问题
@ResponseBody
@RequestMapping(value="addMultiDisCar",method=RequestMethod.POST)
public Map<String, Object> addMultiDisCar(HttpServletRequest request,File uploadFile){
User user=(User) request.getSession().getAttribute("loginUser");
Boolean isAdmin = authorityUtils.checkFunctionURL("distriCarMng.admin", user.getRoleList());
Boolean hasApprove = authorityUtils.checkFunctionURL("distriCarMng.audit", user.getRoleList());
Boolean hasDistri = authorityUtils.checkFunctionURL("distriCarMng.addDistriCar", user.getRoleList());
Boolean hasView = authorityUtils.checkFunctionURL("distriCarMng.search", user.getRoleList());
String state="4";
if(user != null ){
if(hasApprove){
state="1";
}
}
String auth = null;
if(isAdmin||hasApprove){//布控超级管理员或者有审批权限
auth = "ADV";
}else if(hasDistri){//布控查看权限
auth = "DV";
}else if(hasView){//查看权限
auth = "V";
}
Map<String, Object> map=distriCarMngRpc.addMultiDisCar(uploadFile, auth,user,state,request);
return map;
}
I have finished a function that needs me upload a excel file .And I used DHC tool to test.But it showed me a exception,like this:
org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [java.io.File]: No default constructor found; nested exception is java.lang.NoSuchMethodException: java.io.File.<init>()
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:108)
at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:138)
at org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.createAttribute(ServletModelAttributeMethodProcessor.java:81)
at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:104)
at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:79)
at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:157)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:124)
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:748)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:833)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
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 com.botech.skynet.index.controller.LoginFilter.doFilter(LoginFilter.java:99)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.jasig.cas.client.util.AssertionThreadLocalFilter.doFilter(AssertionThreadLocalFilter.java:50)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.jasig.cas.client.util.HttpServletRequestWrapperFilter.doFilter(HttpServletRequestWrapperFilter.java:70)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.jasig.cas.client.validation.AbstractTicketValidationFilter.doFilter(AbstractTicketValidationFilter.java:238)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.jasig.cas.client.authentication.AuthenticationFilter.doFilter(AuthenticationFilter.java:152)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.jasig.cas.client.session.SingleSignOutFilter.doFilter(SingleSignOutFilter.java:100)
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:108)
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.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoSuchMethodException: java.io.File.<init>()
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.getDeclaredConstructor(Unknown Source)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:105)
... 59 common frames omitted
So I added a breakpoint on first line of this function body:User user=(User) request.getSession().getAttribute("loginUser"); But it seemed never come to my breakpoint. Can somebody help me ? Any answer will be appreciated.
回答1:
For uploading file you do not need to use File in your functions arguments, because the 'HttpServletRequest' has the file itself! You can change your code like this:
@RequestMapping(value="addMultiDisCar",method=RequestMethod.POST)
public @ResponseBody Map<String, Object> addMultiDisCar(HttpServletRequest request){
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
List<MultipartFile> files = multipartRequest.getFiles("files");
//...
//Now you have a List of Multipartfile that you can simply change to File...
}
回答2:
Follow FileUploadController from Spring docs
Your issue is caused as Spring MVC is trying to instantiate File object as a form bean with default constructor.
来源：https://stackoverflow.com/questions/34715338/springmvc-upload-file-exception