我有一个SpringBoot 2和Junit 5的应用程序，现在我试着做一个测试，我有一个叫做OrderService的类，看起来像这样：

@Component
public class OrderService {
@Value("#{'${food.requires.box}'.split(',')}")
private List<String> foodRequiresBox;

@Value("#{'${properties.prioritization}'.split(',')}")
private List<String> prioritizationProperties;

@Value("${further.distance}")
private Integer slotMeterRange;

@Value("${slot.meters.long}")
private Double slotMetersLong;

如您所见，该类有许多@Value注解，这些注解从www.example.com文件中提取值application.properties。
在POM文件中，我有以下依赖关系：

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
    </parent>
    <dependencies>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>5.1.0</version>
    </dependency>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-api</artifactId>
        <version>RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.junit.platform</groupId>
        <artifactId>junit-platform-launcher</artifactId>
        <version>1.1.0</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
        <version>2.0.5.RELEASE</version>
    </dependency>

在test/resources文件夹中，我有application.properties包含以下信息的www.example.com文件：

properties.prioritization:vip,food
food.requires.box:pizza,cake,flamingo
further.distance:2
slot.meters.long:0.5

测试文件如下所示：

@ExtendWith(SpringExtension.class)
@TestPropertySource(locations="classpath:application.properties")
public class OrderServiceTest {

    OrderService orderService;

    @BeforeEach
    void before(){
        orderService = new OrderService();
    }

    @Test
    void findAll() {
        Order order = new Order().withDescription("2x Pizza with Salad\\n2x Kebab with Fries\\n1x Hot dog with Fries\\n2x Pizza with Fries");
        assertTrue(orderService.orderHasFood.test(order));
    }
}

但是当测试尝试使用foodRequiresBox时抛出了NullPointerException，因此读取www.example.com文件时出现了问题application.properties。
你能告诉我如何读取application.properties文件进行测试吗？