今天写用spring的MockMvc测试controller的demo时出现了这个错误，条件反射的进行了百度,没有搜到匹配的答案，但给了一些解决问题的思路；首先NoSuchMethodError要不就是没有方法,要不就是jar包冲突了,由于编译没报错又是用的spring使我觉得大概率是jar包冲突导致的，于是检查了我的pom文件,发现我spring-test的依赖版本是4.3.13而spring-web的版本是4.1.2，于是将test的版本改成4.1.2,问题解决了；下面贴下我的代码和报错代码：
我测试demo的代码：
错误代码：
java.lang.NoSuchMethodError: org.springframework.util.StreamUtils.emptyInput()Ljava/io/InputStream;
at org.springframework.mock.web.MockHttpServletRequest.<clinit>(MockHttpServletRequest.java:98)
at org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder.createServletRequest(MockHttpServletRequestBuilder.java:675)
at org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder.buildRequest(MockHttpServletRequestBuilder.java:586)
at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:141)
at com.darling.test.TestDemo.testTestController(TestDemo.java:24)
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.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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)