本文实例为大家分享了SpringMvc3+extjs4实现上传与下载的具体代码，供大家参考，具体内容如下

最近生活过的很充实，人一直在不停的忙碌着学习新东西。这是我最近遇到的问题，我找度娘n了很久，终于找到了解决方案！

前台代码:

<script> Ext.onReady(function() { Ext.create('Ext.form.Panel', { title : '文件上传', width : 400, bodyPadding : 10, frame : true, renderTo : document.body, items : [ { xtype : 'filefield', name : '文件', fieldLabel : 'File', labelWidth : 50, msgTarget : 'side', allowBlank : false, anchor : '100%', buttonText : '请选择文件...' } ], buttons : [ { text : '上传', handler : function() { var form = this.up('form').getForm(); if (form.isValid()) { form.submit({ url : '根路径/fileUploadDown/fileUpload', waitMsg : '正在上传文件中...', success : function(fp, o) { Ext.Msg.alert('上传文件成功!'); } }); } } } ] }); });</script>

后台代码：

/***记录返回结果*/ class ExtJSFormResult { private boolean success; public boolean isSuccess() { return success; } public void setSuccess(boolean success) { } public String toString() { return "{success:" + this.success + "}"; }} class FileUploadBean { private CommonsMultipartFile file; public CommonsMultipartFile getFile() { return file; } public void setFile(CommonsMultipartFile file) { this.file = file; }}/** * 文件的上传与下载 * @author Administrator * */@Controller@RequestMapping(value = "/fileUploadDown")public class FileUploadAndDownController { private static int countter=1; //定义一个计数器,用于上传文件的重命名 @Autowired private ProAnnexDao<ProAnnex> proAnnextDao; public void setProAnnextDao(ProAnnexDao<ProAnnex> proAnnextDao) { this.proAnnextDao = proAnnextDao; } @RequestMapping(value="fileUpload",method = RequestMethod.POST) public @ResponseBody String create(RedirectAttributes redirectAttributes,FileUploadBean uploadItem, BindingResult result,HttpSession session){ //获取根路径 String uploadFolderPath = session.getServletContext().getRealPath("/"); ExtJSFormResult extjsFormResult = new ExtJSFormResult(); try { if (result.hasErrors()) { for (ObjectError error : result.getAllErrors()) { System.err.println("Error: " + error.getCode() + " - " + error.getDefaultMessage()); } // 设置ExtJS返回 - error extjsFormResult.setSuccess(false); return extjsFormResult.toString(); } MultipartFile file = uploadItem.getFile(); String fileName = null; InputStream inputStream = null; OutputStream outputStream = null; if(file.getSize()>0){ System.out.println("File Size:::" + file.getSize()); if(file.getSize()>5242880){ System.out.println("File Size:::" + file.getSize()); extjsFormResult.setSuccess(false); return "error"; } inputStream = file.getInputStream(); File newFile = new File(uploadFolderPath + "fileUpload/"); //如果文件路径不存在就新建一个 if(!newFile.exists()){ newFile.mkdirs(); } //获取文件名 String name=file.getOriginalFilename(); //从数据库中查询存在此类文件名否 Long count=proAnnextDao.isRepeatName(name); //如果存在一样的文件名,就进行从命名 if (count>0) { name=name.substring(0, name.lastIndexOf("."))+"("+(countter++)+")"+name.substring(name.lastIndexOf(".")); } fileName = uploadFolderPath + "fileUpload/" + name; outputStream = new FileOutputStream(fileName); int readBytes = 0; byte[] buffer = new byte[10000]; while ((readBytes = inputStream.read(buffer, 0, 10000)) != -1) { outputStream.write(buffer, 0, readBytes); } outputStream.close(); inputStream.close(); } // 设置ExtJS返回 - sucsess extjsFormResult.setSuccess(true); } catch (Exception e) { e.printStackTrace(); // 设置ExtJS返回 - error extjsFormResult.setSuccess(false); } return extjsFormResult.toString(); } }

springMvc.xml（此文件名可能跟项目的实际情况有区别）中的配置:

<!-- 上传文件,限制大小的配置 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!--resolveLazily属性启用是为了推迟文件解析，以便在Upload中捕获文件大小异常--> <property name="resolveLazily" value="true"/> <property name="maxUploadSize" value="5242880" /> </bean> <!-- 将无法mapping到Controller的path交给default servlet handler处理 --> <mvc:default-servlet-handler/><!-- 使用默认的servlet来响应静态文件 --> <!-- 文件的上传与下载 --> <mvc:view-controller path="/" view-name="redirect:/fileUploadDown"/>

以上的就是上传文件了。

那下载呢？

下载比较简单,代码如下：

@RequestMapping("/downloadFile") public void download(@Valid @ModelAttribute("downLoadName") String downLoadName, HttpServletResponse response,HttpSession session,BindingResult result,HttpServletRequest request) throws IOException { response.setCharacterEncoding("UTF-8"); request.setCharacterEncoding("UTF-8"); //获取文件的路径 String url=session.getServletContext().getRealPath("/")+"/fileUpload/"+downLoadName; System.out.println(url); File file=new File(url); InputStream input = FileUtils.openInputStream(file); byte[] data = IOUtils.toByteArray(input); //System.out.println("文件名:"+downLoadName); response.reset(); //设置响应的报头信息(中文问题解决办法) response.setHeader("content-disposition","attachment;fileName="+URLEncoder.encode(downLoadName, "UTF-8")); response.addHeader("Content-Length", "" + data.length); response.setContentType("application/octet-stream; charset=UTF-8"); IOUtils.write(data, response.getOutputStream()); IOUtils.closeQuietly(input); }

在界面上只要有一个连接地址：如:window.location.href="根路径/fileUploadDown/downfile/downLoadName="+name;这样就可以下载了.... 超连接的写法基本一样,这里就不多说了.

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。