spring mvc导入excel

前台jsp:
<form id="importExcelForm" name="importExcelForm" method="post" novalidate enctype="multipart/form-data">
	<input type="hidden" name="aid" id="aid" value="${aid}">
	<input type="hidden" name="url" id="url" value="<%=request.getContextPath()%>/aaa/aaaController.do?importExcel">
	<table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0" class="vxi_crm_inputtable">
	   <tr>
	      <td>
		&nbsp;&nbsp;<vxi:i18n keyword="" options="{zh:'选择文件:',en:'File:'}"/>
		<input id="dataPortAttachment" type="file" name="attachment" class="easyui-validatebox" required="true"/>
	      </td>
	   </tr>
	</table>
</form>

后台java：
@RequestMapping(params={"importExcel"})
public void importExcel(
	HttpServletRequest request,
	HttpServletResponse response,
	@RequestParam("attachment") CommonsMultipartFile[] sourceFile) {
	if (sourceFile == null ||sourceFile.length==0) {
			return ;
	}
    	CommonsMultipartFile singleFile=sourceFile[0];
    	JSONObject json = new JSONObject();
	/*随机文件名*/
	Random rand = new Random();
	int random = rand.nextInt();
	random = random > 0 ? random : (-1) * random;// 随机负数转为正数
	Date date = new Date();
	SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
	String currentTime = sdf.format(date);
	if(singleFile.getOriginalFilename().indexOf(".")==-1){
		json.put("success", false);
		renderJson(response,json.toString());
		return;
	}
	String attachmentFileName = singleFile.getOriginalFilename(); // 原始文件名
	String attachmentContentType = attachmentFileName.substring(attachmentFileName.lastIndexOf("."));
	// 设置文件名(新文件名 = 当前时间 + 随机数 + 上传文件的后缀名)
	String newFileName = currentTime + random
			+ singleFile.getOriginalFilename().substring(singleFile.getOriginalFilename().lastIndexOf("."));
	/* 设置上传文件的保存路径 */
	// 获取web服务器工作路径
	String realPath = request.getServletContext().getRealPath("/excel/import");
	// 文件的存放位置 = web服务器中项目的images路径  +新文件名
	File destinationFile = new File(realPath + "/" +newFileName);
	try {
		// 将上传文件拷贝到web服务器
		InputStream in = singleFile.getInputStream();  
		FileUtils.copyInputStreamToFile(in, destinationFile);
	} catch (IOException e) {
		json.put("success", false);
		renderJson(response,json.toString());
		return;
	}
}