$(function(){
  $.each($(".preview"),function(i,item){
    var _obj=$(item);
    var ext=getExt(_obj.attr("data-url"));
    if(ext == '.pdf'){
      var frame=_obj.parent().next(".preview-frame");
      frame.attr("src", "/js/pdfjs/web/viewer.html?file=" + _obj.attr("data-url"));
      frame.addClass("load");
      frame.slideToggle();
    };
  });
  
});

//获取文件后缀
function getExt(url){
  var point = url.lastIndexOf(".");
  var type = url.substr(point);
  return type ;
};