Android Application Development For Dummies, 2nd Edition

Finding Places to Put Data

Depending on the requirements of your application, you may need to store data in a variety of places. For example, if an application interacts with music files and a user wants to play them in more than one music program, you have to store them in a location where all applications can access them. An application that needs to store sensitive data, such as encrypted usernames and password details, shouldn’t share data — placing it in a secure, local storage environment is the best strategy. Regardless of your situation, Android provides various options for storing data.

Viewing your storage options

The Android ecosystem provides various locations where data can be persisted:

Shared preferences: Private data stored in key-value pairs. (See Chapter 15 to find out how to handle shared preferences.)

Internal storage: A location for saving files on the device. Files stored in internal storage are private to your application by default, and other applications cannot access them. (Neither can the user, except by using your application.) When the application is uninstalled, the private files are deleted as well.

Local cache: The internal data directory for caching ...