Question

I’m trying to pass my dbhelper instance from one activity to another using this code

    private void onCategoriesClick() {
        private DbAdapter db;
        db = new DbAdapter(this); 
        Intent i = new Intent(this, CategoriesActivity.class);
        Bundle b = i.getExtras();
        b.putSerializable("db", db); //geting NullPointerException here
        startActivityForResult(i, 0);    

DbAdapter class implements Serializable

I’m geting confused, could anybody point my mistake?

Answer 1

getExtras() returns null, because you haven’t put any extras into the Intent before you call it. This means that b == null, hence the NPE. Just put the serializable in the intent directly.

i.putExtra("db", (Serializable) db);

In general, though, avoid passing serializables over intents if you can help it.