问CompletableFuture和MockMVC

EN

public Future<List<AlertsBodyVO>> getAlerts(@PathVariable(value = "userId") final String userId) {
        return CompletableFuture.supplyAsync(() -> Service.getAlerts(userId));
    }


    @Test
    public void testGetAlerts_NullResult() throws Exception {
        String userId = "123456";

        List<AlertsBodyVO> alertsVOList = null;     

        Mockito.when(mockService.getAlerts(Mockito.anyString())).thenReturn(alertsVOList);

        MvcResult result = this.mockMvc.perform(get("/alerts/{userId}",  userId)).andExpect(status().isOk())
                .andReturn();

        mockMvc.perform(asyncDispatch(result)).andExpect(status().isOk())
                .andExpect(jsonPath("$").doesNotExist())
                .andReturn();        

        Mockito.verify(mockService, Mockito.times(1)).getAlerts(Mockito.anyString());
    }   

public Future<List<AlertsBodyVO>> getAlerts(@PathVariable(value = "userId") final String userId) {
        return CompletableFuture.supplyAsync(() -> Service.getAlerts(userId), executorService);
    }

java.lang.IllegalStateException: Async result for handler [public java.util.concurrent.Future<java.util.List<com.domain.AlertsBodyVO>> com.controllers.API.getAlerts(java.lang.String)] was not set during the specified timeToWait=10000
at org.springframework.test.web.servlet.DefaultMvcResult.getAsyncResult(DefaultMvcResult.java:146)
at org.springframework.test.web.servlet.DefaultMvcResult.getAsyncResult(DefaultMvcResult.java:136)
at org.springframework.test.web.servlet.request.MockMvcRequestBuilders.asyncDispatch(MockMvcRequestBuilders.java:269)
at com.controllers.APITest.testGetAlerts_NullResult(APITest.java:207)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:78)
at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:84)
at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:161)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)