php常用文件上传类

/**
 * flie class
 * (jpg,gif,png)
 */
class Upload {
 var $_file;
 var $_fileType;
 var $target = 'upload/';
 
 /**
  * construct for this class
  *
  * @param string $name
  * @return Upload
  */
 function Upload($name) {
  if(isset($_FILES[$name])) {
   $this->_file = &$_FILES[$name];
   $this->_parseUploadFile();
  } else {
   die('No file upload.');
  }
 }
 
 /**
  * set upload target path
  *
  * @param string $path
  * @return boolean
  */
 function setTarget($path = 'upload/') {
  if(is_dir($path)) {
   $this->target = rtrim($path,'/').'/';
   return true;
  } else {
   return false;
  }
 }
 
 /**
  * get the type of the file
  *
  */
 function _parseUploadFile() {
  $type = $this->_file['type'];
  if(isset($type) && $type != '') {
   switch ($type) {
    case 'image/gif':
     $this->_fileType = 'gif';
     break;
    case 'image/png':
     $this->_fileType = 'png';
     break;
    case 'image/jpeg':
     $this->_fileType = 'jpg';
     break;
    case 'image/pjpeg':
     $this->_fileType = 'jpg';
     break;
    default:
     $this->_fileType = 'unknow';
     break;
   }
  } else {
   $filename = $this->_file['name'];
   $filename = explode('.',$filename);
   $filename = strtoupper($filename[sizeof($filename) - 1]);
   switch ($filename) {
    case 'PNG':
     $this->_fileType = 'png';
     break;
    case 'JPEG':
     $this->_fileType = 'jpg';
     break;
    case 'JPG':
     $this->_fileType = 'jpg';
     break;
    case 'GIF':
     $this->_fileType = 'gif';
     break;
    default:
     $this->_fileType = 'unknow';
     break; 
   }
   unset($filename);
  }
  unset($type);
 }
 
 /**
  * upload file
  *
  * @return array
  */
 function load() {
  if($this->_fileType == 'unknow') {
   die('Can not upload this file,because the type is not allow.');
  }
  if(file_exists($this->_file['tmp_name']) && is_uploaded_file($this->_file['tmp_name'])) {
   $new_file_name = $this->target.time().'.'.$this->_fileType;
   move_uploaded_file($this->_file['tmp_name'],$new_file_name);
   
   return array('name'=>$new_file_name,'size'=>$this->_file['size'],'type'=>$this->_fileType);
  } else {
   return false;
  }
 }
}
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