页面设置隐藏的iframe

<iframeid='reqFrame'frameborder='0'style='display:none'allowtransparency='true'></iframe>

页面下载按钮

<aclass="easyui-linkbutton"data-options="iconCls:'icon-ok'"title="/demo/省本部固定资产明细表.xlsx"id="btnDown"href="javascript:void(download('btnDown'))" >下载模板</a>

页面JS脚本

 functiondownload(id){$("#reqFrame").attr("src",encodeURI("/servlet/Common?action=downloadByPath&filePath="+$("#"+id).attr("title")));
}

后台servlet方法

public class SV_Common extendsHttpServlet {/****/private static final long serialVersionUID = 1L;public static final Logger logger = Logger.getLogger(SV_Common.class.getName());protected voidservice(HttpServletRequest request,HttpServletResponse response)throwsServletException, IOException {String action= request.getParameter("action");try{if ("downloadByPath".equals(action)) { //下载指定路径的文件
downloadByPath(request, response);}else{throw new IllegalArgumentException("没有相匹配的操作类型，请检查opp变量.");}}catch(Exception ex) {ex.printStackTrace();}}private voiddownloadByPath(HttpServletRequest request,HttpServletResponse response)throwsIOException, ServletException {String filePath= request.getParameter("filePath");logger.info("filePath="+filePath);String fileFullName= filePath.substring(filePath.lastIndexOf("/") + 1);response.reset();if (request.getHeader("User-Agent").toLowerCase().indexOf("firefox") > 0) {  logger.info("User-Agent=firefox");response.setHeader("Content-Disposition", "attachment;filename=" + new String(fileFullName.getBytes("UTF-8"), "ISO8859-1"));      } else {    logger.info("User-Agent=not firefox");response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileFullName, "UTF-8"));  }        File file= new File(PathUtil.getPath("") + "/" +filePath);response.setContentType(newMimetypesFileTypeMap().getContentType(file));OutputStream out=response.getOutputStream();BufferedInputStream in= null;byte[] buffer = new byte[8192];intlength;try{    in= newBufferedInputStream(new FileInputStream(file),8192);while ( (length = in.read(buffer)) != -1){out.write(buffer,0,length);}        }catch(IOException ex){   ex.printStackTrace();}finally{if (out != null){try{out.close();}catch(IOException ex) {}out= null;}if (in != null){try{in.close();}catch(IOException ex) {}in= null;}}response.flushBuffer(); };
}