MultipartFile upload yields 500 when no file

[hathawa]

I have a MVC controller uploads multiple files. It works fine if I specify at least one file,
but fails if no files are specified. The server is Tomcat 7 and returns a 500 (internal server error)
status code. The controller method (which never gets called) is:

	public @ResponseBody ExecuteQueryResult executeQuery( @RequestParam("ksUrl") String ksUrl,
			@RequestParam("serviceName") String serviceName,
			@RequestParam(value="file",required=false) MultipartFile[] file,
			@RequestParam("query") String query,
			HttpServletResponse response) {

According to Firebug the request looks like:

Headers

Connection	close
Content-Length	1000
Content-Type	text/html;charset=utf-8
Date	Fri, 20 Jul 2012 00:06:26 GMT
Server	Apache-Coyote/1.1
Request Headers
Accept	application/json, text/javascript, */*; q=0.01
Accept-Encoding	gzip, deflate
Accept-Language	en-us,en;q=0.5
Connection	keep-alive
Content-Length	888
Content-Type	multipart/form-data; boundary=---------------------------23805158906729
Host	localhost:8080
Referer	http://localhost:8080/queryserver-1.0.1/
User-Agent	Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20100101 Firefox/13.0.1
X-Requested-With	XMLHttpRequest

Source

-----------------------------23805158906729 Content-Disposition: form-data; name="ksUrlId" 5 -----------------------------23805158906729 Content-Disposition: form-data; name="ksUrl" http://localhost:8080/sadlserver-cxf-service-1.0.3/SadlService -----------------------------23805158906729 Content-Disposition: form-data; name="serviceName" InScope-CFM56-7 -----------------------------23805158906729 Content-Disposition: form-data; name="file" -----------------------------23805158906729 Content-Disposition: form-data; name="savedQueryId" 3 -----------------------------23805158906729 Content-Disposition: form-data; name="query" select ?cw where {<Transfer_Gearbox_Module-111111> <candidate_Workscope> ?cw } -----------------------------23805158906729 Content-Disposition: form-data; name="queryName" -----------------------------23805158906729--

Any ideas?
Thanks in advance.

Barry

[Marten Deinum]

Post the stacktrace from the logging (using [ code][/code ] tags) that should hold the key to your solution.

[hathawa]

Post the stacktrace from the logging (using [ code][/code ] tags) that should hold the key to your solution.

There was no stacktrace since the request never got to my code.

[Marten Deinum]

There must be something an 500 indicates in general that there is a stacktrace somewhere. The fact that it doesn't reach your controller doesn't matter, I suspect the error comes from the MultipartResolver however I want to be sure. So enable some more logging to see what is happening, simply the code and the requests that are send aren't giving any information...

[hathawa]

After turning on full debugging in Spring I got the following messages:

2012-07-20 10:19:54,475 DEBUG [org.springframework.web.servlet.DispatcherServlet] [http-bio-8080-exec-10] DispatcherServlet with name 'appServlet' processing POST request for [/queryserver-1.0.1/execute-query]
2012-07-20 10:19:54,506 DEBUG [org.springframework.web.servlet.handler.AbstractHandlerMethodMapping] [http-bio-8080-exec-10] Looking up handler method for path /execute-query
2012-07-20 10:19:54,506 DEBUG [org.springframework.web.servlet.handler.AbstractHandlerMethodMapping] [http-bio-8080-exec-10] Returning handler method [public com.ge.research.sadl.queryserver.webapp.controller.ExecuteQueryResult com.ge.research.sadl.queryserver.webapp.controller.QueryController.executeQuery(java.lang.String,java.lang.String,org.springframework.web.multipart.MultipartFile[],java.lang.String,javax.servlet.http.HttpServletResponse)]
2012-07-20 10:19:54,506 DEBUG [org.springframework.beans.factory.support.AbstractBeanFactory] [http-bio-8080-exec-10] Returning cached instance of singleton bean 'queryController'
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initializing new StandardEnvironment
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemProperties] PropertySource with lowest search precedence
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemEnvironment] PropertySource with lowest search precedence
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initializing new StandardEnvironment
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemProperties] PropertySource with lowest search precedence
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemEnvironment] PropertySource with lowest search precedence
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initializing new StandardEnvironment
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemProperties] PropertySource with lowest search precedence
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemEnvironment] PropertySource with lowest search precedence
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initializing new StandardEnvironment
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemProperties] PropertySource with lowest search precedence
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemEnvironment] PropertySource with lowest search precedence
2012-07-20 10:19:54,506 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
2012-07-20 10:19:54,522 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initializing new StandardEnvironment
2012-07-20 10:19:54,522 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemProperties] PropertySource with lowest search precedence
2012-07-20 10:19:54,522 DEBUG [org.springframework.core.env.MutablePropertySources] [http-bio-8080-exec-10] Adding [systemEnvironment] PropertySource with lowest search precedence
2012-07-20 10:19:54,522 DEBUG [org.springframework.core.env.AbstractEnvironment] [http-bio-8080-exec-10] Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
2012-07-20 10:19:54,522 DEBUG [org.springframework.beans.BeanUtils] [http-bio-8080-exec-10] No property editor [org.springframework.web.multipart.MultipartFileEditor] found for type org.springframework.web.multipart.MultipartFile according to 'Editor' suffix convention
2012-07-20 10:19:54,522 DEBUG [org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver] [http-bio-8080-exec-10] Resolving exception from handler [public com.ge.research.sadl.queryserver.webapp.controller.ExecuteQueryResult com.ge.research.sadl.queryserver.webapp.controller.QueryController.executeQuery(java.lang.String,java.lang.String,org.springframework.web.multipart.MultipartFile[],java.lang.String,javax.servlet.http.HttpServletResponse)]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile[]'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found
2012-07-20 10:19:54,522 DEBUG [org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver] [http-bio-8080-exec-10] Resolving exception from handler [public com.ge.research.sadl.queryserver.webapp.controller.ExecuteQueryResult com.ge.research.sadl.queryserver.webapp.controller.QueryController.executeQuery(java.lang.String,java.lang.String,org.springframework.web.multipart.MultipartFile[],java.lang.String,javax.servlet.http.HttpServletResponse)]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile[]'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found
2012-07-20 10:19:54,522 DEBUG [org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver] [http-bio-8080-exec-10] Resolving exception from handler [public com.ge.research.sadl.queryserver.webapp.controller.ExecuteQueryResult com.ge.research.sadl.queryserver.webapp.controller.QueryController.executeQuery(java.lang.String,java.lang.String,org.springframework.web.multipart.MultipartFile[],java.lang.String,javax.servlet.http.HttpServletResponse)]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile[]'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found
2012-07-20 10:19:54,522 DEBUG [org.springframework.web.servlet.DispatcherServlet] [http-bio-8080-exec-10] Null ModelAndView returned to DispatcherServlet with name 'appServlet': assuming HandlerAdapter completed request handling
2012-07-20 10:19:54,522 DEBUG [org.springframework.web.servlet.FrameworkServlet] [http-bio-8080-exec-10] Successfully completed request

[hathawa]

Does anyone have any ideas as to why a null input type="file" element is not getting mapped into a MultipartFile[]?
Also, why is Spring looking for a MultpartFileEditor? Thanks.

Barry

[hathawa]

I figured this out myself. I believe this is a Spring bug. When I specify a method parameter of "@RequestParam(value="file",required=false) MultipartFile[] file"
and no file is attached to the POST then Spring should be able to map the empty request parameter for "file" to null and not throw its hands up. I got around this by removing the parameter from the method and adding a "MultipartHttpServletRequest request" parameter. I then "List<MultipartFile> file = request.getFiles("file");" which correctly sets up "file". I would have thought that the RequestParam annotation could have done the same thing.