android.database.CursorWindowAllocationException - 游标已关闭

Question

数据库游标抛出异常，表示游标已打开，每次都关闭。返回声明搞砸了吗？

public long getValue() {

        long val = 0;

        Cursor cursor = null;
        try {
            if (db != null) {
                cursor = db.query(*****);

                if (cursor.moveToFirst()) {
                    return cursor.getLong(cursor.getColumnIndex(****));
                }
            }
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
        return val;
    }

获得以下例外：

android.database.CursorWindowAllocationException: Cursor window allocation of 2048 kb failed. # Open Cursors=1 (# cursors opened by this proc=1)