Scala example source code file (Socket.scala)

This example Scala source code file (Socket.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

box, box, bufferedreader, int, int, io, jsocket, net, network, printwriter, serversocket, socket, socket, t, t, t1, u

The Scala Socket.scala source code

/* NSC -- new Scala compiler
 * Copyright 2005-2011 LAMP/EPFL
 * @author  Paul Phillips
 */

package scala.tools.nsc
package io

import java.io.{ IOException, InputStreamReader, BufferedReader, PrintWriter, Closeable }
import java.io.{ BufferedOutputStream, BufferedReader }
import java.net.{ ServerSocket, SocketException, SocketTimeoutException, InetAddress, Socket => JSocket }
import scala.sys.SystemProperties._
import scala.io.Codec

/** A skeletal only-as-much-as-I-need Socket wrapper.
 */
object Socket {  
  def preferringIPv4[T](body: => T): T = exclusively {
    val saved = preferIPv4Stack.value
    try   { preferIPv4Stack.enable() ; body }
    finally preferIPv4Stack setValue saved
  }

  class Box[+T](f: () => T) {
    private def handlerFn[U](f: Throwable => U): PartialFunction[Throwable, U] = {
      case x @ (_: IOException | _: SecurityException)  => f(x)
    }
    private val optHandler = handlerFn[Option[T]](_ => None)
    private val eitherHandler = handlerFn[Either[Throwable, T]](x => Left(x))
    
    def getOrElse[T1 >: T](alt: T1): T1 = opt getOrElse alt
    def either: Either[Throwable, T]    = try Right(f()) catch eitherHandler
    def opt: Option[T]                  = try Some(f()) catch optHandler
  }

  def newIPv4Server(port: Int = 0)        = new Box(() => preferringIPv4(new ServerSocket(0)))
  def newServer(port: Int = 0)            = new Box(() => new ServerSocket(0))
  def localhost(port: Int)                = apply(InetAddress.getLocalHost(), port)
  def apply(host: InetAddress, port: Int) = new Box(() => new Socket(new JSocket(host, port)))
  def apply(host: String, port: Int)      = new Box(() => new Socket(new JSocket(host, port)))
}

class Socket(jsocket: JSocket) extends Streamable.Bytes with Closeable {
  def inputStream()  = jsocket.getInputStream()
  def outputStream() = jsocket.getOutputStream()
  def getPort()      = jsocket.getPort()
  def close()        = jsocket.close()
  
  def printWriter()                         = new PrintWriter(outputStream(), true)
  def bufferedReader(implicit codec: Codec) = new BufferedReader(new InputStreamReader(inputStream()))
  def bufferedOutput(size: Int)             = new BufferedOutputStream(outputStream(), size)
  
  /** Creates an InputStream and applies the closure, automatically closing it on completion.
   */
  def applyReaderAndWriter[T](f: (BufferedReader, PrintWriter) => T): T = {
    val out = printWriter()
    val in  = bufferedReader
    
    try f(in, out)
    finally {
      in.close()
      out.close()
    }
  }  
}