Fragment activity reference after screen rotation

I have an Activity with two Action bar tabs with one fragment in each tab. Everything is working properly until a screen rotation. I have references to the fragments in my activity. If i call a method of the fragmet from my activity and that method call getActivity(), the getActivity() return null.

I don't know if i shouldn't have references to the fragments as member fields of my Activity class. If i can't keep that reference in the activity class, how can i get the values of some fields in the layout of a fragment.

Here is my activity class:

public class MyActivity extends ActionBarActivity implements ActionBar.TabListener {

    private ViewPager viewPager;
    private MyPagerAdapter pagerAdapter;
    private ActionBar actionBar;
    DetallesAvisoFragment fragment1;
    DetallesPiezaFragment fragment2;
    ActionMode actionMode;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_edit_avisos);

        actionBar = getSupportActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);


        viewPager = (ViewPager) findViewById(R.id.viewPager);
        Intent intent = getIntent();
        fragment1 = new Fragment1();
        fragment2 = new Fragment2();
        List<Fragment> fragmentList = new ArrayList<Fragment>();
        fragmentList.add(fragment1);
        fragmentList.add(fragment2);
        pagerAdapter = new MyPagerAdapter(getSupportFragmentManager(), fragmentList);
        viewPager.setAdapter(pagerAdapter);
        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int i, float v, int i2) {

            }

            @Override
            public void onPageSelected(int i) {
                actionBar.setSelectedNavigationItem(i);
            }

            @Override
            public void onPageScrollStateChanged(int i) {

            }
        });
        actionBar.addTab(actionBar.newTab().setText("Frag1 Tab").setTabListener(this));
        actionBar.addTab(actionBar.newTab().setText("Frag2 Tab").setTabListener(this));
    }




    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
        viewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {

    }

    @Override
    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {

    }

    /**
     * This method work properly until screen rotation
     */
    public void getValues() {
        String value1 = fragment1.getValueFromSomeField();
        String value2 = fragment2.getValueFromOtherField();
    }
}

The FragmentPagerAdapter class:

public class MyPagerAdapter extends FragmentPagerAdapter{

    List<Fragment> fragmentList;

    public MyPagerAdapter(FragmentManager fm, List<Fragment> fragments) {
        super(fm);
        fragmentList = fragments;
    }

    @Override
    public Fragment getItem(int index) {
        if (index >= fragmentList.size()) {
            return null;
        }
        return fragmentList.get(index);
    }

    @Override
    public int getCount() {
        return fragmentList.size();
    }
}

And my Fragment classes:

public class Fragment1 extends Fragment {

    public Fragment1() {
    }



    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceBundle) {
        return inflater.inflate(R.layout.fragment1_layout, container, false);;
    }


    public String getValueFromSomeField() {
        TextView testView = (TextView) getActivity().findViewById(R.id.someField);
        return testView.getText().toString();
    }
}


public class Fragment2 extends Fragment {

    public Fragment2() {
    }



    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceBundle) {
        return inflater.inflate(R.layout.fragment2_layout, container, false);;
    }


    public String getValueFromSomeOtherField() {
        TextView testView = (TextView) getActivity().findViewById(R.id.someOtherField);
        return testView.getText().toString();
    }
}

Note: I need support for SDK 8 so I have to use Fragments using the SupportLibrary