Springmvc上传文件request转换异常

异常提示

严重: Servlet.service() for servlet [springmvc] in context with path [/pms] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: org.apache.catalina.connector.RequestFacade cannot be cast to org.springframework.web.multipart.MultipartHttpServletRequest] with root causejava.lang.ClassCastException: org.apache.catalina.connector.RequestFacade cannot be cast to org.springframework.web.multipart.MultipartHttpServletRequest    at com.XXX.web.useSet.controller.ContractController.contractImport(ContractController.java:225)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:606)    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:838)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)    at org.springframework.orm.hibernate4.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:152)    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:315)    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)    at java.lang.Thread.run(Thread.java:745)

相信大家都会遇到这样的异常情况，我今天百度了半天没找到，最后找到了原因。

首先是Springmvc配置文件的问题：

<!-- 文件上传下载支持 -->     <bean id="multipartResolver"          class="org.springframework.web.multipart.commons.CommonsMultipartResolver">    <!-- 文件上传的最大值,配置为最大10M -->        <property name="maxUploadSize" value="10240000"/>        <property name="maxInMemorySize" value="4096"/>        <property name="defaultEncoding" value="UTF-8"/>    </bean>    ```##这个配置文件如果添加之后还出现这样的问题的话，请先清理一下缓存。如果还不行，请看下面的。

导入合同归档

---

    1、<button style="width:111px;height:32px; line-height:32px; text-align:center; color:#fff; border:none; border-radius:5px;background-color:#1ab394"><a href="${pageContext.request.contextPath}/contract/downloadContracTemplate.do" style="color:#fff;">下载Excel格式</a></button><br><br>    2、按照Excel格式，整理合同信息，不要调整列的顺序。<br/><br>    3、选择要导入的文件。    <form action="" method="post" id="contractForm" role="form" >    <div class="file_div">    <div class="files_cont">       <div class="btn">        <span>选择文件</span>        <input type="file" id="contractFile" name="myContractFile" >       </div>       <div class="we_flie">         <p>未选择任何文件</p>       </div>    </div>

“`

我在提交form表单的时候才发现，表单并没有写enctype=”multipart/form-data”.

百度之后才知道 enctype=”multipart/form-data”.是是设置表单的MIME编码。默认情况，这个编码格式是application/x-www-form-urlencoded，不能用于文件上传；只有使用了multipart/form-data，才能完整的传递文件数据，进行下面的操作.

enctype=”multipart/form-data”是上传二进制数据; form里面的input的值以2进制的方式传过去。

所以，才会出现那种问题。添加上之后解决了~~~

欢迎大家留言，一起交流，共同进步！
By：Tiger丶D