個人寫的php檔案上傳類，支援所有檔案上傳，對於圖片型別的檔案，提供產生縮圖方法，使用者可以自己進行配置。寫的很一般，沒有太多的測試，目前是沒什麼bug，就當提供學習和參考吧，程式碼：

<?php 
/**
 * +----------------------------------------------------------------------
 * | 檔案上傳類 Author Ftd Date: 15-03-18
 * | 如果上傳的檔案是圖片型別，提供生成縮圖方法
 * +----------------------------------------------------------------------
 * | 主要方法:upload();createThumb();
 * +----------------------------------------------------------------------
 * | 使用方法: 建立一個config = array();
 * | 提供引數：
 *   savePath       string              可選 檔案上傳路徑(若為空則為當前目錄下的upload資料夾) 
 *   thumbSavePath  string              可選 縮圖上傳路徑(若為空則代表和savePath相同的路徑)                
 *   ext            string(逗號分割)    可選 允許上傳的檔案型別(若為空則代表允許上傳任何型別的檔案)
 *   maxSize        int                 可選 允許上傳的最大值(若為空或為0則表示無限大)，此處和php.ini配置檔案無關
 *   fileName       string              可選 上傳檔名(若為空則使用原始檔名)
 *   needThumb      bool                可選 是否需要生成縮圖
 *   thumbWidth     int                 可選 縮圖寬度(若needThumb為true,則為必需)
 *   thumbHeight    int                 可選 縮圖高度(若needThumb為true,則為必需)
 *   needReplcePic  bool                可選 是否覆蓋原始檔(若為空則表示不覆蓋，若savePath不等於thumbSavePath,此引數失效)
 * +----------------------------------------------------------------------
 * | 舉例：
 * 
 *    $config = array(     //設定配置引數
 *       key => value
 *    )
 *    $obj = new UploadFile($config); //例項化物件
 *    $obj->upload($_FILES); //上傳檔案
 *    $obj->createThumb(); //生成縮圖
 * +----------------------------------------------------------------------
 * 
 */
 
 

class UploadFile 
{
    private $savePath ;  //上傳路徑
    private $ext = array(); //允許的字尾名，為空則表示不限制
    private $fileName ; //檔名
    private $fileTempName;//臨時檔名
    private $maxSize; //允許上傳最大值

    private $fileExt;//檔案字尾名
    private $fileSize;//檔案大小

    private $errorNum; //錯誤號
    private $errorMsg = ''; //錯誤資訊
 



    private $srcFile; //原始檔，用來生成縮圖
    private $thumbFile;//縮圖檔案
    private $thumbSavePath;//縮圖上傳路徑
    private $tempThumbImg;//臨時縮圖
    private $thumbWidth;  //縮圖寬度
    private $thumbHeight; //縮圖高度
    private $needThumb;      //是否需要縮圖
    private $needReplcePic;//是否覆蓋原始檔

    //預設配置
    private $acquiesce_config = array(
        'savePath'
 
 => './upload/',
        'thumbSavePath' => '',
        'ext' => '',
        'maxSize' => 0,
        'fileName' => '',
        'needThumb' => false,
        'thumbWidth' => 0,
        'thumbHeight' => 0,
        'needReplcePic' => false
    );

    /**
     * 構造方法
     * @param [array] $config
     */
    public function __construct($config = array())
    {   
        //如果引數為完全設定，將其設定為預設引數
        $config = array_merge($this->acquiesce_config,$config);
        $this->set_config($config);
    }

    /**
     * 設定上傳配置
     * @param [array] $config 
     */
    private function set_config($config)
    {   
        //分割字串得到檔案允許字尾名
        $ext_arr = explode(',', $config['ext']); 
        foreach ($ext_arr as $k => $v) {
            if($v != '')
            {
                $this->ext[] = $v;
            }
        }
        $this->set('savePath',$config['savePath']);
        $this->set('maxSize',$config['maxSize']);
        $this->set('fileName',$config['fileName']);

        $this->set('thumbHeight',$config['thumbHeight']);
        $this->set('thumbWidth',$config['thumbWidth']);
        $this->set('needThumb',$config['needThumb']);
        $this->set('needReplcePic',$config['needReplcePic']); 
        $this->thumbSavePath = $config['thumbSavePath'] == '' ? $this->savePath : $config['thumbSavePath'];
    }

    /**
     * [上傳檔案]
     * @param  [$file($_FILES)] 
     * @return [true|false]
     */
    public function upload($file)
    {
        if(!empty($file))
        {
            $fileName = $file['file']['name'];
            $fileSize = $file['file']['size'];
            $fileTempName = $file['file']['tmp_name'];
            $errorNum = $file['file']['error'];
            $ext = $this->get_fileExt($fileName);
            //檢查檔案引數
            $flag = $this->check_file_and_config($fileSize,$ext,$errorNum);
            if(!$flag)
            {
                return $this->get_errorMsg();
            }
            //設定檔名
            if($this->fileName != null)
            {
                $fileName = $this->fileName .'.'. $ext;
            }
            //設定檔案屬性
            $this->set_file($fileName,$fileTempName,$fileSize,$ext);
            //移動(上傳)檔案
            if(!$this->move_file())
            {
                return $this->get_errorMsg();
            }
            return 'success';
        }
    }


    /**
     * 得到檔案字尾名
     * @param  [string] $fileName [檔名]
     * @return [string]            [檔案字尾名]
     */
    private function get_fileExt($fileName)
    {   
        //得到檔案最後一個小數點，如果為false，說明檔案沒有後綴名
        $is_has_ext = strripos($fileName, '.');
        if(false == $is_has_ext)
        {
            return '';
        }
        $file_arr = explode('.', $fileName);
        $fileExt = strtolower($file_arr[count($file_arr) - 1]);
        return $fileExt;
    }

    /**
     * 檢查檔案的合法性
     * @param  [int]  $fileSize [檔案大小]
     * @param  [string]  $ext       [檔案字尾名]
     * @param  integer $errorNum [錯誤編號]
     * @return [true|false]            
     */
    private function check_file_and_config($fileSize,$ext,$errorNum = 0)
    {   

        $this->set('errorNum',$errorNum);

        if($errorNum != 0)
        {   
            return false;
        }
        if($this->savePath == '')
        {
            $this->set('errorNum',7);
            return false;
        }
        if(!in_array($ext, $this->ext) && count($this->ext) != 0)
        {
            $this->set('errorNum',5);
            return false;
        }
        if($fileSize > $this->maxSize && $this->maxSize != 0 && $this->maxSize != null)
        {
            $this->set('errorNum',6);
            return false;
        }

        return true;
    }

    /**
     * [設定成員變數]
     * @param [string] $fileName      [檔名]
     * @param [string] $fileTempName [臨時檔名]
     * @param [int] $fileSize      [檔案大小]
     * @param [string] $ext            [檔案字尾名]
     */
    private function set_file($fileName,$fileTempName,$fileSize,$ext)
    {
        $this->set('fileName',$fileName);
        $this->set('fileTempName',$fileTempName);
        $this->set('fileSize',$fileSize);
        $this->set('fileExt',$ext);
    }


    /**
     * [移動檔案]
     * @return [true|false] [成功返回true]
     */
    private function move_file()
    {   
        if($this->errorNum == 0)
        {   
            //建立檔案上傳目錄
            $this->create_folders($this->savePath);
            $move_file = $this->savePath .'/'. $this->fileName;
            if(move_uploaded_file($this->fileTempName, $move_file))
            {   
                //設定原始檔,用來建立縮圖
                $this->srcFile = $move_file;
                return true;
            }else
            {
                $this->set('errorNum',8);
                return false;
            }
        }else{
            return false;
        }
    }

    /**
     * [生成縮圖]
     * @return [string] 
     */
    public function createThumb()
    {   
        $flag = $this->check_thumb_param();
        if(!$flag)
        {   
            return $this->get_errorMsg();
        }
        $this->build_temp_thumb_img();//建立臨時圖片
        $this->build_thumb_path(); //建立縮圖路徑
        if(!$this->build_thumb())
        {
            return $this->get_errorMsg();
        }
        return 'create_thumb_success';
    }

    /**
     * [建立縮圖]
     * @return [true|false] 
     */
    private function build_thumb()
    {   
        //根據不同字尾名得到不同的方法
        $image_create_method = $this->get_create_img_function();
        //圖片實際寬度
        $real_width = imagesx($this->tempThumbImg);
        //圖片實際高度
        $real_height = imagesy($this->tempThumbImg);

        $thumb_img = imagecreatetruecolor($this->thumbWidth, $this->thumbHeight);
        $flag = imagecopyresampled($thumb_img, $this->tempThumbImg, 0, 0, 0, 0, $this->thumbWidth, $this->thumbHeight, $real_width, $real_height);
        $image_create_method($thumb_img,$this->thumbFile);
        if(!$flag)
        {
            $this->set('errorNum',13);
            return false;
        }
        return true;
    }

    /**
     * [得到imagejpeg|imagegif|imagepng]
     * @return [string] [方法名]
     */
    private function get_create_img_function()
    {
        if($this->fileExt == 'jpg')
        {
            $method = 'image'.'jpeg';
            return $method;
        }
        $method = 'image'.strtolower($this->fileExt);
        return $method;
    }

    /**
     * [檢查縮圖檔案引數]
     * @return [true|false] 
     */
    private function check_thumb_param()
    {   

        if($this->errorNum != 0)
        {
            return false;
        }
        if(empty($this->srcFile))
        {
            $this->set('errorNum',9);
            return false;
        }
        if($this->fileExt != 'jpg' && $this->fileExt != 'gif' && $this->fileExt != 'png')
        {
            $this->set('errorNum',10);
            return false;
        }
        if(!$this->needThumb)
        {
            $this->set('errorNum',11);
            return false;
        }
        if($this->thumbWidth == 0 || $this->thumbHeight == 0 || $this->thumbWidth == '' || $this->thumbHeight == '')
        {
            $this->set('errorNum',12);
            return false;
        }
        return true;
    }

    /**
     * [建立縮圖路徑]
     * @return [null] 
     */
    private function build_thumb_path()
    {   

        if($this->savePath == $this->thumbSavePath)
        {
            if($this->needReplcePic)
            {
                $this->thumbFile = $this->srcFile;
            }else
            {
                $this->thumbFile = $this->savePath.'/'.'thumb-'.$this->fileName;
            }

        }else{
            $this->create_folders($this->thumbSavePath);
            $this->thumbFile = $this->thumbSavePath.'/'.$this->fileName;
        }

    }

    /**
     * [建立臨時圖片]
     * @return [null]
     */
    private function build_temp_thumb_img()
    {
        switch ($this->fileExt) {
            case 'jpg':
                $this->set('tempThumbImg',imagecreatefromjpeg($this->srcFile));
                break;
            case 'gif':
                $this->set('tempThumbImg',imagecreatefromgif($this->srcFile));
                break;
            case 'png':
                $this->set('tempThumbImg',imagecreatefrompng($this->srcFile));
                break;  
            default:
                break;
        }
    }


    /**
     * 返回錯誤資訊
     * @return [string] 
     */
    private function get_errorMsg()
    {
        switch ($this->errorNum) {
            case 13:
                $this->errorMsg = "生成縮圖失敗";
                break;
            case 12:
                $this->errorMsg = "錯誤的縮率圖高度或寬度";
                break;
            case 11:
                $this->errorMsg = "若要生成縮圖，請在config中設定needThumb為true";
                break;
            case 10:
                $this->errorMsg = "該檔案不是圖片型別，不能產生縮圖";
                break;
            case 9:
                $this->errorMsg = "原始檔不存在，無法生成縮圖，請先上傳檔案";
                break;
            case 8:
                $this->errorMsg = "上傳失敗";
                break;
            case 7:
                $this->errorMsg = '請設定上傳路徑';
                break;
            case 6:
                $this->errorMsg = '上傳檔案大小超過maxSize最大值';
                break;
            case 5:
                $this->errorMsg = "錯誤的檔案型別";
                break;
            case 4:
                $this->errorMsg = '沒有檔案被上傳';
                break;
            case 3:
                $this->errorMsg = '檔案只有部分被上傳';
                break;
            case 2:
                $this->errorMsg = '上傳檔案的大小超過了 HTML 表單中 MAX_FILE_SIZE 選項指定的值';
                break;      
            case 1:
                $this->errorMsg = '上傳的檔案超過了 php.ini 中 upload_max_filesize 選項限制的值';
                break;
            default:
                break;
        }

        return $this->errorMsg;
    }

    /**
     * set方法(過濾成員引數)
     * @param  $key   
     * @param  $value 
     */
    public function set($key,$value)
    {   
        //檢驗key是否是本類的成員屬性
        if(array_key_exists($key, get_class_vars(get_class($this))))
        {
            $this->setProperty($key,$value);
        }
    }

    /**
     * [設定property]
     * @param [property] $key  
     * @param [property] $value 
     */
    private function setProperty($key,$value)
    {   
        if($key == 'ext')
        {
            $ext_arr = explode(',', $value);
            foreach ($ext_arr as $k => $v) {
                if($v != '')
                {
                    $this->ext[] = $v;
                }
            }
            return;
        }
        $this->$key = $value;
    }

    /**
     * 遞迴建立資料夾
     * @param  [string] $dir [目錄]
     * @return [true|false]     
     */
    private function create_folders($dir)
    {
        return is_dir($dir) or ($this->create_folders(dirname($dir)) and mkdir($dir, 0777));
    }
}

 ?>

如有bug或建議，歡迎指正