您的ExcludePopulationProperties类不应使用@Component进行注解。相反，您应该在项目中的配置类上使用@EnableConfigurationProperties(ExcludePopulationProperties.class)注解（主应用程序类将正常工作）。
将属性类更改为如下所示（删除@Component）：

@Data
@ConfigurationProperties(prefix = "project")
public class ExcludePopulationProperties {
   ...
}

更改应用程序类以启用配置属性：

@SpringBootApplication
@EnableConfigurationProperties(ExcludePopulationProperties.class)
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

YamlTest类如下所示（使用@SpringBootTest）：

@SpringBootTest
@ContextConfiguration(classes = { DemoApplication.class })
@TestPropertySource(properties = { "spring.config.location=classpath:application-test.yaml" })
class YamlTest {

    @Autowired
    private ExcludePopulationProperties excludePopulationProperties;

    @Test
    void testExternalConfiguration() {
        Map<String, String> map = excludePopulationProperties.getTest().getService().getComputator().getPopulation().getExclude();
        assertNotNull(map);
        assertEquals(map.get("InputClass"), "myDate");
        assertEquals(map.get("AnotherClass"), "myName");
    }
}

有了这些小的变化，现在我能够测试的属性从YAML文件。
我稍微改进了一下yaml：

# test placeholders

project:
  test:
    service:
      computator:
        # exclude field from beeing randomly valorized
        population:
          exclude:
            InputClass: 
               - 'myDate'
            AnotherClass: 
               - 'myName'

所以现在ExcludePopulationProperties有一个Map〈String，List〉而不是Map〈String，String〉，这样我就可以从同一个类中排除多个字段：

@Data
@Configuration
@ConfigurationProperties(prefix = "project")
@PropertySource(value = "classpath:application-_test.yaml", factory = YamlPropertySourceFactory.class)
public class ExcludePopulationProperties {

    private Test test;

    @Data
    public static class Test {
        private Service service;
    }

    @Data
    public static class Service {
        private Computator computator;
    }

    @Data
    public static class Computator {
        private Population population;
    }

    @Data
    public static class Population {
        private Map<String, List<String>> exclude;
    }

}

YamlPropertySourceFactory是Baeldung在本指南中实现的类：在Sping Boot 中使用YAML文件的@PropertySource

public class YamlPropertySourceFactory implements PropertySourceFactory {

    @Override
    public PropertySource<?> createPropertySource(String name, EncodedResource resource) throws IOException {
        YamlPropertiesFactoryBean factory = new YamlPropertiesFactoryBean();
        factory.setResources(resource.getResource());

        Properties properties = factory.getObject();

        return new PropertiesPropertySource(resource.getResource().getFilename(), properties);
    }

}

测试类别：

@EnableConfigurationProperties
@ContextConfiguration(classes = { ExcludePopulationProperties.class })
@TestPropertySource(properties = { "spring.config.location=classpath:application-_test.yaml" })
@ExtendWith(SpringExtension.class)
class YamlTest {

    @Autowired
    private ExcludePopulationProperties excludePopulationProperties;

    @Test
    void testExternalConfiguration() {
        Map<String, List<String>> map = excludePopulationProperties.getTest().getService().getComputator().getPopulation().getExclude();
        assertNotNull(map);
    }

}

请注意，对于Mockito，您需要同时使用SpringExtension和MockitoExtension：

@EnableConfigurationProperties
@ContextConfiguration(classes = { ExcludePopulationProperties.class })
@Extensions({
        @ExtendWith(SpringExtension.class),
        @ExtendWith(MockitoExtension.class)
})
class YamlTest {

}

更新

我找到了一个更好的解决方案，以避免在所有测试类上都写注解。
添加Jacksonjackson-dataformat-yaml依赖项

<dependency>
  <groupId>com.fasterxml.jackson.dataformat</groupId>
  <artifactId>jackson-dataformat-yaml</artifactId>
  <version>${jackson-dataformat-yaml.version}</version>
</dependency>

配置属性类将为：

@Data
public class ExcludePopulationProperties {

    private Project project;

    @Data
    public static class Project {
        private Test test;
    }

    @Data
    public static class Test {
        private Service service;
    }

    @Data
    public static class Service {
        private Computator computator;
    }

    @Data
    public static class Computator {
        private Population population;
    }

    @Data
    public static class Population {
        private Map<String, List<String>> exclude;
    }

    public static ExcludePopulationProperties build() throws IOException {
        InputStream inputStream = new FileInputStream(new File("./src/test/resources/" + "application-_test.yaml"));
        YAMLMapper mapper = new YAMLMapper();
        mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
        mapper.enable(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY);
        return mapper.readValue(inputStream, ExcludePopulationProperties.class);
    }

}

然后，在任何需要的地方，只需调用静态构建方法，测试类将更加简单：

@ExtendWith(SpringExtension.class)
class YamlTest {

    @Test
    void testExternalConfiguration() throws IOException {
        Map<String, List<String>> map = ExcludePopulationProperties.build().getProject().getTest().getService().getComputator().getPopulation().getExclude();
        assertNotNull(map);
    }

}