Content Provider

UI Code is directory interacting with database

CatalogActivity ->
EditorActivity -> Content Provider -> PetDbHelper (Pet with ID 1 has weight 7)

Manage access to a structured set of data
-good abstraction layer between data source & UI code (can add data validation, can modify how data is stored UI code is unaffeted)
-work well with other Android framework classes

UI code
Catalog Activity, Content Resolver, Pet Provider, PetDbHelper SQLiteDatabase

Contacts provider
content://com.android.contacts/contacts
Calendar provider
content://com.android.calendar/events
User Dictionary provider
content://user_dictionary/words

Scheme, Content Authority, Type of data

content authority

<provider
	android:name=".data.PetProvider"
	android:authorities="com.example.android.pets"
	android:exported="false" />

int match = sUriMatcher.match(uri);
if (match == CONTACTS){
	// Act on the contacts table
} else if (match == CONTACTS_ID){
	// Act on a single contact in contacts table
}

public class PetProvider extends ContentProvider {

	private static final int PETS = 100;
	private static final int PET_ID = 101;

	private static final UriMatcher sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
	static {
		sUriMatcher.addURI(PetContract.CONTENT_AUTHORITY, PetContract.PATH_PETS,PETS);
		sUriMatcher.addURI(PetContract.CONTENT_AUTHORITY,PetContract.PATH_PETS + ""/, PETS_ID);
	}
	...
}