JQUERY不请求文件，只请求文件大小的方法 原

<a href="001.html" class="fetchSize">FirstTrickshot</a> <br /> 
<a href="034.html" class="fetchSize">This Trickshot</a> <br /> 
<a href="assets/img/ball.png" class="fetchSize">Ball.png</a> <br />
 <script>
// Loop all .fetchSize links
$('a.fetchSize').each(function(){
 
    // Issue an AJAX HEAD request for each one
    var link = this;
 
    $.ajax({
        type        : 'HEAD',
        url            : link.href,
        complete    : function(xhr){
 
            // Append the filesize to each
            $(link).append(' (' + humanize(xhr.getResponseHeader('Content-Length')) + ')');
 
        }
    });
 
});
 
 
function humanize(size){
    var units = ['bytes','KB','MB','GB','TB','PB'];
 
    var ord = Math.floor( Math.log(size) / Math.log(1024) );
    ord = Math.min( Math.max(0,ord), units.length-1);
 
    var s = Math.round((size / Math.pow(1024,ord))*100)/100;
    return s + ' ' + units[ord];
}
 </script>