Tutoriel Android : Apprendre à utiliser un fournisseur de contenu avec les ContentProvider

//Récupérer la liste des contacts
Cursor cursor = getContentResolver().query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
while (cursor.moveToNext()) {
    String contactId = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts._ID));
    String hasPhone = cursor.getString(cursor.getColumnIndex(ContactsContract.
        Contacts.HAS_PHONE_NUMBER));
    if (Boolean.parseBoolean(hasPhone)) {
        // You know have the number so now query it like this
        Cursor phones = getContentResolver().query(
            ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,
            ContactsContract.CommonDataKinds.Phone.CONTACT_ID + " = " + contactId, null, null);
        while (phones.moveToNext()) {
            String phoneNumber = phones.getString(phones
                .getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
        }
        phones.close();
    }

    Cursor emails = getContentResolver().query(
        ContactsContract.CommonDataKinds.Email.CONTENT_URI, null,
        ContactsContract.CommonDataKinds.Email.CONTACT_ID + " = " + contactId, null, null);
    while (emails.moveToNext()) {
        // This would allow you get several email addresses
        String emailAddress = emails.getString(emails
            .getColumnIndex(ContactsContract.CommonDataKinds.CommonDataColumns.DATA));
    }
    emails.close();
}
cursor.close();

Cursor people = getContentResolver().query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
while (people.moveToNext()) {
    int nameFieldColumnIndex = people.getColumnIndex(PhoneLookup.DISPLAY_NAME);
    String contact = people.getString(nameFieldColumnIndex);
    int numberFieldColumnIndex = people.getColumnIndex(PhoneLookup.NUMBER);
    String number = people.getString(nameFieldColumnIndex);
}
people.close();

private String getNote(long contactId) {
    String note = null;
    String[] columns = new String[] { ContactsContract.CommonDataKinds.Note.NOTE };
    String where = ContactsContract.Data.RAW_CONTACT_ID + " = ? AND " + ContactsContract.Data.MIMETYPE + " = ?";
    String[] whereParameters = new String[] { Long.toString(contactId), ContactsContract.CommonDataKinds.Note.CONTENT_ITEM_TYPE };
    Cursor contacts = getContentResolver().query(ContactsContract.Data.CONTENT_URI, projection, where, whereParameters, null);
    if (contacts.moveToFirst()) {
        note = contacts.getString(0);
    }
    contacts.close();
    return note;
}

Uri media = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String[] projection = { MediaStore.Audio.Media._ID,           // 0
                        MediaStore.Audio.Media.ARTIST,        // 1
                        MediaStore.Audio.Media.TITLE,         // 2
                        MediaStore.Audio.Media.ALBUM_ID,      // 3
                        MediaStore.Audio.Media.ALBUM,         // 4
                        MediaStore.Audio.Media.DATA,          // 5
                        MediaStore.Audio.Media.DISPLAY_NAME,  // 6
                        MediaStore.Audio.Media.DURATION };    // 7
 
String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";
 
Cursor cursor = query(c,media,projection,selection,null,null);
while(cursor.moveToNext()){
     songs.add(new Music(cursor.getString(1),
                         cursor.getString(2),
                         cursor.getString(4),
                         cursor.getString(7),
                         cursor.getString(5),
                         cursor.getLong(0),
                         cursor.getLong(3)));
}
return songs;

public class MyDataProvider extends ContentProvider {
    // Mon Authority, mes paths to data et mon URI
    // The Authority
    public static final String AUTHORITY = "myAuthority";//package de la classe provider est préconisé (utilise des .)
    // The path to the data… and explain 
    public static final String PATH_TO_DATA = "myPath"; //Vous pouvez déclarer plusieurs paths (les paths utilisent les /)

    // This class aims to show the constant to use for the MyDataProvider

    public class MyDatas extends BaseColumns {

        // The URI and explain, with example if you want 
        public static final URI CONTENT_URI = URI.parse("content://" + MyDataProvider.AUTHORITY + "/" + MyDataProvider.PATH_TO_DATA);

        // Mon MIME type
        // My Column ID and the associated explanation 
        public static final String MIME_COLLECTION = "vnd.android.cursor.dir/vnd.myCompany.contentType"

        // My Column ID and the associated explanation
        public static final String MIME_ITEM = "vnd.android.cursor.item/vnd.myCompany.contentType"

        // Noms de colonnes
        //  /!\Si vous utilisez une base de données, les noms des colonnes sont les mêmes que ceux de votre base, de même pour les index.

        // My Column ID and the associated explanation for end-users
        public static final String KEY_COL_ID = "_id"; // Mandatory

        // My Column Name and the associated explanation for end-users 
        public static final String KEY_ COL_NAME = "name";

        // My Column First Name and the associated explanation for end-users 
        public static final String KEY_ COL_FIRSTNAME = "firstName";

        // My Column Eyes Color and the associated explanation for end-users 
        public static final String KEY_ COL_EYES_COLOR = "eyesColor";

        // My Column Hair color and the associated explanation for end-users 
        public static final String KEY_ COL_HAIR_COLOR = "hairColor";

        // My Column age and the associated explanation for end-users 
        public static final String KEY_ COL_AGE = "age";

        // Index des colonnes

        // The index of the column ID
        public static final int ID_COLUMN = 1;
        // The index of the column NAME
        public static final int NAME_COLUMN = 2;
        // The index of the column FIRST NAME
        public static final int FIRSTNAME_COLUMN = 3;
        // The index of the column EYES COLOR
        public static final int EYES_COLOR_COLUMN = 4;
        // The index of the column HAIR COLOR
        public static final int HAIR_COLOR_COLUMN = 5;
        // The index of the column AGE
        public static final int AGE_COLUMN = 6; 
    }
    ...
}

public String getType(Uri uri) {
    switch (uriMatcher.match(uri)) {
        case COLLECTION: return "vnd.android.cursor.dir/vnd.myCompany.contentType ";
        case ITEM: return "vnd.android.cursor.item/vnd.myCompany.contentType ";
        default: throw new IllegalArgumentException("URI non supportée : " + uri);
    }
}

// Crée les constantes utilisées pour différencier les requêtes URI
private static final int ITEM = 1;

private static final int COLLECTION = 2;

private static final UriMatcher uriMatcher;

// Alloue l'objet UriMatcher. 
// Une URI terminée par myPathToData correspondra à une requête sur une collection.
// Une URI terminée par'/[rowID]' correspondra à un item.
static {
    uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
    uriMatcher.addURI("MyAuthority", "myPathToData", COLLECTION);
    uriMatcher.addURI("MyAuthority ", " myPathToData /#", ITEM);
}

throw new UnsupportedOperationException();

<provider android:name=".FullyQualifiedNameOfTheContentProvider"
          android:authorities="TheAuthorityOfTheProvider" />

getContentResolver().registerContentObserver(URI, true, new MyContentObserver(handler));

getContext().getContentResolver().notifyChange(CONTENT_URI\pathToData\Item);

public class MyActivity extends Activity {
    ...
    // The URI of the ContentProvider
    URI ContentProviderURI=new URI(...);

    // The handler to manage modifications of data in a thread safe way
    Handler myHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            //update your data using the Handler Android pattern
            ...
        }
    };

    ...

    @Override
    public void onCreate(Bundle icicle) {
        ...
        getContentResolver().registerContentObserver(ContentProviderURI, true, 
        new myContentObserver(myHandler);
        ...
    }
    ...

    //The inner public class to observe the change on the data of the content Provider
    public class MyContentObserver extends ContentObserver {
        @Override
        public boolean deliverSelfNotifications() {
            return super.deliverSelfNotifications();
        }


        @Override
        public void onChange(boolean selfChange) {
            super.onChange(selfChange);
            //And then make a call to your handler
            handler.sendMessage(new Message());
        }
    }
    ...
}

public class MyActivity extends Activity {
    ...
    // The URI of the ContentProvider
    URI ContentProviderURI = new URI(...);

    // The handler to manage modifications of data in a thread safe way
    Handler myHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            // Update your data using the Handler Android pattern
            ...
        }
    };

    ...
    @Override
    public void onCreate(Bundle icicle) {
        ... // TheContent Observer
        ContentObserver myContentObserver = new ContentObserver (myHandler){
            @Override
            public void onChange(boolean selfChange) {
                super.onChange(selfChange);
                // And then make a call to your handler
                handler.sendMessage(new Message());
            };

            // Then register your Activity as a content observer

            getContentResolver().registerContentObserver(ContentProviderURI, true, myContentObserver);
            ...
        };
        ...
    }

/** 
* @author mSeguy
* @goals This class aims to make a exemple of a ContentProvider that uses SQLite
* <ul>
* <li></li>
* </ul>
*/
public class MyDataProvider extends ContentProvider {
    // *************************************************************************************
    // The Constants declaration ************************************************************
    // *************************************************************************************
    // Mon Authority, mes paths to data et mon URI

    // The Authority 
    public static final String AUTHORITY = "myAuthority";// package de la classe provider est préconisé (utilise des .)

    // The path to the data … and explain 
    public static final String PATH_TO_DATA = "myPath"; // Vous pouvez déclarer plusieurs paths (les paths utilisent les /)

    /** 
    * @author mSeguy
    * @goals This class aims to show the constant to use for the MyDataProvider
    */
    public static class Constants implements BaseColumns {
        // The URI and explain, with example if you want 
        public static final Uri CONTENT_URI = Uri.parse("content://" + MyDataProvider.AUTHORITY + "/" + MyDataProvider.PATH_TO_DATA);

        // Mon MIME type
        // My Column ID and the associated explanation 
        public static final String MIME_COLLECTION = "vnd.android.cursor.dir/vnd.myCompany.contentType";

        // My Column ID and the associated explanation 
        public static final String MIME_ITEM = "vnd.android.cursor.item/vnd.myCompany.contentType";

        // Noms de colonnes
        // /!\Si vous utilisez une base de données, les noms des colonnes sont les mêmes que ceux de
        // votre base, de même pour les index.
        // My Column ID and the associated explanation for end-users 
        public static final String KEY_COL_ID = "_id";// Mandatory

        // My Column Name and the associated explanation for end-users 
        public static final String KEY_COL_NAME = "name";

        // My Column First Name and the associated explanation for end-users 
        public static final String KEY_COL_FIRSTNAME = "firstName";

        // My Column Eyes Color and the associated explanation for end-users 
        public static final String KEY_COL_EYES_COLOR = "eyesColor";

        // My Column Hair color and the associated explanation for end-users 
        public static final String KEY_COL_HAIR_COLOR = "hairColor";

        // My Column age and the associated explanation for end-users 
        public static final String KEY_COL_AGE = "age";

        // Indexes des colonnes
        // The index of the column ID 
        public static final int ID_COLUMN = 1;

        // The index of the column NAME 
        public static final int NAME_COLUMN = 2;

        // The index of the column FIRST NAME 
        public static final int FIRSTNAME_COLUMN = 3;

        // The index of the column EYES COLOR 
        public static final int EYES_COLOR_COLUMN = 4;

        // The index of the column HAIR COLOR 
        public static final int HAIR_COLOR_COLUMN = 5;

        // The index of the column AGE 
        public static final int AGE_COLUMN = 6;
    }

    // Back To our provider
    @Override
    public boolean onCreate() {
        Context context = getContext();
        MyDatabaseHelper dbHelper = new MyDatabaseHelper(context, DATABASE_NAME, null,
        DATABASE_VERSION);
        myDB = dbHelper.getWritableDatabase();
        return (myDB == null) ? false : true;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sort) {

        SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
        qb.setTables(MY_TABLE);
        // S'il s'agit d'une requête sur une ligne, on limite le résultat.
        switch (uriMatcher.match(uri)) {
        case ITEM:
            qb.appendWhere(Constants.KEY_COL_ID + "=" + uri.getPathSegments().get(1));
            break;
        default:
            break;
        }

        // Si aucun ordre de tri n'est spécifié, tri par date/heure
        String orderBy;
        if (TextUtils.isEmpty(sort)) {
            orderBy = Constants.KEY_COL_NAME;
        } else {
            orderBy = sort;
        }

        // Applique la requête à la base.
        Cursor c = qb.query(myDB, projection, selection, selectionArgs, null, null, orderBy);

        // Enregistre le ContextResolver pour qu'il soit averti
        // si le résultat change.
        c.setNotificationUri(getContext().getContentResolver(), uri);

        // Renvoie un curseur.
        return c;
    }

    @Override
    public Uri insert(Uri _uri, ContentValues _initialValues) {
        // Insère la nouvelle ligne. Renvoie son numéro en cas de succès
        long rowID = myDB.insert(MY_TABLE, "data", _initialValues);

        // Renvoie l'URI de la nouvelle ligne.
        if (rowID > 0) {
            Uri uri = ContentUris.withAppendedId(Constants.CONTENT_URI, rowID);
            getContext().getContentResolver().notifyChange(uri, null);
            return uri;
        }
        throw new SQLException("Echec de l'ajout d'une ligne dans " + _uri);
    }

    @Override
    public int delete(Uri uri, String where, String[] whereArgs) {
        int count;

        switch (uriMatcher.match(uri)) {
        case COLLECTION:
            count = myDB.delete(MY_TABLE, where, whereArgs);
            break;

        case ITEM:
            String segment = uri.getPathSegments().get(1);
            count = myDB.delete(MY_TABLE, KEY_ID + "=" + segment
            + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs);
            break;

        default:
            throw new IllegalArgumentException("URI non supportée : " + uri);
        }

        getContext().getContentResolver().notifyChange(uri, null);
        return count;
    }

    @Override
    public int update(Uri uri, ContentValues values, String where, String[] whereArgs) {
        int count;
        switch (uriMatcher.match(uri)) {
        case COLLECTION:
            count = myDB.update(MY_TABLE, values, where, whereArgs);
            break;

        case ITEM:
            String segment = uri.getPathSegments().get(1);
            count = myDB.update(MY_TABLE, values, Constants.KEY_COL_ID + "=" + segment
            + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs);
            break;

        default:
            throw new IllegalArgumentException("URI inconnue " + uri);
        }

        getContext().getContentResolver().notifyChange(uri, null);
        return count;
    }

    @Override
    public String getType(Uri uri) {
        switch (uriMatcher.match(uri)) {
        case COLLECTION:
            return "vnd.android.cursor.dir/vnd.myCompany.contentType ";
        case ITEM:
            return "vnd.android.cursor.item/vnd.myCompany.contentType ";
        default:
            throw new IllegalArgumentException("URI non supportée : " + uri);
        }
    }

    // Crée les constantes utilisées pour différencier les requêtes URI
    private static final int ITEM = 1;
    private static final int COLLECTION = 2;

    private static final UriMatcher uriMatcher;

    // Alloue l'objet UriMatcher.
    // Une URI terminée par myPathToData correspondra à une requête sur une collection.
    // Une URI terminée par'/[rowID]' correspondra à un item.
    static {
        uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
        uriMatcher.addURI("MyAuthority", "myPathToData", COLLECTION);
        uriMatcher.addURI("MyAuthority ", " myPathToData /#", ITEM);
    }

    // Managing the database

    // La base de données
    private SQLiteDatabase myDB;

    private static final String TAG = "MyProvider";
    private static final String DATABASE_NAME = "myData.db";
    private static final int DATABASE_VERSION = 1;
    private static final String MY_TABLE = "MyTable";

    // Classe helper pour ouvrir, créer et gérer le contrôle de version de la base
    private static class MyDatabaseHelper extends SQLiteOpenHelper {
        private static final String DATABASE_CREATE = "create table " + MY_TABLE + " ("
            + Constants.KEY_COL_ID + " integer primary key autoincrement, "
            + Constants.KEY_COL_AGE + " INTEGER, " 
            + Constants.KEY_COL_NAME + " TEXT, "
            + Constants.KEY_COL_FIRSTNAME + " TEXT, " 
            + Constants.KEY_COL_EYES_COLOR+ " TEXT, " 
            + Constants.KEY_COL_HAIR_COLOR + " TEXT) ";

        public MyDatabaseHelper(Context context, String name, CursorFactory factory, int version) {
            super(context, name, factory, version);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL(DATABASE_CREATE);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            Log.w(TAG, "Mise à jour de la version " + oldVersion + " vers la version " + newVersion
                + ", les anciennes données seront détruites ");
            db.execSQL("DROP TABLE IF EXISTS " + MY_TABLE);
            onCreate(db);
        }
    }
}