Lost with imports and differences in Android Studio

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        mViewPager
                .setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
                    @Override
                public void onPageSelected(int position) {
                        actionBar.setSelectedNavigationItem(position);
                    }
                });

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a
 * {@link FragmentPagerAdapter} derivative, which will keep every
 * loaded fragment in memory. If this becomes too memory intensive, it
 * may be best to switch to a
 * {@link android.support.v13.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;
public static  final String TAG = MainActivity.class.getSimpleName();

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

    ParseAnalytics.trackAppOpened(getIntent());

    ParseUser currentUser = ParseUser.getCurrentUser();
    if (currentUser == null) {

        navigateToLogin();

    }
    else {
        Log.i(TAG, currentUser.getUsername());
    }
        final ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // Create the adapter that will return a fragment for each of the three
        // primary sections of the activity.
        mSectionsPagerAdapter = new SectionsPagerAdapter(this,
                getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        mViewPager
                .setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
                    @Override
                public void onPageSelected(int position) {
                        actionBar.setSelectedNavigationItem(position);
                    }
                });

    for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
        actionBar.addTab(actionBar.newTab()
        .setText(mSectionsPagerAdapter.getPageTitle(i))
        .setTabListener(this));
    }


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

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

}

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

}

private void navigateToLogin() {
    Intent intent = new Intent(this, LoginActivity.class);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); //Puts this in the front of the stack
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK); // clears previous activity
    startActivity(intent);
}


@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;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int itemId = item.getItemId();
    if (itemId == R.id.action_logout) {
        ParseUser.logOut();
        navigateToLogin();
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class DummySectionFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";



    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main,
                container, false);
        TextView dummyTextView = (TextView) rootView
                .findViewById(R.id.section_label);
        dummyTextView.setText(Integer.toString(getArguments().getInt(
                ARG_SECTION_NUMBER)));
        return rootView;
    }
}

    protected Context mContext;

    public SectionsPagerAdapter(Context context, FragmentManager fm) {


        super(fm);
        mContext = context;
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class below).
        Fragment fragment = new DummySectionFragment();
        Bundle args = new Bundle();
        args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
        fragment.setArguments(args));
        return fragment;
    }

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

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
            case 0:
                return mContext.getString(R.string.title_section1).toUpperCase(l);
            case 1:
                return mContext.getString(R.string.title_section2).toUpperCase(l);
        }
        return null;
    }
}