<?php

class UploadFile
{
 const UPLOAD_ERROR = [
  UPLOAD_ERR_INI_SIZE => '文件大小超出php.ini当中的upload_max_filesizes的大小',
  UPLOAD_ERR_FORM_SIZE => '超出表单当中的MAX_FILE_SIZE的大小',
  UPLOAD_ERR_PARTIAL => '部分文件被上传',
  UPLOAD_ERR_NO_FILE => '没有文件被上传',
  UPLOAD_ERR_NO_TMP_DIR => '临时目录不存在',
  UPLOAD_ERR_CANT_WRITE => '磁盘写入失败',
  UPLOAD_ERR_EXTENSION => '文件上传被PHP扩展阻止',
 ];
 
 protected $field_name;
 
 protected $destination_dir;
 
 protected $allow_mime;
 
 protected $allow_ext;
 
 protected $allow_size;
 
 protected $file_org_name;
 
 protected $file_type;
 
 protected $file_tmp_name;
 
 protected $file_error;
 
 protected $file_size;
 
 protected $errors = [];
 
 protected $extension;
 
 protected $file_new_name;
 
 public function __construct($keyName,$destinationDir = './upload',$allowMime = ['image/jpeg','image/png','image/gif'],$allowExt = ['jpeg','jpg','png','gif'],$allowSize = 2*1024*1024){
  $this->filed_name = $keyName;
  $this->destination_dir = $destinationDir;
  $this->allow_mime = $allowMime;
  $this->allow_ext = $allowExt;
  $this->allow_size = $allowSize;
 }
  
 public function setDestinationDir($destinationDir){
  $this->destination_dir = $destinationDir;
 }
 
 public function setAllowMime($allowMime){
  $this->allow_mime = $allowMime;
 }
 
 public function setAllowExt($allowExt){
  $this->allow_ext = $allowExt;
 }
 
  public function setAllowSize($allowSize){
   $this->allow_size = $allowSize;
  }
  public function upload(){
   
  //接受$_FILES参数
  $this->setFileInfo();
  
  //检查错误
  $this->checkError();
  
  //检查MIME类型
  $this->checkMime();
  
  //检查扩展名
  $this->checkExt();
  
  //检查文件大小
  $this->checkSize();
  
  //生成新的文件名称
  $this->generateNewName();
  
  //移动文件
  $this->moveFile();
  
  if(count($this->getError())>0){
   return false;

  }
  return true;
  }
 
  public function getError(){
   
  return $this->errors;
  }
 
  protected function setFileInfo(){
   
  $this->file_org_name = $_FILES[$this->field_name]['name'];
  
  $this->file_type = $_FILES[$this->field_name]['type'];
  
  $this->file_tmp_name = $_FILES[$this->field_name]['tmp_name'];
  
  $this->file_error = $_FILES[$this->field_name]['error'];
  
  $this->file_size = $_FILES[$this->field_name]['size'];
  
  }
 
  protected function setError($error){
   
  $this->errors[] = $error;
  }
 
  protected function checkError(){
   
  if($this->file_error>UPLOAD_ERR_OK){
   switch($this->file_error){
    case UPLOAD_ERR_INI_SIZE:
    case UPLOAD_ERR_FORM_SIZE:
    case UPLOAD_ERR_PARTIAL:
    case UPLOAD_ERR_NO_FILE:
    case UPLOAD_ERR_NO_TMP_DIR:
    case UPLOAD_ERR_CANT_WRITE:
    case UPLOAD_ERR_EXTENSION:
     $this->setError(self::UPLOAD_ERROR[$this->file_error]);
     return FALSE;
   }
  }
  return TRUE;
  }
 
  protected function checkMime(){
   
  if(!in_array($this->file_type,$this->allow_mime)){
   $this->setError( '文件类型'.$this->file_type.'不被允许');
   return false;
  }
  return true;
  
  }
 
  protected function checkExt(){
 
   $this->extension = pathinfo($this->file_org_name,PATHINFO_EXTENSION);
  if(!in_array($this->extension, $this->allow_ext)){
   $this->setError('文件扩展名'.$this->extension.'不被允许');
   return false;
  } 
  return true;
  } 
 
  protected function checkSize(){
   
   if($this->file_size > $this->allow_size){
   $this->setError('文件大小'.$this->file_size.'超出限定大小'.$this->allow_size.'!');
   return false;
  }
  return true;
  }
 
  protected function generateNewName(){
   
  $this->file_new_name = uniqid().'.'.$this->extension;
  }
 
  protected function moveFile(){
   
  if(!file_exists($this->destination_dir)){
   mkdir($this->destination_dir,0777,true);
  }
  $newName = $this->destination_dir.'/'.$this->file_new_name;
  if(is_uploaded_file($this->file_tmp_name) && move_uploaded_file($this->file_tmp_name, $newName)){
   return true;
  }
  $this->setError('上传失败');
   return FALSE;
  }
 
  public function getFileName(){
   
  return $this->file_new_name;
  }
 
  public function getDestinationDir(){
   
  return $this->destination_dir;
  }
 
  public function getExtension(){
   
  return $this->destination_dir;
  }
 
  public function getFileSize(){
   
  return $this->file_size;
  }
 
}

?>

<?php

require('UploadFile.php');

$upload = new UploadFile('file',['image/jpeg','image/png','image/gif'],['jpeg','jpg','png','gif'],2*1024*1024);
$upload->setDestinationDir('./upload');
$upload->setAllowMime(['image/jpeg','image/png','image/gif']);
$upload->setAllowExt(['jpeg','jpg','png','gif']);
$upload->setAllowSize(2*1024*1024);
if($upload->upload()){
 echo $newName = $upload->getFileName().'<br>';
 echo $destDir = $upload->getDestinationDir().'<br>';
 echo $ext = $upload->getExtension().'<br>';
 echo $size = $upload->getFileSize().'<br>';
}else{
 var_dump($upload->getErrors());
}
?>