Spring portlet form: #ModelAttribute not populated - forms

Question

I am a beginner at Spring and I was wondering why my ModelAttribute did not populate (All the values were null)
I want to create a multipart from that allows me to upload a csv file as well as the type of CSV file too.
My codes are as such:
In the CSVUpload-portlet.xml:
<bean class="org.springframework.web.portlet.mvc.annotation.DefaultAnnotationHandlerMapping"/>
<bean class="org.springframework.web.portlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="100000000"></property>
</bean>
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
CSVUploadPortlet.java (Controller)
*All imports
#Controller("uploadCsvToDatabase")
#RequestMapping(value = "VIEW")
public class CSVUploadPortlet {
private static final Logger log = Logger.getLogger(CSVUploadPortlet.class);
private static IWBCSVUploadRemote csvupload;
#RenderMapping
public String viewCSVUploadBase(Model model, RenderRequest request) {
try {
} catch (Exception e) {
e.printStackTrace();
log.info("problem in retrieving the CSV Upload service" + e);
}
return "csvupload/csvupload_view";
}
#ModelAttribute("csvFileUploadVO")
public CSVFileUploadVO getCommandObject()
{
System.out.println("SpringFileController -> getCommandObject -> Building VO");
return new CSVFileUploadVO();
}
#ActionMapping(params="action=uploadCsvToDatabase")
public void uploadCsvToDatabase(
#ModelAttribute("csvFileUploadVO") CSVFileUploadVO csvFileUploadVO, BindingResult result, ActionRequest request, ActionResponse response, SessionStatus sessionStatus){
try{
System.out.println("FileType:"+csvFileUploadVO.getFileType()); //This returns null
System.out.println("CSVFile Size:"+csvFileUploadVO.getCsvFile().getSize()); //This returns a null-pointer exception
} catch (Exception e) {
log.info("Problem in retrieving the CSVUpload configuration list " + e);
e.printStackTrace();
}
}
}
CSVFileUploadVO.java
import org.springframework.web.multipart.commons.CommonsMultipartFile;
public class CSVFileUploadVO {
private String fileType;
private CommonsMultipartFile csvFile;
private String message;
public CSVFileUploadVO() {
}
public String getFileType() {
return fileType;
}
public void setFileType(String fileType) {
this.fileType = fileType;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public CommonsMultipartFile getCsvFile() {
return csvFile;
}
public void setCsvFile(CommonsMultipartFile csvFile) {
this.csvFile = csvFile;
}
}
Form JSP
All taglibs imported...
<portlet:actionURL var="fileUploadURL">
<portlet:param name="action" value="uploadCsvToDatabase" />
</portlet:actionURL>
<form:form method="post" action="${fileUploadURL}"
commandName="csvFileUploadVO" enctype="multipart/form-data">
<table>
<tbody>
<tr>
<td><label>Department:</label></td>
<td><form:select path="fileType">
<form:option value="BRMAdd" label="BRM Add" />
<form:option value="FOSAdmin" label="FOS Admin" />
<form:option value="FOSRM" label="FOS RM" />
<form:option value="FOSTeam" label="FOS Team" />
<form:option value="ITRelationships" label="IT Relationships" />
<form:option value="HRAttendance" label="HR Attendance" />
<form:option value="iCareCallReport" label="iCare Call Report" />
</form:select></td>
</tr>
<tr>
<td><label>Specify your File:</label></td>
<td><form:input path="csvFile" type="file" /></td>
</tr>
<tr>
<tr>
<td colspan="100%"><input type="submit" value="Submit" /></td>
</tr>
<tr>
<td colspan="100%">${csvFileUploadVO.message}</td>
</tr>
</tbody>
</table>
</form:form>
I know it seems like asking you to help solve a problem for me but I've been stuck on this for 8 hours, reading every resource and stackoverflow website i could google on. But despite that, I wasn't able to find anything.
Thank you for your help in this.

Answer 1

You will want to look at http://static.springsource.org/spring/docs/3.0.x/reference/mvc.html#mvc-multipart-resolver particularly the RequestMapping where the parameter is MultipartFile
#RequestMapping(value = "/form", method = RequestMethod.POST)
public String handleFormUpload(#RequestParam("name") String name,
#RequestParam("file") MultipartFile file) {

Answer 2

You have to define the ModelAttribute in your JSP form, something like this:
<form:form method="post" action="${fileUploadURL}"
modelAttribute="csvFileUploadVO" enctype="multipart/form-data">

Answer 3

Liferay 6.0.5 and Spring 3.2.2.RELEASE:
I tried with editing spring classes, but there is much easier solution to this problem. Just check whether your CommonsPortletMultipartResolver really has been initilized. The fact that it is declared in spring.xml does not mean that it is loaded.
If it is not initialized, than the file part of the request would never be converted to CommonsMultipartFile because your request would not be a commons Multipart request.
CommonsPortletMultipartResolver will be invoked by org.springframework.web.portlet.DispatcherPortlet lifecycle if it is loaded and spring uses this class.

Answer 4

Your multipart resolver must have the id portletMultipartResolver and be of type org.springframework.web.portlet.multipart.CommonsPortletMultipartResolver
<bean id="portletMultipartResolver" class="org.springframework.web.portlet.multipart.CommonsPortletMultipartResolver">
</bean>