how to use socket IO in kotlin? - socket.io

Question

I want to initialize socket IO in my kotlin app.
my problem is here :
private var mSocket: Socket? = null
{
try {
mSocket = IO.socket("http://chat.socket.io")
} catch (URISyntaxException e) {
}
}
import com.github.nkzawa.socketio.client.IO
cant recognize

Answer 1

I searched for this some more and found this solution:
You connect your ws like this:
val opts = IO.Options()
opts.path = "/path/to/ws"
opts.transports = arrayOf(WebSocket.NAME) // Set the transfer to 'websocket' instead of 'polling'
val webSocket = IO.socket("http(s)://your.ip.here", opts)
webSocket.connect()
.on(Socket.EVENT_CONNECT) {
// Do your stuff here
}
.on("foo") { parameters -> // do something on recieving a 'foo' event
// 'parameters' is an Array of all parameters you sent
// Do your stuff here
}
If you want to emit an event, you'll call:
webSocket.emit("foo", "bar") // Emits a 'foo' event with 'bar' as a parameter
You will need to use
import com.github.nkzawa.socketio.client.IO;
import com.github.nkzawa.socketio.client.Socket;
so be sure to add the corresponding libraries to your build.gradle
dependencies {
...
implementation 'com.github.nkzawa:socket.io-client:0.6.0'
}

Answer 2

first import this
import com.github.nkzawa.socketio.client.IO;
import com.github.nkzawa.socketio.client.Socket;
and then initialize this one
val socket = IO.socket("http://localhost:4000/")
socket.on(Socket.EVENT_CONNECT, Emitter.Listener {
socket.emit("messages", "hi")
});
socket.connect()

Answer 3

It's a static block in java But we can't wirte same as in Kotlin.
We can use its like a companion object.
companion object{
private var mSocket: Socket?=null
init {
try {
mSocket = IO.socket(Constants.Chat_URl)
}
catch (e: Exception){
throw RuntimeException(e)
}
}
}

Answer 4

In Kotlin you can make a Socket Client like the following. All the Exceptions are handled here too.
fun pingYourTCPServerWith(message: String): String{
try {
val socket = Socket("<YOUR IP ADDRESS>", <YOUR PORT HERE>)
socket.use {
var responseString : String? = null
it.getOutputStream().write(message.toByteArray())
val bufferReader = BufferedReader(InputStreamReader(it.inputStream))
while (true) {
val line = bufferReader.readLine() ?: break
responseString += line
if (line == "exit") break
}
println("Received: $responseString")
bufferReader.close()
it.close()
return responseString!!
}
}catch (he: UnknownHostException){
val exceptionString = "An exception occurred:\n ${he.printStackTrace()}"
return exceptionString
}catch (ioe: IOException){
val exceptionString = "An exception occurred:\n ${ioe.printStackTrace()}"
return exceptionString
} catch (ce: ConnectException){
val exceptionString = "An exception occurred:\n ${ce.printStackTrace()}"
return exceptionString
}catch (se: SocketException){
val exceptionString = "An exception occurred:\n ${se.printStackTrace()}"
return exceptionString
}
}

Answer 5

The right syntax is below for anyone who is interested in the future
private lateinit var mSocket:Socket
fun socket(){
try {
mSocket=IO.socket("http://host:port")
}
catch(e: URISyntaxException){
println("Exception"+e)
}
}