Groovy 从 URL 下载图像

我想知道从该 RUL 下载图像的正确方法是什么：http://www.hidemyass.com/proxy-list/img/port/7018246/1 http://www.hidemyass.com/proxy-list/img/port/7018246/1

我尝试下载它的方式导致文件格式未知。我测试的当前代码片段是：

public void download(def address) {

    def file = new FileOutputStream(address.tokenize("/")[-1])
    def out = new BufferedOutputStream(file)
    out << new URL(address).openStream()
    out.close()
}

这有效吗？我相信应该：

public void download(def address) {
  new File("${address.tokenize('/')[-1]}.png").withOutputStream { out ->
    out << new URL(address).openStream()
  }
}