PHP文件上傳類

<?php

class Upload {
    private $error;
    private $destination;
    private $fileInfo;
    private $uploadDir;
    private $maxFileSize;
    private $allowExt;
    private $checkImage;

    function __construct($fileInfo, $uploadDir = './uploads', $maxFileSize = 1024 * 1024 * 1,
                         $allowExt = array('jpg', 'gif', 'png', 'bmp', 'jpeg'),
                         $checkImage = true, $allowMime = array('image/gif', 'image/jpeg', 'image/png')) {
        $this->fileInfo = $fileInfo;
        $this->uploadDir = $uploadDir;
        $this->maxFileSize = $maxFileSize;
        $this->allowExt = $allowExt;
        $this->checkImage = $checkImage;
        $this->allowMime = $allowMime;
    }

    /***
     * 處理上傳文件
     * @return string
     */
    public function uploadFile() {
        if (!$this->fileInfo) {
            $this->error = '文件信息不存在';
            return $this->error;
        }

        if ($this->checkError() && $this->checkImageType() && $this->checkMaxFileSize() && $this->checkAllowExt()
            && $this->checkPostUpload() && $this->checkMime()
        ) {
            //判斷文件夾是否存在
            $this->checkUploadDir();
            //生成惟一文件名
            $destination = $this->uploadDir . '/' . $this->buildUniqueId() . '.' . $this->getExt();
            if (@move_uploaded_file($this->fileInfo['tmp_name'], $destination)) {
                $this->destination = $destination;
                return $this->destination;
            } else {
                $this->error = '移動上傳文件失敗';
            }
            return $this->error;
        }

        return $this->error;
    }

    private function checkError() {
        if ($this->fileInfo['error'] == UPLOAD_ERR_OK) {
            return true;
        }
        $this->error = '上傳出現錯誤,錯誤代碼:' . $this->fileInfo['error'];
        return false;
    }

    private function buildUniqueId() {
        return md5(uniqid(microtime(true), true));
    }

    private function checkUploadDir() {
        if (!file_exists($this->uploadDir)) {
            mkdir($this->uploadDir, 0777, true);
            chmod($this->uploadDir, 0777);
        }
    }

    private function checkAllowExt() {
        if (in_array($this->getExt(), $this->allowExt)) {
            return true;
        }
        $this->error = '該類型的文件不能上傳';
        return false;
    }

    private function checkMaxFileSize() {
        if ($this->maxFileSize > $this->fileInfo['size']) {
            return true;
        }
        $this->error = '上傳文件的大小已超過限額';
        return false;
    }

    private function checkImageType() {
        if ($this->checkImage) {
            if ($this->checkAllowExt() && getimagesize($this->fileInfo['tmp_name'])) {
                return true;
            }
            $this->error = '上傳的不是圖片';
            return false;
        }
        return true;
    }

    private function checkPostUpload() {
        if (is_uploaded_file($this->fileInfo['tmp_name'])) {
            return true;
        }
        $this->error = '不是Post上傳的文件';
        return false;
    }

    private function checkMime() {
        if (in_array($this->getMime(), $this->allowMime)) {
            return true;
        }
        $this->error = 'Mime類型不正確';
        return false;
    }

    private function getMime() {
        if ($imageInfo = getimagesize($this->fileInfo['tmp_name'])) {
            return $imageInfo['mime'];
        }
        return false;
    }

    private function getExt() {
        return strtolower(pathinfo($this->fileInfo['name'], PATHINFO_EXTENSION));
    }
}