Spring Security Test因NullPointerException而失败

Question

使用Spring Security 3.2.5和Spring Secuirty Test 4.0.0.M1工件，我无法成功运行以下单元测试：

  @Test
    public void testRequestOAuthToken() throws Exception {
        this.mockMvc.perform(post("/oauth/token/")
                            .param("grant_type", "password")
                            .param("client_id", "ios")
                            .param("username", "user")
                            .param("password", "123c86b3634342f")
                            .contentType(MediaType.APPLICATION_FORM_URLENCODED)
                            .accept(MediaType.APPLICATION_JSON)

                            .with(user("ios").password("aabb03880fsddc665ffb9a0").roles("APP")))

                .andDo(print())
                .andExpect(status().isOk());
}

导致抛出 NullPointerException ：

java.lang.NullPointerException
    at org.springframework.security.test.web.support.WebTestUtils.findFilter(WebTestUtils.java:115)
    at org.springframework.security.test.web.support.WebTestUtils.getSecurityContextRepository(WebTestUtils.java:57)
    at org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors$SecurityContextRequestPostProcessorSupport.save(SecurityMockMvcRequestPostProcessors.java:436)
    at org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors$SecurityContextRequestPostProcessorSupport.save(SecurityMockMvcRequestPostProcessors.java:424)
    at org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors$AuthenticationRequestPostProcessor.postProcessRequest(SecurityMockMvcRequestPostProcessors.java:560)
    at org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors$UserDetailsRequestPostProcessor.postProcessRequest(SecurityMockMvcRequestPostProcessors.java:585)
    at org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors$UserRequestPostProcessor.postProcessRequest(SecurityMockMvcRequestPostProcessors.java:699)
    at org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder.postProcessRequest(MockHttpServletRequestBuilder.java:686)
    at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:137)
    at com.mycomp.OAuthUnitTests.testRequestOAuthToken(OAuthUnitTests.java:88)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:73)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:82)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:73)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:217)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:83)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:68)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:163)
    at org.junit.runners.Suite.runChild(Suite.java:127)
    at org.junit.runners.Suite.runChild(Suite.java:26)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)

任何提示？这是我的Spring Unit Test配置：

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@ContextConfiguration( locations = { "file:src/main/webapp/WEB-INF/applicationContext.xml", "file:src/main/webapp/WEB-INF/securityApplicationContext.xml" })
public class OAuthUnitTests {

    @Autowired
    private WebApplicationContext wac;

    @Autowired
    private Filter springSecurityFilterChain;

    private MockMvc mockMvc;

    @Before
    public void setUp() {
        this.mockMvc = webAppContextSetup(this.wac)
                .addFilters(springSecurityFilterChain)
                .build();
    }