views:

318

answers:

2

Hello,

MaxUploadSizeExceededException exception appears when I upload a file whose size exceeds the maximum allowed. I want to show an error message when this exception appears (like a validation error message). How can I handle this exception to do something like this in Spring 3?

Thanks.

A: 

Have a look at the HandlerExceptionResolver: http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/mvc.html#mvc-exceptionhandlers

Thomas Vanstals
Yes.. But does this still enable you to show an user-friendly validation message at the **same** form?
BalusC
You can redirect to the same view and manually add an error message in the model.
Thomas Vanstals
But what about if I have more than one form?, I can't know in advance which view is the one I should return.
Javi
You mean more than one form in a view ?
Thomas Vanstals
@Thomas, I have the same scenario. Having multiple form is a JSP View. Is this still possible?
Mark Estrada
A: 

Since I didn't find a good answer on this and I finally figured it out a solution that works using a HandlerExceptionResolver, I decided I would post it in case it would help anybody else.

============ Add multipart resolver to your Spring config ============    
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">    
   <!--  the maximum size of an uploaded file in bytes -->
   <!-- <property name="maxUploadSize" value="10000000"/> -->
   <property name="maxUploadSize" value="1000"/>
</bean>   
=======================================================================

=================== Model  - UploadedFile.java ========================= 
package com.mypkg.models;

import org.springframework.web.multipart.commons.CommonsMultipartFile;

public class UploadedFile
{
    private String title;

    private CommonsMultipartFile fileData;

    public String getTitle()
    {
        return title;
    }

    public void setTitle(String title)
    {
        this.title = title;
    }

    public CommonsMultipartFile getFileData()
    {
        return fileData;
    }

    public void setFileData(CommonsMultipartFile fileData)
    {
        this.fileData = fileData;
    }

}
========================================================================

=================== View  - /upload.jsp ========================= 
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%&gt;
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%&gt;
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
    <head>
        <title>Test File Upload</title>
    </head>
    <body>
        <h1>Select a file to upload</h1>
        <c:if test="${not empty errors}">
            <h2 style="color:red;">${errors}.</h2>
        </c:if>
        <form:form modelAttribute="uploadedFile" method="post" enctype="multipart/form-data" name="uploadedFileform" id="uploadedFileform">
            <table width="600" border="0" align="left" cellpadding="0" cellspacing="0" id="pdf_upload_form">
                <tr>
                    <td width="180"><label class="title">Title:</label></td>
                    <td width="420"><form:input id="title" path="title" cssClass="areaInput" size="30" maxlength="128"/></td>
                </tr>
                <tr>
                    <td width="180"><label class="title">File:</label></td>
                    <td width="420"><form:input id="fileData" path="fileData" type="file" /></td>
                 </tr>
                 <tr>
                    <td width="180"></td>
                    <td width="420"><input type="submit" value="Upload File" /></td>
                 </tr>
            </table>
        </form:form>
    </body>
</html>

========================================================================

=================== Controller  - FileUploadController.java ============
 package com.mypkg.controllers;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MaxUploadSizeExceededException;
import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;

import com.mypkg.models.UploadedFile;

@Controller
public class FileUploadController  implements HandlerExceptionResolver
{
    @RequestMapping(value = "/upload", method = RequestMethod.GET)
    public String getUploadForm(Model model)
    {
        model.addAttribute("uploadedFile", new UploadedFile());
        return "/upload";
    }

    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    public String create(UploadedFile uploadedFile, BindingResult result)
    {
        // Do something with the file
        System.out.println("#########  File Uploaded with Title: " + uploadedFile.getTitle());
        System.out.println("#########  Creating local file: /var/test-file-upload/" + uploadedFile.getFileData().getOriginalFilename());

        try
        {

            InputStream in = uploadedFile.getFileData().getInputStream();
            FileOutputStream f = new FileOutputStream(
                    "/var/test-file-upload/" + uploadedFile.getFileData().getOriginalFilename());
            int ch = 0;
            while ((ch = in.read()) != -1)
            {
                f.write(ch);
            }
            f.flush();
            f.close();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }

        return "redirect:/";
    }

    /*** Trap Exceptions during the upload and show errors back in view form ***/
    public ModelAndView resolveException(HttpServletRequest request,
            HttpServletResponse response, Object handler, Exception exception)
    {        
        Map<Object, Object> model = new HashMap<Object, Object>();
        if (exception instanceof MaxUploadSizeExceededException)
        {
            model.put("errors", exception.getMessage());
        } else
        {
            model.put("errors", "Unexpected error: " + exception.getMessage());
        }
        model.put("uploadedFile", new UploadedFile());
        return new ModelAndView("/upload", (Map) model);
    }

}

========================================================================
Steve Davis