Sample_of_SwapCursor.java

/**
 * Change the underlying cursor to a new cursor. If there is an existing
 * cursor it will be closed.
 */
public void setData(Cursor cursor) {
    Cursor old = swapCursor(cursor);
    if (old != null && !old.isClosed()) {
        old.close();
    }
}

/**
 * Swap in a new Cursor, returning the old Cursor. Unlike
 * {@link #setData(Cursor)}, the returned old Cursor is <em>not</em>
 * closed.
 */
private Cursor swapCursor(Cursor newCursor) {
    if (newCursor == mCursor) {
        return null;
    }
    final Cursor oldCursor = mCursor;
    if (oldCursor != null && mDataSetObserver != null) {
        oldCursor.unregisterDataSetObserver(mDataSetObserver);
        oldCursor.close();
    }
    mCursor = newCursor;
    if (mCursor != null) {
        if (mDataSetObserver != null) {
            mCursor.registerDataSetObserver(mDataSetObserver);
        }
        mRowIdColumn = newCursor.getColumnIndexOrThrow(BaseColumns._ID);
        mDataValid = true;
    } else {
        mRowIdColumn = -1;
        mDataValid = false;
        //There is no notifyDataSetInvalidated() method in RecyclerView.Adapter
    }
    notifyDataSetChanged();
    return oldCursor;
}