Codeigniter实现多文件上传并创建多个缩略图

该程序可以实现:
1.同时上传5张图片
2.同时生成两种尺寸的缩略图
3.保存到mysql

controllers：upload.php文件：

代码如下:<?php
class Upload extends Controller {
  function go() {
    if(isset($_POST['go'])) {
      //初始化
      $config['upload_path'] = 'album/source';
      $config['allowed_types'] = 'gif|jpg|png|bmp|jpeg';
      $config['encrypt_name'] = TRUE;
      $config['remove_spaces'] = TRUE;
      $config['max_size']  = '0';
      $config['max_width']  = '0';
      $config['max_height']  = '0';

      $this->load->library('upload', $config);

      //170*170图片
      $configThumb = array();
      $configThumb['image_library'] = 'gd2';
      $configThumb['source_image'] = '';
      $configThumb['create_thumb'] = TRUE;
      $configThumb['maintain_ratio'] = TRUE; //保持图片比例
      $configThumb['new_image'] = 'album/thumb';
      $configThumb['width'] = 170;
      $configThumb['height'] = 170;
      //600*600图片
      $configLarge = array();
      $configLarge['image_library'] = 'gd2';
      $configLarge['source_image'] = '';
      $configLarge['create_thumb'] = TRUE;
      $configLarge['maintain_ratio'] = TRUE; //保持图片比例
      $configLarge['new_image'] = 'album/large';
      $configLarge['width'] = 600;
      $configLarge['height'] = 600;

      $this->load->library('image_lib');

      for($i = 1; $i < 6; $i++) {
        $upload = $this->upload->do_upload('image'.$i);      
        if($upload === FALSE) continue;
        $data = $this->upload->data();//返回上传文件的所有相关信息的数组
        $uid = $this->session->userdata('uid');
        $uploadedFiles[$i] = $data;

        if($data['is_image'] == 1) {
          //初始化170*170 
          $configThumb['source_image'] = $data['full_path']; //文件路径带文件名