TargetProvider.java

public class TargetProvider extends ContentProvider {
    final private String tag;
    final private String providerName;
    final private String dbName;
    final private String tableName;

    private SQLiteOpenHelper dbHelper = null;
    private UriMatcher uriMatcher = null;

    public TargetProvider(String providerName, String dbName, String tableName, String tag) {
        super();
        this.providerName = providerName;
        this.dbName = dbName;
        this.tableName = tableName;
        this.tag = tag;
    }

    @Override
    public boolean onCreate() {
        Log.d(tag, "PROVIDER CREATE");
        dbHelper = new TargetDBHelper(getContext(), dbName, TargetTable.Version, tag);
        uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
        uriMatcher.addURI(providerName, "main", 1);
        uriMatcher.addURI(providerName, "main/#", 2);
        return false;
    }

    @Override
    public Cursor query(@NonNull Uri uri, String[] columns,
                        String selection, String[] selectionArgs, String orderBy) {
        if (uriMatcher.match(uri) == 2) {
            long id;
            List<String> result = uri.getPathSegments();
            if (result != null) {
                id = Long.parseLong(result.get(1));
                selection = BaseColumns._ID + "=" + Long.toString(id) +
                        (selection == null ? "" : "AND (" + selection + ")");
            }
        }
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        if (db == null) {
            return null;
        } else {
            Cursor cursor = db.query(tableName, columns, selection, selectionArgs, null, null, orderBy);
            Log.v(tag, "query result=" + cursor.getCount());
            Context context = getContext();
            if (context != null) {
                cursor.setNotificationUri(context.getContentResolver(), uri);
            }
            return cursor;
        }
    }

    @Override
    public String getType(@NonNull Uri uri) {
        return null;
    }

    @Override
    public Uri insert(@NonNull Uri uri, ContentValues values) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        if (db == null) {
            return null;
        } else {
            long newId = db.insert(tableName, null, values);
            final Uri appendedUri = Uri.parse(uri + "/" + newId);
            Log.v(tag, "inserted id=" + newId);
            Context context = getContext();
            if (context != null) {
                context.getContentResolver().notifyChange(appendedUri, null);
            }
            return appendedUri;
        }
    }

    @Override
    public int delete(@NonNull Uri uri, String selection, String[] selectionArgs) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        if (db == null) {
            return 0;
        } else {
            final int count = db.delete(tableName, selection, selectionArgs);
            Log.v(tag, "deleted count=" + count);
            Context context = getContext();
            if (context != null) {
                context.getContentResolver().notifyChange(uri, null);
            }
            return count;
        }
    }

    @Override
    public int update(@NonNull Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        if (db == null) {
            return 0;
        } else {
            final int count = db.update(tableName, values, selection, selectionArgs);
            Log.v(tag, "updated count=" + count);
            Context context = getContext();
            if (context != null) {
                context.getContentResolver().notifyChange(uri, null);
            }
            return count;
        }
    }

    @Override
    public ParcelFileDescriptor openFile (@NonNull Uri uri, @NonNull String mode) throws FileNotFoundException {
        return openFileHelper(uri, mode);
    }
}