Use one Fragment for one Tab in TabActivity

Currently I am trying to programm an android app. I would love to have there a Tab Activity where I can use one Fragment for one Tab. I have tried to follow this Tutorial, but Android Studio says:

Incopatible Types: 
        Required: android.support.v4.app.Fragment
        Found: de......fragment_nameOfTheFragment

Code of my Function in the Activity + import statements:

import android.support.design.widget.TabLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import de.noname.MYNAME.APPNAME.fragment_geocache_details;
import de.noname.MYNAME.APPNAME.fragment_geocache_details_waypoints;

@Override
public Fragment getItem(int position) {
    switch (position) {
        case 0:
            return new fragment_geocache_details_waypoints (); // Here is one fail
        case 1:
            return new fragment_geocache_details(); // Here is the other fail
    }
}

If more code is required then I will edit my Post. But I copied the code from the tutorial and just changed the names to my ones.

You do not use the correct import into the de......fragment_nameOfTheFragment

I think you have

import android.app.Fragment

and you need

import android.support.v4.app.Fragment;

EDIT

@Override
public Fragment getItem(int position) {
    Fragment f = null;
    switch (position) {
        case 0:
            f =  new fragment_geocache_details_waypoints (); // Here is one fail
            break; 
        case 1:
            f = new fragment_geocache_details(); // Here is the other fail
            break;
    }
    return f;
}

or

@Override
public Fragment getItem(int position) {
    switch (position) {
        case 0:
            return new fragment_geocache_details_waypoints (); // Here is one fail
        case 1:
            return new fragment_geocache_details(); // Here is the other fail
        default:
            //Do something by default like throw an exception
    }
}