How to download a file? - Groovy

I need to download a file (this one for example: https://www.betaseries.com/srt/391160) so I have found different methods on the web:

def download(String remoteUrl, String localUrl)
{
    def file = new FileOutputStream(localUrl)
    def out = new BufferedOutputStream(file)
    out << new URL(remoteUrl).openStream()
    out.close()
}

or

def download(String remoteUrl, String localUrl) {
  new File("$localUrl").withOutputStream { out ->
      new URL(remoteUrl).withInputStream { from ->  out << from; }
  }
}

I see that the file is created but the file size is always equal to 1KB how can I fx it?

Thank in advance,

Benjamin