Multithreaded Item Price Checking server in scala - multithreading

Question

I am trying to implement a multithreaded item price checking server, where I have two classes : A Server and A Client. My Server should also have access to a file where it will hold items with respective prices, and my client should be able to ask for an item "ex. Coffee" and get its price from server "ex. $2.00". Now I don't know how to make a file and extract required information, so need help.
Here is my Server Code:
import java.io.{DataInputStream, DataOutputStream}
import java.net.ServerSocket
import scala.concurrent.ExecutionContext.Implicits.global
import scala.concurrent.Future
object server extends App {
// Register service on port 9000
val server = new ServerSocket(9000)
while(true) {
// Register service on port 1234
val socket = server.accept()
Future {
//store local socket references for processing
val client = socket
try {
// Get a communication stream associated with the socket
val is = new DataInputStream(client.getInputStream())
// Get a communication stream associated with the socket
val os = new DataOutputStream(client.getOutputStream())
// Read from input stream
var line: String = is.readLine()
// sending string
os.writeBytes("$2.00\n")
println(line)
} catch {
case e: Exception => e.printStackTrace
} finally {
// Close the connection, but not the server socket
client.close()
}
}
}
}
Here is my Client Code:
import java.io.{DataInputStream, DataOutputStream}
import java.net.Socket
object client extends App {
var client: Option[Socket] = None
try {
//Open your connection to a server, at port 9000
client = Some(new Socket("127.0.0.1", 9000))
// Get an input file handle from the socket
val is = new DataInputStream(client.get.getInputStream)
val os = new DataOutputStream(client.get.getOutputStream)
// write to server a string
//os.writeBytes("Hello from client\n")
os.writeBytes("Coffee\n")
//read from server a string
var line: String = is.readLine()
//printing output
println(line)
}
catch {
case e: Exception => e.printStackTrace()
}
finally {
client foreach (_.close())
}
}