PHP+JS实现文件分块上传的示例代码

<input type="file" id="file">
<input type="button" id="upload" value="上传">
<input type="button" id="stop" value="停止">
<input type="button" id="restart" value="继续上传">
上传进度：<span id="progress"></span>

//获取节点
var fileForm = document.getElementById("file");
var uploadBtn = document.getElementById('upload');
var stopBtn = document.getElementById('stop');
var restartBtn = document.getElementById('restart');
//定义常量
const LENGTH = 100 * 1024;//每个上传的文件块大小(100KB)
var start = 0;
var end = LENGTH + start;
var blob;
var is_stop = 0;
var blob_num = 1;
var file = null;
var upload_instance = new Upload();
//上传事件
uploadBtn.onclick = function () {
   upload_instance.addFileAndSend(fileForm);
   return false;
}
stopBtn.onclick = function () {
   upload_instance.stop();
   return false;
}
restartBtn.onclick = function () {
   upload_instance.start();
   return false;
}
function Upload() {
    //判断浏览器类型
    if (window.XMLHttpRequest){
        //IE7+, Firefox, Chrome, Opera, Safari
        var xhr=new XMLHttpRequest();
    }else{
        //IE6, IE5
        var xhr=new ActiveXObject("Microsoft.XMLHTTP");
    }
   //上传文件
   this.addFileAndSend = function (that) {
       file = that.files[0];
       blob = cutFile(file);
       //上传
       uploadFile(blob, file);
       blob_num += 1;
   }
   //停止文件上传
   this.stop = function () {
       xhr.abort();
       is_stop = 1;
   }
   this.start = function () {
       uploadFile(blob, file);
       is_stop = 0;
   }
   //切割文件
   function cutFile(file) {
       var file_blob = file.slice(start, end);
       start = end;
       end = start + LENGTH;
       return file_blob;
   };
    //上传文件
    function uploadFile(blob, file) {
        var form_data = new FormData();
        var total_blob_num = Math.ceil(file.size / LENGTH);
        //上传文件信息
        form_data.append('file', blob);
        //上传的第几个文件块
        form_data.append('blob_num', blob_num);
        //总文件块数
        form_data.append('total_blob_num', total_blob_num);
        //文件名称
        form_data.append('file_name', file.name);
        
        
        //上传
        xhr.open('POST', './test.php', false);
        xhr.onreadystatechange = function () {
            //获取上传进度
            if (total_blob_num == 1) {
                progressText = '100%';
            } else {
                progressText = (Math.min(100, (blob_num / total_blob_num) * 100)).toFixed(2) + '%';
            }
            var progress = document.getElementById('progress');
            progress.innerHTML = progressText;
            
            //循环执行上传，直到所有文件块上传完成
            var t = setTimeout(function () {
                if (start < file.size && is_stop == 0) {
                    blob = cutFile(file);
                    uploadFile(blob, file);
                    blob_num += 1;
                } else {
                    //所有文件块上传完成
                }
            }, 1000);
        }
        xhr.send(form_data);
        //每次文件块上传后，清空上传信息
        form_data = "";
    }
}

class Upload
{
    
    private $filepath = './upload'; //上传目录
    
    private $tmpPath;
    
    private $blobNum;
    
    private $totalBlobNum;
    
    private $fileName;
    public function __construct($tmpPath, $blobNum,$totalBlobNum,$fileName, $filepath = ''){
        if (!empty($filepath)) {
            $this->filepath = $filepath;
        }
        $this->tmpPath = $tmpPath;
        $this->blobNum = $blobNum;
        $this->totalBlobNum = $totalBlobNum;
        $this->fileName = $fileName;
        //保存文件块
        $this->moveFile();
        //保存文件
        $this->fileMerge();
    }
    private function fileMerge(){
        //当文件块都上传后将文件块整合成文件
        if($this->blobNum == $this->totalBlobNum){
            for($i=1; $i<= $this->totalBlobNum; $i++){
                $blob = '';
                $blob = file_get_contents($this->filepath.'/'. $this->fileName.'__'.$i);
                file_put_contents($this->filepath.'/'. $this->fileName, $blob, FILE_APPEND );
                unset($blob);
            }
            //删除文件块
            $this->deleteFileBlob();
        }
    }
    //删除文件块
    private function deleteFileBlob(){
        for($i=1; $i<= $this->totalBlobNum; $i++){
            @unlink($this->filepath.'/'. $this->fileName.'__'.$i);
        }
    }
    private function moveFile(){
        $this->touchDir();
        $filename = $this->filepath.'/'. $this->fileName.'__'.$this->blobNum;
        //保存文件块
         move_uploaded_file($this->tmpPath,$filename);
    }
    //上传返回
    public function uploadReturn(){
        if($this->blobNum == $this->totalBlobNum){
            if(file_exists($this->filepath.'/'. $this->fileName)){
                return [
                    'code' => 2,
                    'message' => 'success',
                    'file_path' => 'http://'.$_SERVER['HTTP_HOST'].str_replace('.','',$this->filepath).'/'. $this->fileName,
                    'local_path' => str_replace('.','',$this->filepath).'/'. $this->fileName
                ];
            }
        }
        return [
            'code' => 1,
            'message' => 'waiting',
        ];
    }
    
    private function touchDir(){
        if(!file_exists($this->filepath)){
            return mkdir($this->filepath);
        }
    }
}

$tmpName = $_FILES['file']['tmp_name'];
$blobNum = $_POST['blob_num'];
$totalBlobNum = $_POST['total_blob_num'];
$fileName = $_POST['file_name'];
$upload = new Upload($tmpName, $blobNum, $totalBlobNum, $fileName);
$data = $upload->uploadReturn();
header('Content-type: application/json');
return json_encode($data);