Книга: Beginning Android

Pieces of Me

Pieces of Me

The simplified model of the construction of a content Uri is the scheme, the namespace of data, and, optionally, the instance identifier, all separated by slashes in URL-style notation. The scheme of a content Uri is always content://.

So, a content Uri of content://constants/5 represents the constants instance with an identifier of 5.

The combination of the scheme and the namespace is known as the “base Uri” of a content provider, or a set of data supported by a content provider. In the previous example, content://constants is the base Uri for a content provider that serves up information about “constants” (in this case, physical constants).

The base Uri can be more complicated. For example, the base Uri for contacts is content://contacts/people, as the contacts content provider may serve up other data using other base Uri values.

The base Uri represents a collection of instances. The base Uri combined with an instance identifier (e.g., 5) represents a single instance.

Most of the Android APIs expect these to be Uri objects, though in common discussion, it is simpler to think of them as strings. The Uri.parse() static method creates a Uri out of the string representation.

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