異常代碼：java.lang.NullPointerException     at com.atguigu.crud.test.MvcTest.testPage(MvcTest.java:53)     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)     at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)     at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)     at java.lang.reflect.Method.invoke(Unknown Source)     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.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:74)     at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:84)     at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)     at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)     at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)測(cè)試了一下:    MvcResult result = mockMvc.perform(MockMvcRequestBuilders.get("/emps").param("pn", "1")).andReturn();         MockHttpServletRequest request = result.getRequest();         System.out.println("1:"+request);         System.out.println("2:"+request.getAttribute("pageInfo"));結(jié)果:1:org.springframework.mock.web.MockHttpServletRequest@4a067c252:null是在執(zhí)行了getAttribute()這個(gè)方法后出現(xiàn)的異常代碼檢查了幾遍了，不知道是不是哪個(gè)配置文件出了問題。