Question

I’m trying to generalize the following code:

def fetchUrl = {
  try {
    val lineList = Source.fromURL(url).getLines.toList
    process(lineList)
  }
  catch {
    case ex: java.net.UnknownHostException => ex.printStackTrace()
  }
}

I want to be able to fetch URL’s (fromURL) and files (fromFile) with the same method. Is it possible to generalize this code to archive this?

I figured I could use pattern matching for this but I don’t know how.

def fetchSource(src: Source, str: String) = src match {
  case ??? => Source.fromURL(url).getLines.toList
  case ??? => Source.fromFile(str).getLines.toList
}

Is there a way to get this right?

Thanks in advance.

Answer 1

The simplest solution is to have one method that will fetch a given Source, and two wrapper methods that build Source from File or URL.

def fetchSource(source: io.Source) =
  try {
    val lineList = source.getLines.toList
    process(lineList)
  } catch {
    case ex: java.net.UnknownHostException => ex.printStackTrace()
  }

def fetchFile(file: java.io.File) = fetchSource(io.Source.fromFile(file))

def fetchUrl(url: java.net.URL) = fetchSource(io.Source.fromURL(url))