How to run simple junit for restful webservices in java?

I try to run unit tests for 2 methods. When I run JUnit test for testRetrieveAllHotels_ServiceLayer() method it works sucessfully, but when I try to run JUnit test for testRetrieveAllHotels_WebLayer() method, I get this error: java.lang.NullPointerException

This is the code:

package com.xxx.restfultesting.controller;

import static org.hamcrest.CoreMatchers.containsString;
import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

import java.util.Arrays;

import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.test.web.servlet.RequestBuilder;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;

import com.xxx.restfultesting.business.HotelBusinessService;
import com.xxx.restfultesting.model.Hotel;

@RunWith(SpringRunner.class)             
@WebMvcTest(HotelController.class)  
public class HotelControllerTest {

    @Autowired
    private MockMvc mockMvc;    

    @MockBean
    private HotelBusinessService businessService;

    @Test
    public void testRetrieveAllHotels_ServiceLayer(){

        businessService.retrieveAllHotels();

        verify(businessService, times(1)).retrieveAllHotels();
    }

    @Test
    public void testRetrieveAllHotels_WebLayer(){

        HotelController hotelController = new HotelController();

        when(businessService.retrieveAllHotels()).thenReturn(               
                Arrays.asList(new Hotel(1, "Sofitel", 120, 20),
                        new Hotel(2, "Ibis", 50, 40),
                        new Item(3, "Marriot", 200, 15)));

        hotelController.retrieveAllHotels();

        verify(businessService, times(1)).retrieveAllHotels();
    }

HotelController:

package com.xxx.restfultesting.controller;

import java.net.URI;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
import org.springframework.web.util.UriComponents;
import org.springframework.web.util.UriComponentsBuilder;

import com.xxx.restfultesting.business.HotelBusinessService;
import com.xxx.restfultesting.model.Hotel;

@RestController
public class HotelController {

    @Autowired
    private HotelBusinessService businessService;

    @GetMapping("/items")
    public List<Hotel> retrieveAllHotels() {

        System.out.println("Debugging 1"); 

        List<Hotel> hotels = businessService.retrieveAllHotels();

        return items; 
    }

HotelBusinessService:

package com.xxx.restfultesting.business;

import java.util.List;
import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.xxx.restfultesting.data.HotelRepository;
import com.xxx.restfultesting.model.Hotel;

@Component
public class HotelBusinessService {

    @Autowired
    private HotelRepository repository;

    public List<Hotel> retrieveAllHotels() {

        System.out.println("Debugging 2");

        List<Hotel> hotels = repository.findAll(); 

        return hotels;  
    }
}

I put System.out.println("Debugging 1") inside retrieveAllHotels() method from Controller and System.out.println("Debugging 2") inside retrieveAllHotels() method from Service. These are only for debugging. When I run JUnit test for testRetrieveAllHotels_ServiceLayer() method, it works successfully, but I don't get "Debugging 2" in the console.

When I run JUnit test for testRetrieveAllHotels_WebLayer() method I get the java.lang.NullPointerException error and I get "Debugging 1" in the console. I try to understand why there is not "Debugging 2" in the first case and how to run successfully the second method. Any feedback will be apreciated!