public function download() {
    $http = new \Org\Net\Http();
    $url_pref = "http://www.dzkbw.com/books/rjb/dili/xc7s/";
    $localUrl = "Public/bookcover/";
    $reg="|showImg\('(.+)'\);|";
    $i=1;
    
    do {
      $filename = substr("000".$i,-3).".htm";
      $ch = curl_init();
      curl_setopt($ch, CURLOPT_URL, $url_pref.$filename);
      curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
      curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
      curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
      $html = curl_exec($ch);
      curl_close($ch);
      
      $result = preg_match_all($reg,$html,$out, PREG_PATTERN_ORDER);
      if($result==1) {
        $picUrl = $out[1][0];
        $picFilename = substr("000".$i,-3).".jpg";
        $http->curlDownload($picUrl, $localUrl.$picFilename);
      }
      $i = $i+1;
    } while ($result==1);

    echo "下载完成";
  }