js实现分割上传大文件

网络编程 2025/10/29 佚名

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本文实例介绍了js上传文件操作，分享给大家供大家参考，具体内容如下

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="zh-CN">
<head>
<title>分割大文件上传</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style>
 #test{
  width: 200px;
  height: 100px;
  border: 1px solid green;
  display: none;
 }
 #img{
  width: 50px;
  height: 50px;
  display: none;
 }
 #upimg{
  text-align: center;
  font: 8px/10px '微软雅黑','黑体',sans-serif;
  width: 300px;
  height: 10px;
  border: 1px solid green;
 }
 #load{
  width: 0%;
  height: 100%;
  background: green;
  text-align: center;
 }
</style>
</head>
 <body>
  <form enctype="multipart/form-data" action="file.php" method="post">
   <!-- 
   <input type="file" name="pic" />
   <div id="img"></div>
   <input type="button" value="uploadimg" onclick="upimg();" /><br />
   -->
   <div id="upimg">
    <div id="load"></div>
   </div>
   <input type="file" name="mof" multiple="multiple"/>
   <input type="button" value="uploadfile" onclick="upfile();" />
   <input type="submit" value="submit" />
  </form>
  <div id="test">
   测试是否DIV消失
  </div>
<script type="text/javascript">
 var dom=document.getElementsByTagName('form')[0];
 dom.onsubmit=function(){
  //return false;
 }
 var xhr=new XMLHttpRequest();
 var fd;
 var des=document.getElementById('load');
 var num=document.getElementById('upimg');
 var file;
 const LENGTH=10*1024*1024;
 var start;
 var end;
 var blob;
 var pecent;
 var filename;
 //var pending;
 //var clock;
 function upfile(){
  start=0;
  end=LENGTH+start;
  //pending=false;

  file=document.getElementsByName('mof')[0].files[0];
  //filename = file.name;
  if(!file){
   alert('请选择文件');
   return;
  }
  //clock=setInterval('up()',1000);
  up();

 }

 function up(){
  /*
  if(pending){
   return;
  }
  */
  if(start<file.size){
   xhr.open('POST','file.php',true);
   //xhr.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
   xhr.onreadystatechange=function(){
    if(this.readyState==4){
     if(this.status>=200&&this.status<300){
      if(this.responseText.indexOf('failed') >= 0){
       //alert(this.responseText);
       alert('文件发送失败，请重新发送');
       des.style.width='0%';
       //num.innerHTML='';
       //clearInterval(clock);
      }else{
       //alert(this.responseText)
       // pending=false;
       start=end;
       end=start+LENGTH;
       setTimeout('up()',1000);
      }

     }
    }
   }
   xhr.upload.onprogress=function(ev){
    if(ev.lengthComputable){
     pecent=100*(ev.loaded+start)/file.size;
     if(pecent>100){
      pecent=100;
     }
     //num.innerHTML=parseInt(pecent)+'%';
     des.style.width=pecent+'%';
     des.innerHTML = parseInt(pecent)+'%'
    }
   }
　　　　　　　
　　　　　　　//分割文件核心部分slice
   blob=file.slice(start,end);
   fd=new FormData();
   fd.append('mof',blob);
   fd.append('test',file.name);
   //console.log(fd);
   //pending=true;
   xhr.send(fd);
  }else{
   //clearInterval(clock);
  }
 }

 function change(){
  des.style.width='0%';
 }
 
</script>
 </body>
</html>

file.php:

<"text-align: center">