Whether you are Android beginner developer or an Android seasoned programmer, this book will explore how to achieve efficient and reliable multithreaded Android applications.
We'll look at best asynchronous constructs and techniques, commonly used by Android Developer community, to execute computation intensive or blocking tasks off the main thread, keeping the UI responsive, telling the user how things are going, making sure we finish what we started, using those powerful multicore processors, and doing it all without wasting the battery.
By using the right asynchronous construct, much of the complexity is abstracted from the developer, making the application source code more readable and maintainable and less error prone.
Using step-by-step guidelines and code examples, you will learn how manage interactions between several threads and avoid concurrency and synchronization problems that might occur when two or more threads access a shared resource to complete a background job, to update the UI or retrieve the latest application data.
At the end of this journey you will know how build well-behaved applications with smooth, responsive user-interfaces that delight users with speedy results and data that's always fresh.
Chapter 1, Asynchronous Programming in Android, gives an overview of the Android process and thread model, and describes some of the challenges and benefits of concurrency in general, before discussing issues specific to Android.
Chapter 2, Performing Work with Looper, Handler and HandlerThread details the fundamental and related topics of Handler, HandlerThread, and Looper, and illustrates how they can be used to schedule tasks on the main thread, and to coordinate and communicate work between cooperating background threads.
Chapter 3, Exploring the AsyncTask, covers the most common concurrent construct of programming in Android. We learn how AsyncTask works, how to use it correctly, and how to avoid the common pitfalls that catch out even experienced developers.
Chapter 4, Exploring the Loader, introduces the Loader framework and tackles the important task of loading data asynchronously to keep the user interface responsive and glitch free.
Chapter 5, Interacting with Services, we explored the very powerful Service Android component, putting it to use to execute long-running background tasks with or without a configurable level of concurrency. This component gives us the means to perform background operations beyond the scope of a single Activity lifecycle and to ensure that our work is completed even if the user leaves the application.
Chapter 6, Scheduling Work with AlarmManager, introduces to us a system API that could be used to defer work or create periodic tasks. The scheduled task could wake up the device to complete the work or alert users to new content.
Chapter 7, Exploring the JobScheduler API, covers a job scheduling system API introduced with Android Lollipop that allows us to start background work when a set of device conditions, such as energy or network, are fulfilled.
Chapter 8, Interacting with the Network, we cover in detail HttpUrlConnection Android HTTP client. With the HttpUrlConnection HTTP client, we will create an asynchronous toolkit that is able to fetch JSON documents, XML or text from a remote server.
Chapter 9, Asynchronous Work on the Native layer, introduces the JNI interface, an Java standard interface that will allow us to execute concurrent tasks on native code (C/C++), interact with the Java code from the native layer or update the UI from the native code.
Chapter 10, Network Interactions with GCM, we will learn how to use the Google GCM to efficiently push and pull efficiently realtime messages from your server and how to schedule work with Google Play Services framework.
Chapter 11, Exploring Bus-based Communications, we will introduce to the reader the publish-subscribe messaging pattern and the Event Bus Library, a publish-subscribe implementation that allow us to deliver asynchronous messages between Android application components.
Chapter 12, Asynchronous Programing with RxJava, we will introduce RxJava, a library used to easily compose asynchronous and event-based tasks on Java by using observable data streams.
To follow along and experiment with the examples, you will need a development computer with a Java 7 (or 8) SE Development Kit and the Android Software Development Kit Version 9 or above (you will need at least Version 21 to try all of the examples).
You will also need Android Studio IDE. The examples have been developed using Google's new Android Studio IDE and use its integrated build system, Gradle.
While you can run the examples using the emulator provided by the Android SDK, it is a poor substitute for the real thing. A physical Android device is a much faster and more pleasurable way to develop and test Android applications!
Many of the examples will work on a device running any version of Android since 2.3, GingerBread. Some examples demonstrate newer APIs and as a result, require a more recent Android version—up to Android 5, Lollipop.
This book is for Android Developers who want to learn how to build multithreaded and reliable Android applications using high level and advanced asynchronous techniques and concepts.
They want to learn this technology because they want learn how to build efficient applications that are able to interact orderly with internal/external services and frameworks using Android standard constructs and APIs.
No prior knowledge of of concurrent and asynchronous programming is required. This book is also targeted towards Java experts who are new to Android.
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exten => s,2,Voicemail(u100)
exten => s,102,Voicemail(b100)
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