Android: using getIntent() only within onCreate?

Question

In Android (targeting APIs 14-16) I have a MainActivity and a NextActivity. There is no difficulty using intents to start NextActivity from within MainActivity if the getIntent() method is called inside the onCreate() block of NextActivity:

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        int data = 7;
        ...
        Intent intent = new Intent(this, NextActivity.class);
        intent.putExtra("data", data);
        startActivity(intent);
        }
    }

public class NextActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        final int data = this.getIntent().getIntExtra("data", 7);
        ...
        }
    ...
    }

However, since the field data is being used inside an anonymous ("inner") class in NextActivity, I am compelled to declare it final.

I'd prefer not to declare fields final, and I can usually avoid doing so if I declare them at the beginning of the class, before onCreate() begins. But for some reason, the app crashes when NextActivity starts if the getIntent() statement appears (without the final keyword) outside of onCreate().

Any idea why?

Answer 1

You can't getIntent() before onCreate() -- there's simply no Intent available at that point. I believe the same is true for anything that requires a Context.

Your anonymous inner class can still call getIntent(), however, so you don't need to declare this as a variable at all.