protected $file_size = 1024000;

protected $file_size = 5120000; //5M 用户上传
//检测文件是否为空
public function check_file($get_file)
{
if (empty($get_file))
{
$type = "check_file";
$arr = array('error'=>'empty_name','type'=>$type);
echo json_encode($arr);
exit();
}
return true;
}

//检测文件类型
public function check_type($get_type)
{
if (( $get_type == ".docx" ) || ( $get_type == ".doc" )) {

$types = $get_type;

}else{
$type = "check_type";
$arr = array('error'=>'format','type'=>$type);
echo json_encode($arr);
exit();

}
return true;
}

//检测文件大小
public function check_size($get_file)
{
if ( $get_file != "" ) {
if ( $get_file > $this->file_size ) {
$arr = array('error'=>'large');
echo json_encode($arr);
exit();
}
}else{
return false;
exit();
}
return true;
}

//文件保存
public function save_file($file_type,$file_tmp_name)
{
$rand = rand(1000,9999);
$pics = date("YmdHis") . $rand . $file_type;
$path = $this->file_path."/".$pics;
$result = move_uploaded_file($file_tmp_name,$path);
if($result){
return $pics;
}else{
return false;
exit();
}

return $pics;

}

}
PHP文件上传处理
<?php
include("upload.class.php");
$up_obj = new upload();

$get_fileName = $_FILES['mypic']['name'];
$get_fileSize = $_FILES['mypic']['size'];
$get_TmpFiles = $_FILES['mypic']['tmp_name'];

$get_fileType = strstr($get_fileName,'.');

$check_result = $up_obj->check_file($get_fileName);

if($check_result){

//检查文件类型
$result_type = $up_obj->check_type($get_fileType);

//检查文件大小
if($result_type){

$result_size = $up_obj->check_size($get_fileSize);

if($result_size){
  //文件上传保存  
  $pics = $up_obj->save_file($get_fileType,$get_TmpFiles);   
  $size = round($get_fileSize/1024,2);
      $arr = array(
        'name' => $get_fileName,'pic' => $pics,'size'=> $size,'error' => 2
     );

   //检查文件上传状态
   if($pics){
     echo json_encode($arr);
     /*
     执行上传完成逻辑.....
     */
  }   
}

}

}