使用spring webflux时,WebTestClient不工作

我通过Spring boot 2.0.0.M3使用Spring webflux。下面是我项目的依赖项,

dependencies {
compile 'org.springframework.boot:spring-boot-starter-actuator',
        'org.springframework.cloud:spring-cloud-starter-config',
        'org.springframework.cloud:spring-cloud-sleuth-stream',
        'org.springframework.cloud:spring-cloud-starter-sleuth',
        'org.springframework.cloud:spring-cloud-starter-stream-rabbit',
        'org.springframework.boot:spring-boot-starter-data-mongodb-reactive',
        'org.springframework.boot:spring-boot-starter-data-redis-reactive',
        'org.springframework.boot:spring-boot-starter-integration',
        "org.springframework.integration:spring-integration-amqp",
        "org.springframework.integration:spring-integration-mongodb",
        'org.springframework.retry:spring-retry',
        'org.springframework.boot:spring-boot-starter-webflux',
        'org.springframework.boot:spring-boot-starter-reactor-netty',
        'com.fasterxml.jackson.datatype:jackson-datatype-joda',
        'joda-time:joda-time:2.9.9',
        'org.javamoney:moneta:1.0',
        'com.squareup.okhttp3:okhttp:3.8.1',
        'org.apache.commons:commons-lang3:3.5'
compileOnly 'org.projectlombok:lombok:1.16.18'
testCompile 'org.springframework.boot:spring-boot-starter-test',
        'io.projectreactor:reactor-test',
        'org.apache.qpid:qpid-broker:6.1.2',
        'de.flapdoodle.embed:de.flapdoodle.embed.mongo'
}

该应用程序通过运行良好 ./gradlew bootRun 或者直接运行主应用程序。

我想知道为什么 WebTestClient

下面是我的测试用例的代码片段,

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class NoteHandlerTest {

@Autowired
private WebTestClient webClient;

@Test
public void testNoteNotFound() throws Exception {
    this.webClient.get().uri("/note/request/{id}", "nosuchid").accept(MediaType.APPLICATION_JSON_UTF8)
            .exchange().expectStatus().isNotFound();
}
}