jquery.fileDownload.js插件导出excel

因为使用ajax导出excel会出现问题，所以现在使用jQuery.fileDownload.js插件来解决导出excel的问题

http://johnculviner.com/jquery-file-download-plugin-for-ajax-like-feature-rich-file-downloads/

在页面引入jquery.fileDownload.js插件

1、如下所示

<script type="text/JavaScript" src="${resource}/js/jquery.fileDownload.js"/></script> <script type="text/javascript">  $("#export_confirm").on("click",function(){  var url="${path}/admin/information/student/export";  $.fileDownload(url,{   data:{semesterId:$("#misSemester").val()},   prepareCallback：function(url){    alert("正在导出,请稍后...");   },   successCallback: function(url){    alert("导出完成！");   },   failCallback: function (html, url) {    alert("导出失败，未知的异常。");    }    });     });

jquery-file-Download.js源码解析：

onPrepare: function (url) {     //preparingMessageHtml属性存在,弹出导出准备提示框     if (settings.preparingMessageHtml) {         //jueryUi dialog 可自己修改成其它的。         $preparingDialog = $("<div>").html(settings.preparingMessageHtml).dialog(settings.dialogOptions);     } else if (settings.prepareCallback) {         //调用回调函数         settings.prepareCallback(url);     } }， //导出失败调用的函数 onFail: function (responseHtml, url, error) {     //准备提示对话框存在则关闭     if ($preparingDialog) {         $preparingDialog.dialog('close');     }     //failMessageHtml存在弹出对话框提示     if (settings.failMessageHtml) {         $("<div>").html(settings.failMessageHtml).dialog(settings.dialogOptions);     }      //调用回调函数     settings.failCallback(responseHtml, url, error);     deferred.reject(responseHtml, url); }

2、在后台代码中设置Cookie，并返回Cookie的值

public void export(final HttpServletRequest request, HttpServletResponse response,final String semesterId) throws IOException, IllegalArgumentException, IllegalAccessException {
  String fileName = "excel文件";
  response.reset();
  response.setContentType("application/vnd.ms-excel;charset=utf-8");
  response.setHeader("Content-Disposition", "p_w_upload;filename=" + new String((fileName + ".xls").getBytes(), "iso-8859-1"));

  //在这里加入设置Cookie   -------------
  Cookie fileDownload=new Cookie("fileDownload", "true");
  fileDownload.setPath("/");
  response.addCookie(fileDownload);

  //------------------------------------
  ServletOutputStream out = response.getOutputStream();
  final HSSFWorkbook workbook = new HSSFWorkbook();
  List<Future<Boolean>> resultList = new ArrayList<Future<Boolean>>();

3、如果要使回调函数successCallback和failCallback起作用，还得在后台代码中返回Cookie

 jquery-file-Download.js源码解析：

  后台设置与特定的cookie值

  前台js定时去调用checkFileDownloadComplete方法,检查前台与后台返回的cookie值是否匹配

//check if the file download has completed every checkInterval ms setTimeout(checkFileDownloadComplete, settings.checkInterval); function checkFileDownloadComplete() {     //has the cookie been written due to a file download occuring?     var cookieValue = settings.cookieValue;     if(typeof cookieValue == 'string') {         cookieValue = cookieValue.toLowerCase();     }     var lowerCaseCookie = settings.cookieName.toLowerCase() + "=" + cookieValue;     if (document.cookie.toLowerCase().indexOf(lowerCaseCookie) > -1) {         //execute specified callback         internalCallbacks.onSuccess(fileUrl);         //remove cookie         var cookieData = settings.cookieName + "=; path=" + settings.cookiePath + "; expires=" + new Date(0).toUTCString() + ";";         if (settings.cookieDomain) cookieData += " domain=" + settings.cookieDomain + ";";         document.cookie = cookieData;         //remove iframe         cleanUp(false);         return;     }