Book Image

Asynchronous Android Programming - Second Edition

By : Steve Liles
Book Image

Asynchronous Android Programming - Second Edition

By: Steve Liles

Overview of this book

Asynchronous programming has acquired immense importance in Android programming, especially when we want to make use of the number of independent processing units (cores) available on the most recent Android devices. With this guide in your hands you’ll be able to bring the power of Asynchronous programming to your own projects, and make your Android apps more powerful than ever before! To start with, we will discuss the details of the Android Process model and the Java Low Level Concurrent Framework, delivered by Android SDK. We will also guide you through the high-level Android-specific constructs available on the SDK: Handler, AsyncTask, and Loader. Next, we will discuss the creation of IntentServices, Bound Services and External Services, which can run in the background even when the user is not interacting with it. You will also discover AlarmManager and JobScheduler APIs, which are used to schedule and defer work without sacrificing the battery life. In a more advanced phase, you will create background tasks that are able to execute CPU-intensive tasks in a native code-making use of the Android NDK. You will be then guided through the process of interacting with remote services asynchronously using the HTTP protocol or Google GCM Platform. Using the EventBus library, we will also show how to use the Publish-Subscribe software pattern to simplify communication between the different Android application components by decoupling the event producer from event consumer. Finally, we will introduce RxJava, a popular asynchronous Java framework used to compose work in a concise and reactive way. Asynchronous Android will help you to build well-behaved applications with smooth responsive user interfaces that delight the users with speedy results and data that’s always fresh.
Table of Contents (19 chapters)
Asynchronous Android Programming Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
2
Performing Work with Looper, Handler, and HandlerThread
Index

GcmListenerService delivery callbacks


In some situations, when there is no connectivity with the GCM servers due to lack of network connectivity, the message could remain on the local queues for a long period of time. So, in order to discard a message that remains on the queue without being sent to the GCM Service within the time specified, the GoogleCloudMessaging API provides an additional send method that could receive a TTL (Time to Live) time to set the message expire time:

void send (String to, String msgId, long timeToLive, Bundle data)

This works great when you have messages that are only relevant if they arrive within a certain time frame. With a time to live of 0, we'll attempt to send and return an error immediately if we're not connected. This situation does not apply for our example, so we will keep the original code with the send method that does not discard an old unsent message.

It is important to understand that the application GCM client is only able to queue a maximum of...