API 21 setSelectedNavigationItem and addTab are deprecated?

Question

I'm relatively new to android programming and I've encountered problem to do with API 21. This code below was working perfectly. But when I updated to API 21, setSelectedNavigationItem and addTab are deprecated. I've read a fair amount about the problem and seen a good few examples, but I still can get my head around it. Any Help would be very much appreciated. Thanks

JAVA CODE:

public class MainActivity extends FragmentActivity implements ActionBar.TabListener {

ActionBar actionBar;
ViewPager viewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    viewPager = (ViewPager) findViewById(R.id.pager);
    viewPager.setAdapter(new MyAdapter(getSupportFragmentManager()));
    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        }

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

        @Override
        public void onPageScrollStateChanged(int state) {
        }
    });
    actionBar = getActionBar();
    assert actionBar != null;
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    ActionBar.Tab tab1 = actionBar.newTab();
    tab1.setText("TAB1");
    tab1.setTabListener(this);

    ActionBar.Tab tab2 = actionBar.newTab();
    tab2.setText("TAB2");
    tab2.setTabListener(this);

    actionBar.addTab(tab1);
    actionBar.addTab(tab2);
}

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

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

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

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
    super(fm);
}

@Override
public Fragment getItem(int position) {
    Fragment fragment = null;
    if (position == 0) {
        fragment = new FragmentA();
    }
    if (position == 1) {
        fragment = new FragmentB();
    }
    return fragment;
}

@Override
public int getCount() {
    return 2;
}

One of my Fragments:

public class FragmentB extends Fragment {

public FragmentB() {
    // Required empty public constructor
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_b, container, false);
}

}