HTTP Request in Kotlin

Question

I\'m completely new to Kotlin. I want to do a login validation using POST method and to get some information using GET method. I\'ve URL, server Username and Password alread

Answer 1

Without adding additional dependencies, this works. You don't need Volley for this. This works using the current version of Kotlin as of Dec 2018: Kotlin 1.3.10

If using Android Studio, you'll need to add this declaration in your AndroidManifest.xml:

You should manually declare imports here. The auto-import tool caused me many conflicts.:

import android.os.AsyncTask
import java.io.BufferedReader
import java.io.InputStreamReader
import java.io.OutputStream
import java.io.OutputStreamWriter
import java.net.URL
import java.net.URLEncoder
import javax.net.ssl.HttpsURLConnection

You can't perform network requests on a background thread. You must subclass AsyncTask.

To call the method:

NetworkTask().execute(requestURL, queryString)

Declaration:

private class NetworkTask : AsyncTask() {
    override fun doInBackground(vararg parts: String): Long? {
        val requestURL = parts.first()
        val queryString = parts.last()

        // Set up request
        val connection: HttpsURLConnection = URL(requestURL).openConnection() as HttpsURLConnection
        // Default is GET so you must override this for post
        connection.requestMethod = "POST"
        // To send a post body, output must be true
        connection.doOutput = true
        // Create the stream
        val outputStream: OutputStream = connection.outputStream
        // Create a writer container to pass the output over the stream
        val outputWriter = OutputStreamWriter(outputStream)
        // Add the string to the writer container
        outputWriter.write(queryString)
        // Send the data
        outputWriter.flush()

        // Create an input stream to read the response
        val inputStream = BufferedReader(InputStreamReader(connection.inputStream)).use {
            // Container for input stream data
            val response = StringBuffer()
            var inputLine = it.readLine()
            // Add each line to the response container
            while (inputLine != null) {
                response.append(inputLine)
                inputLine = it.readLine()
            }
            it.close()
            // TODO: Add main thread callback to parse response
            println(">>>> Response: $response")
        }
        connection.disconnect()

        return 0
    }

    protected fun onProgressUpdate(vararg progress: Int) {
    }

    override fun onPostExecute(result: Long?) {
    }
}