Chapter 5. Queuing Work with IntentService

We're building up quite a toolkit for asynchronous Android programming. We can perform work off the main thread and update the user interface using HandlerThread and Handler. If we're working in the context of a single Activity and want to show progress as we go, we can use AsyncTask. When we need to load data asynchronously and have it survive across Activity restarts, we can turn to Loaders.

What if we want to perform some background work that must complete even if the user exits the application?

Applications usually don't get killed immediately by the system, so we could just start a background thread and hope that the system doesn't kill our application before the work is completed.

However, this would be quite unreliable, and we can be sure that it won't work well on a large percentage of Android devices in the wild. Luckily, there is a solution available in the form of Service and its more specialized subclass IntentService.

In this chapter, we...