Android uses content providers for abstracting data into services.
Content providers play a significant role in sharing data between applications.
Content providers makes data sources look like REST-enabled data providers, such as web sites.
To retrieve data from a content provider or save data into a content provider, you will need to use a set of REST-like URIs.
For example, if you were to retrieve a set of books from a content provider that is an encapsulation of a book database, you would need to use a URI like this:
content://com.android.book.BookProvider/books
To retrieve a specific book from the book database, you would need to use a URI like this:
content://com.android.book.BookProvider/books/101
Any application on the device can make use of these URIs to access and manipulate data.
Each content provider on a device registers itself like a web site with a string called an authority.
The authority string forms the basis of a set of URIs that this content provider can offer.
This authority registration is defined in the AndroidManifest.xml file.
Here are two examples of how you can register providers in AndroidManifest.xml:
<provider android:name="SomeProvider" android:authorities="com.your-company.SomeProvider" /> <provider android:name="NotePadProvider" android:authorities="com.google.provider.NotePad"/>
An authority is like a domain name for that content provider.
A content provider, like a web site, has a base domain name that acts as a starting URL.
Given the preceding authority registration, these providers will take URLs starting with that authority prefix:
content://com.your-company.SomeProvider/ content://com.google.provider.NotePad/
The providers offered by Android may not have a fully qualified authority name.
For example, contacts as opposed to com.google.android.contacts.
Content-provider abstraction is required only if you want to share data externally or between applications.
For internal data access, an application can use the following: