers more schedulers available from the io.reactivex.schedulers.Schedulers factory, each one serving a specific purpose:

  • computation(): Returns a Scheduler instance intended for computational work
  • io(): Returns a Scheduler instance intended...