這篇文章介紹的內容是關於js php分片上傳大文件，有著一定的參考價值，現在分享給大家，有需要的朋友可以參考一下
1.理解部分
服務端為什麼不能直接傳大檔案？跟php.ini裡面的幾個配置有關
upload_max_filesize = 2M //PHP最大能接受的文件大小 post_max_size = 8M //PHP能收到的最大POST值' memory_limit = 128M //内存上限 max_execution_time = 30 //最大执行时间
當然不能簡單粗暴的把上面幾個值調大，否則伺服器記憶體資源吃光是遲早的問題。
好在HTML5開放了新的FILE API，也可以直接操作二進位對象，我們可以直接在瀏覽器端實作檔案切割，依照以前的做法就得用Flash的方案，實現起來會麻煩很多。
JS思路
1.監聽上傳按鈕的onchange事件
2.取得檔案的FILE物件
3.把檔案的FILE物件進行切割，並且附加到FORMDATA物件中
4.把FORMDATA物件透過AJAX傳送到伺服器
5.重複3、4步驟，直到檔案傳送完。
PHP想法
1.建立上傳資料夾
2.把檔案從上傳臨時目錄移動到上傳資料夾
3.所有的資料區塊上傳完成後，進行檔案合成
4.刪除資料夾
5.返回上傳後的檔案路徑
#2.html部分
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
#progress{
width: 300px;
height: 20px;
background-color:#f7f7f7;
box-shadow:inset 0 1px 2px rgba(0,0,0,0.1);
border-radius:4px;
background-image:linear-gradient(to bottom,#f5f5f5,#f9f9f9);
}
#finish{
background-color: #149bdf;
background-image:linear-gradient(45deg,rgba(255,255,255,0.15) 25%,transparent 25%,transparent 50%,rgba(255,255,255,0.15) 50%,rgba(255,255,255,0.15) 75%,transparent 75%,transparent);
background-size:40px 40px;
height: 100%;
}
form{
margin-top: 50px;
}
</style>
</head>
<body>
<p id="progress">
<p id="finish" style="width: 0%;" progress="0"></p>
</p>
<form action="">
<input type="file" name="file" id="file">
<input type="button" value="停止" id="stop">
</form>
<script>
var fileForm = document.getElementById("file");
var stopBtn = document.getElementById('stop');
var upload = new Upload();
fileForm.onchange = function(){
upload.addFileAndSend(this);
}
stopBtn.onclick = function(){
this.value = "停止中";
upload.stop();
this.value = "已停止";
}
function Upload(){
var xhr = new XMLHttpRequest();
var form_data = new FormData();
const LENGTH = 1024 * 1024;
var start = 0;
var end = start + LENGTH;
var blob;
var blob_num = 1;
var is_stop = 0
//对外方法，传入文件对象
this.addFileAndSend = function(that){
var file = that.files[0];
blob = cutFile(file);
sendFile(blob,file);
blob_num += 1;
}
//停止文件上传
this.stop = function(){
xhr.abort();
is_stop = 1;
}
//切割文件
function cutFile(file){
var file_blob = file.slice(start,end);
start = end;
end = start + LENGTH;
return file_blob;
};
//发送文件
function sendFile(blob,file){
var total_blob_num = Math.ceil(file.size / LENGTH);
form_data.append('file',blob);
form_data.append('blob_num',blob_num);
form_data.append('total_blob_num',total_blob_num);
form_data.append('file_name',file.name);
xhr.open('POST','http://www.test3.com/fenpian/upload.php',false);
xhr.onreadystatechange = function () {
if (xhr.readyState==4 && xhr.status==200)
{
console.log(xhr.responseText);
console.log(5555555555);
}
var progress;
var progressObj = document.getElementById('finish');
if(total_blob_num == 1){
progress = '100%';
}else{
progress = Math.min(100,(blob_num/total_blob_num)* 100 ) +'%';
console.log(progress);
console.log('分割');
}
progressObj.style.width = progress;
var t = setTimeout(function(){
if(start < file.size && is_stop === 0){
blob = cutFile(file);
sendFile(blob,file);
blob_num += 1;
}else{
setTimeout(t);
}
},1000);
}
xhr.send(form_data);
}
}
</script>
</body>
</html>3.php部分
<?php
class Upload{
private $filepath = './upload'; //上传目录
private $tmpPath; //PHP文件临时目录
private $blobNum; //第几个文件块
private $totalBlobNum; //文件块总数
private $fileName; //文件名
public function __construct($tmpPath,$blobNum,$totalBlobNum,$fileName){
$this->tmpPath = $tmpPath;
$this->blobNum = $blobNum;
$this->totalBlobNum = $totalBlobNum;
$this->fileName = $fileName;
$this->moveFile();
$this->fileMerge();
}
//判断是否是最后一块，如果是则进行文件合成并且删除文件块
private function fileMerge(){
if($this->blobNum == $this->totalBlobNum){
$blob = '';
for($i=1; $i<= $this->totalBlobNum; $i++){
$blob = file_get_contents($this->filepath.'/'. $this->fileName.'__'.$i);
file_put_contents($this->filepath.'/'. $this->fileName,$blob,FILE_APPEND);
}
$this->deleteFileBlob();
}
}
//删除文件块
private function deleteFileBlob(){
for($i=1; $i<= $this->totalBlobNum; $i++){
@unlink($this->filepath.'/'. $this->fileName.'__'.$i);
}
}
//移动文件
private function moveFile(){
$this->touchDir();
$filename = $this->filepath.'/'. $this->fileName.'__'.$this->blobNum;
move_uploaded_file($this->tmpPath,$filename);
}
//API返回数据
public function apiReturn(){
if($this->blobNum == $this->totalBlobNum){
if(file_exists($this->filepath.'/'. $this->fileName)){
$data['code'] = 2;
$data['msg'] = 'success';
$data['file_path'] = 'http://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['DOCUMENT_URI']).str_replace('.','',$this->filepath).'/'. $this->fileName;
}
}else{
if(file_exists($this->filepath.'/'. $this->fileName.'__'.$this->blobNum)){
$data['code'] = 1;
$data['msg'] = 'waiting for all';
$data['file_path'] = '';
}
}
header('Content-type: application/json');
echo json_encode($data);
}
//建立上传文件夹
private function touchDir(){
if(!file_exists($this->filepath)){
return mkdir($this->filepath);
}
}
}
//实例化并获取系统变量传参
$upload = new Upload($_FILES['file']['tmp_name'],$_POST['blob_num'],$_POST['total_blob_num'],$_POST['file_name']);
//调用方法，返回结果
$upload->apiReturn();3.偵錯中遇到的php.ini設定的問題
3.1
post_max_size = 10M：
3.2 max_file_uploads:20
3.3
memory_limit：128M;(解释：php页面消耗的最大内存)
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