<form id="input" action="importExcel.jhtml" method="post" enctype="multipart/form-data" target="hiddenIFrame">
　　<input id="excelFile" name="file" type="file" />
　　<input type="submit" class="button" value="导入excel"/>
</form>
<iframe id='hiddenIFrame' name='hiddenIFrame' style="display:none;"></iframe>

$(function(){
  $("#hiddenIFrame").load(function(){
    var wnd = this.contentWindow;
    var str = $(wnd.document.body).html();
    callback(str);
  });
})
 
function callback(info){
  alert(info);
}