ajax异步实现文件分片上传实例代码

<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>JS分片上传-极速上传</title></head><body> <input type="file" name="slice" id="slice" >  <div id="output"><!-- 信息存放地 --> </div><br/></body><script src="http://libs.baidu.com/jquery/1.8.3/jquery.min.js"></script><script type="text/javascript"> $("#slice").change(function(event) {  var file = $("#slice")[0].files[0];var name = file.name;//进行初始化$.ajax({     type:"POST", //请求方式     url:"http://localhost:8080/getuploadId",async: false,    dataType:"json", //返回数据类型    data:{//请求参数    fileName:name,    },    success:function(data){ //请求成功后        console.log("data.code="+JSON.stringify(data));console.log("data.data.objectName="+data.data.objectName);console.log("data.data.uploadId="+data.data.uploadId);var objectName=data.data.objectName;var uploadId=data.data.uploadId;//成功后执行分段上传PostFile(file,0,objectName,uploadId);//合并combineFile(objectName,uploadId); },    error:function (){    alert("系统出现异常！");    flag=false;    } });    }); //执行分片上传 function PostFile(file,i,objectName,uploadId){  var name = file.name,       //文件名   size = file.size,       //总大小shardSize = 2 * 1024 * 1024,   shardSize = 1 * 1024 * 1024,    //以2MB为一个分片,每个分片的大小   shardCount = Math.ceil(size / shardSize); //总片数  if(i >= shardCount){   return;  }  //console.log(size,i+1,shardSize); //文件总大小，第一次，分片大小//  var start = i * shardSize;  var end = start + shardSize;  var packet = file.slice(start, end); //将文件进行切片// 分段号var partNumber = i + 1;  /* 构建form表单进行提交 */  var form = new FormData();  form.append("fileId", '001')  form.append("data", packet); //slice方法用于切出文件的一部分//   form.append("lastModified", file.lastModified); //最后的额修改时间  form.append("name", name);  form.append("totalSize", size);form.append("uploadId", uploadId);form.append("objectName", objectName);form.append("mainFile", packet);form.append("total", shardCount);form.append("sortNumber", partNumber);//uploadId:uploadId,//objectName:objectName,//mainFile:blob,//total:partCount,//sortNumber:partNumber  if(shardCount === i+1){   shardSize = size - i * shardSize  }  form.append("shardSize", shardSize);  form.append("total", shardCount); //总片数  form.append("index", i + 1); //当前是第几片  $.ajax({   // header: {   //  web_token: "cpBvqWrr0UK9zPJoKj+412alxxcY6qFwrSVoO0juZg0S1jX/sGfMd9oi3AsSxW+MdWFrwtGCykUTmMqrqpbCElmT75DfB87lENC7lCuMxgF0d5wQB6yAubUVyGOzhbrScvIfD8ZSjOJ3D88AOy2xRd4oG8TxeGoMoZqnqIwjKg="   // },   url: "http://localhost:8080/multipartupload",   type: "POST",   data: form,   //timeout:"10000", //超时10秒   async: false, //同步   dataType:"json",   processData: false, //很重要，告诉jquery不要对form进行处理   contentType: false, //很重要，指定为false才能形成正确的Content-Type   success: function (data) {    console.log("data="+JSON.stringify(data));    /* 表示上一块文件上传成功，继续下一次 */    if (data.data.code == 1) {     form = '';     i++;     PostFile(file, i,objectName,uploadId);    } else if (data.data.code == 502) {     form = '';     /* 失败后，每2秒继续传一次分片文件 */     setInterval(function () { PostFile(file, i,objectName,uploadId) }, 2000);    } else if (data.data.code == 200) {     console.log("上传成功");    } else if (data.data.code == 500) {     console.log('第'+msg.i+'次，上传文件有误！');    } else {     console.log('未知错误');    }   }  }) }//合并function combineFile(objectName,uploadId){console.log("objectName="+objectName);console.log("uploadId="+uploadId);var object=new Object();object.objectName=objectName;object.uploadId=uploadId; $.ajax({       headers: {Accept: "application/json; charset=utf-8"},type:"POST", //请求方式 url:"http://localhost:8080/combine",async: false,contentType:"application/json",dataType:"json", //返回数据类型data:JSON.stringify(object),success:function(data){ //请求成功后    console.log("data="+JSON.stringify(data));console.log("data.data.code="+data.data.code);console.log("data.data.url="+data.data.url);},error:function (){alert("系统出现异常！");flag=false;} }); }</script></html>