Closing database connection with SqlBright

Question

I'm migrating the following pattern of accessing the Android app's SQLite database into the RxJava world:

public List<Stuff> doStuff(){
    synchronized (lock) {
        open(); // this effectively checks for isOpen() then calls getWritableDatabase()
        // query the database for stuff
        close(); // SQLiteOpenHelper close method
        return stuffList;
    }
}

Something I'm struggling is when should I close the database connection? I know there are patterns for not closing the connection at all as well as closing the connection as part of the Activity method. However, those patterns would require me applying the logic to the whole database manager class which I'd like to avoid if possible. Was hoping maybe there's a suggested way to handle this with RxJava and specifically SqlBright wrapper? My migrated code looks something like this:

public Observable<List<Stuff>> doStuff(){
    synchronized (lock) {
        open();
        String sql = <..>;
        return db.createQuery(tableName, sql, args).mapToList(mStuffMapper);
        // where do I close()?
    }
}

The solution I'm after, ideally, should allow me to change this one method, keeping the rest with the current open/close pattern.

Answer 1

You can use Subscription to close the connection.

db.createQuery(tableName, sql, args)
        .mapToList(mStuffMapper);
        .doOnSubscribe(new Action0() {
            @Override public void call() {
                close(); 
            }
        });

Subscription subscribe = doStuff().subscribe();
subscribe.unsubscribe();