Groovy download image from URL

Question

I am wondering what the proper way to go about downloading the image from this RUL would be: http://www.hidemyass.com/proxy-list/img/port/7018246/1

The way I tried downloading it, leaves the file in an unknown format. Current code snippet I tested out is:

public void download(def address) {

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

Answer 1

You can get image type from their content type - URLConnection.getContentType() or from byte array:

content="http://www.google.ru/images/logo.png".toURL().getBytes()
ext=URLConnection.guessContentTypeFromStream(new ByteArrayInputStream(content)).replaceFirst("^image/","")
new File("logo."+ext).setBytes(content)

Answer 2

Thanks Tim, I also found your answer very helpful, just small note: Looks like you haven't closed URL stream. I'm just starting with Groovy, and I've heard that it close steams when exit from closure so we can change code like that:

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

Answer 3

Does this work? I believe it should:

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