org.springframework.web.util.NestedServletException: Request processing failed; nested exception is

上传文件，点击保存时直接抛出了异常。


前提：服务之前是好的，后来更新了一个版本后出现异常了。修改的文件仅是增加日志。


网上说的web.xml的配置均有，如果是form表单提交 enctype="multipart/form-data"这个属性也有配置。nginx并未做限制上传文件大小。


异常日志如下：


## # 2018-01-03 17:41:43 [ERROR] [http-nio-8080-exec-20] com.cmcc.vrp.province.webin.controller.ErrorController.handle500Error(ErrorController.java:66) 
## # org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.web.multipart.MultipartException: Could not parse multipart servlet request; nested exception is org.apache.commons.fileupload.FileUploadBase$IOFileUploadException: Processing of multipart/form-data request failed. /opt/tomcat/work/Catalina/localhost/flowcard/upload_6e01cb10_160bb61b705__7ffd_00000000.tmp (Permission denied)
## # 2018-01-03 17:41:46 [ERROR] [http-nio-8080-exec-21] com.cmcc.vrp.province.webin.controller.ErrorController.handle500Error(ErrorController.java:66) 
## # org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.web.multipart.MultipartException: Could not parse multipart servlet request; nested exception is org.apache.commons.fileupload.FileUploadBase$IOFileUploadException: Processing of multipart/form-data request failed. /opt/tomcat/work/Catalina/localhost/flowcard/upload_6e01cb10_160bb61b705__7ffd_00000002.tmp (Permission denied)_

最后：解决的手段是重装了tomcat，就可以了。。。。。。

但是很想知道为嘛？T——T  先留个爪子印做个记录

补充原因：

/opt/tomcat/work/Catalina/localhost/flowcard/upload_6e01cb10_160bb61b705__7ffd_00000000.tmp (Permission denied)

因为这个目录的权限不对，上传时先要有缓存，这个就是缓存的临时目录。造成这个的原因的就是启动服务的权限不对，导致服务无法正常访问这个路径。