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
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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;
}
