PHP实现下载远程图片保存到本地的方法

1.使用 curl

比如我们有下面这两张图片：

		$images = [ 
	
		  'https://dn-laravist.qbox.me/2015-09-22_00-17-06j.png', 
	
		  'https://dn-laravist.qbox.me/2015-09-23_00-58-03j.png' 
	
		];

第一步，我们可以直接来使用最简单的代码实现：

function download($url, $path = 'images/')

{

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $url);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);

$file = curl_exec($ch);

curl_close($ch);

$filename = pathinfo($url, PATHINFO_BASENAME);

$resource = fopen($path . $filename, 'a');

fwrite($resource, $file);

fclose($resource);

}

那在下载远程图片的时候就可以这样：

foreach ( $images as $url ) { download($url); }

2.封装一个类

缕清思路之后，我们可以将这个基本的功能封装到一个类中：

class Spider {



  public function downloadImage($url, $path = 'images/')

  {

    $ch = curl_init();

    curl_setopt($ch, CURLOPT_URL, $url);

    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);

    $file = curl_exec($ch);

    curl_close($ch);

    $filename = pathinfo($url, PATHINFO_BASENAME);

    $resource = fopen($path . $filename, 'a');

    fwrite($resource, $file);

    fclose($resource);

  }

}  

在者，我们还可以这样稍微优化一下：

public function downloadImage($url, $path='images/')

  {

    $ch = curl_init();

    curl_setopt($ch, CURLOPT_URL, $url);

    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);

    $file = curl_exec($ch);

    curl_close($ch);



    $this->saveAsImage($url, $file, $path);

  }



  private function saveAsImage($url, $file, $path)

  {

    $filename = pathinfo($url, PATHINFO_BASENAME);

    $resource = fopen($path . $filename, 'a');

    fwrite($resource, $file);

    fclose($resource);

  }