Simple function to Http GET some data

Question

This is within a base class of a library, where several other classes inherit this one.

This seems like the simplest way of just getting some data, for now without timeout/errorhandling. This is supposed to get some data that will most ofthe time be converted to a small JSONObject.

Do you think I should put everything inside the try and use val? Any other suggestions? I'm basically just learning networking with android, only did it in C#.NET before.

protected fun sendGetRequest(url: URL): String {
    var urlConnection: HttpsURLConnection? = null
    var reader: InputStreamReader? = null
    var responseData = ""
    try {
        urlConnection = url.openConnection() as HttpsURLConnection

        reader = InputStreamReader(urlConnection.inputStream)
        responseData = reader.readText()
    }catch (e: Exception){
        this.messageHandler.handleMessage(e.message!!)
    }finally {
        reader?.close()
        urlConnection?.disconnect()
    }
    return responseData
}

Answer 1

The core of your code can be replaced by the following code:

url.openConnection()    //you can cast to fail if it isn't https
   .getInputStream()   //same as you
   .reader()          // same as wrapping it in inputStreamReader
   .use { it ->      // start lambda that handles the closing of the reader for you
      it.readText() // note, it's one parameter, so 'it ->' can be omitted
    }

The code above returns the text or throws the exception it got during execution, but always closes the reader, which in turn closes the connection.

The code above is almost the same as the code below btw:

url.readText()

If you want to remove all the variables, you should know that try catch can return a value:

val a = try{ 1 } catch(e: Exception) { 2 }