如何处理MaxUploadSizeExceededException

小编典典

如何处理MaxUploadSizeExceededException

spring-mvc

MaxUploadSizeExceededException当我上传的文件大小超过允许的最大值时，会出现异常。我想在出现此异常时显示一条错误消息（如验证错误消息）。如何在Spring
3中处理此异常以执行类似的操作？

谢谢。

阅读 646

2020-06-01

共1个答案

小编典典

我终于找到了一个使用HandlerExceptionResolver的解决方案。

将多部分解析器添加到您的Spring配置中 ：

<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>

模型-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;
    }

}

查看-/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"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@ 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>

控制器 -FileUploadController.java：包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<String, Object> model = new HashMap<String, 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", model);
    }

}

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

2020-06-01