Attempting to allow user to upload a file, but getting Null Pointer Exception

**sukmul** · Mar 7th, 2013, 10:33 AM

Hey all,

I've posted the full question on StackOverflow.com at the following link. Since the need for a solution is urgent, I decided that I should post it on this forum as well. Thanks for taking the time to look.

http://stackoverflow.com/questions/1...ing-spring-mvc

Regardless, this is my setup...

MODEL

Code:

public class UploadForm {

private CommonsMultipartFile fileData;

public CommonsMultipartFile getFileData() {
    System.out.println("REACHED GET METHOD");
    return fileData;
}
public void setFileData(CommonsMultipartFile fileData) {
    System.out.println("REACHED SET METHOD");
    this.fileData = fileData;
}
}

VIEW

Code:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<%@ page session="false" %>
<html>
<head>
<title>Upload Document</title>
    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
    <script type="text/javascript">     

    </script>
    <script type="text/javascript" src="resources/rulesextractor.js"></script>
    <link rel="stylesheet" type="text/css" href="./resources/css/rulesextractor.css" />     
</head>
<body>
<c:import url = "./header.jsp">
    <c:param name = "title" value = "Upload Document"/>
    <c:param name = "region" value = "${region}"/>
</c:import>
<br>
    Please choose a Document to upload
<br>

<form:form method="POST" modelAttribute="uploadForm" commandName="uploadForm" name="uploadForm" id="uploadForm" enctype="multipart/form-data">
    <form:input path="fileData" name="fileData" type="file"/>
<br>
    <input type="submit" name="submit" value="Submit" id="subbtn"/>
    <input type="button" value="Main Menu" onclick="back();"/>
</form:form>

</body>
</html>

CONTROLLER

Code:

@Controller
public class UploadController extends BaseController {
private static final Logger logger = LoggerFactory.getLogger(FlowController.class);

//@Autowired
//private UserPreferences userPreferences;  

@Autowired 
GenericSearchBO genericSearchBO;

@RequestMapping(value = "upload", method = RequestMethod.GET)
public String getUploadPage(Model m){
    logger.info("UploadController: Getting Upload page");
    updateRegionOnModel(m);
    m.addAttribute(new UploadForm());
    return "/pages/upload";
}
@RequestMapping(method = RequestMethod.POST)
public String create(@Valid UploadForm UploadForm, BindingResult result){
    if (result.hasErrors())
    {
      for(ObjectError error : result.getAllErrors())
      {
        System.err.println("Error: " + error.getCode() +  " - " + error.getDefaultMessage());
      }
      return "/pages/upload";
    }

    // Some type of file processing...
    System.err.println("-------------------------------------------");
    //.getOriginalFilename()
    System.err.println("Test upload: " + UploadForm.getFileData());
    System.err.println("-------------------------------------------");

    return "redirect:/pages/upload";
}
}

The issue here is that I am in fact entering the Controller's public String create(@Valid UploadForm UploadForm, BindingResult result) method, but UploadForm is being passed as a null value and I can't, for the life of me, figure it out and it's getting quite frustrating. I do not believe that the file that the user is uploading is being passed to the model using the set method. THe reason I belive this is because the get method's

Code:

System.out.println("REACHED GET METHOD");

is being reached, but the model's set method's

Code:

System.out.println("REACHED SET METHOD");

is not.

**sukmul** · Mar 8th, 2013, 03:37 PM

This issue has yet to be resolved, so any suggestions will be greatly appreciated!

Thread: Attempting to allow user to upload a file, but getting Null Pointer Exception

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