Scala example source code file (basic.scala)

This example Scala source code file (basic.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

bar, bufferedreader, bufferedreader, client, client, clientthread, foo, int, list, list, runnable, serverthread, string, string

The Scala basic.scala source code

/*
 *  @author Stephane Micheloud
 */

object Test {

  val name = "basic"
  val host = "127.0.0.1"
  val port = 8889

  def main(args: Array[String]) {
    setenv()
    println("Server.main "+port)
    server.start()
    println("Client.main "+host+" "+port)
    client.start()
    server.terminate()
  }

  private var server = new ServerThread(port)
  private var client = new ClientThread(host, port)

  private class ServerThread(port: Int) extends Runnable {
    private var th = new Thread(this)
    def start() { th.start(); Thread.sleep(1000) }
    def run() { Server.main(Array(port.toString)) }
    def terminate() { Server.terminate(); sys.exit(0) }
  }

  private class ClientThread(host: String, port: Int) extends Runnable {
    private var th = new Thread(this)
    def start() { th.start(); th.join() }
    def run() { Client.main(Array(host, port.toString)) }
  }

  private def setenv() {
    import Env._

    // Java properties for server & client
    System.setProperty("scala.remoting.logLevel", logLevel)
    System.setProperty("java.security.manager", "")
    System.setProperty("java.security.policy", policyFile)
    // Java properties for server only
    System.setProperty("java.rmi.server.codebase", deployUrl)
    System.setProperty("java.rmi.server.hostname", host)
    System.setProperty("java.rmi.server.useCodebaseOnly", "true")

    // application-secific classes to be deployed and accessed via URL
    // (i.e. detached closure, proxy interfaces and proxy stubs)
    val classNames = List(
      "Bar$proxy",
      "Bar$proxyImpl_Stub",
      "Client$$anonfun$main$1$detach",
      "Client$proxy",
      "Client$proxyImpl_Stub",
      "Foo$proxy",
      "Foo$proxyImpl_Stub")

    val proxyImplNames =
      for (n <- classNames; i = n lastIndexOf "_Stub"; if i > 0)
      yield n.substring(0, i)

    generatePolicyFile()
    generateRmiStubs(proxyImplNames)
    generateJarFile(classNames)
  }
}

object Env {
  import java.io._, java.util.jar._

  val actors_logLevel = "0"
                   // = "3" // info+warning+error
  val logLevel = "silent"
            // = "info"     // debug user code only
            // = "info,lib" // debug user & library code

  // we assume an Apache server is running locally for deployment
  private val sep = File.separator
  val docPath = System.getProperty("user.home")+sep+"public_html"
  val docRoot = "http://127.0.0.1/~"+System.getProperty("user.name")

  private val policyTmpl =
    System.getProperty("partest.cwd")+sep+Test.name+sep+"java.policy"
  val outPath = System.getProperty("partest.output")
  val libPath = System.getProperty("partest.lib")
  val policyFile = outPath+sep+"java.policy"
  val codebaseDir = outPath+sep+"-"

  assert((new File(docPath)).isDirectory,
         "Root directory \""+docPath+"\" not found")
  val deployJar = docPath+sep+Test.name+"_deploy.jar"
  val deployUrl = docRoot+"/"+Test.name+"_deploy.jar"

  def generatePolicyFile() {
    val in = new BufferedReader(new FileReader(policyTmpl))
    val out = new PrintWriter(new BufferedWriter(new FileWriter(policyFile)))
    var line = in.readLine()
    while (line != null) {
      val line1 = line.replaceAll("@PROJECT_LIB_BASE@", codebaseDir)
      out.println(line1)
      line = in.readLine()
    }
    in.close()
    out.close()
  }

  def generateRmiStubs(classNames: List[String]) {
    val options = List(
      "-v1.2",
      "-classpath "+libPath+File.pathSeparator+outPath,
      "-d "+outPath)
    rmic(options, classNames)
    //ls(outPath)
  }

  def generateJarFile(classNames: List[String]) {
    val out = new JarOutputStream(new FileOutputStream(deployJar))
    classNames foreach (name => try {
      val classFile = name+".class"
      val in = new FileInputStream(outPath+sep+classFile)
      out putNextEntry new JarEntry(classFile)
      val buf = new Array[Byte](512)
      var len = in read buf
      while (len != -1) {
        out.write(buf, 0, len)
        len = in read buf
      }
      in.close()
    } catch {
      case e: FileNotFoundException => println(e)
    })
    out.close()
  }

  private def ls(path: String) { exec("ls -al "+path) }

  private def rmic(options: List[String], classNames: List[String]) {
    val javaHome = scala.util.Properties.javaHome
    val jdkHome =
      if (javaHome endsWith "jre") javaHome.substring(0, javaHome.length-4)
      else javaHome
    val rmicExt = if (scala.util.Properties.isWin) ".exe" else ""
    val rmicCmd = jdkHome+sep+"bin"+sep+"rmic"+rmicExt
    val cmdLine = rmicCmd+options.mkString(" ", " ", "")+
                          classNames.mkString(" "," ","")
    // println(cmdLine)
    exec(cmdLine)
  }

  private def exec(command: String) {
    val proc = Runtime.getRuntime exec command
    proc.waitFor()
    val out = new BufferedReader(new InputStreamReader(proc.getInputStream))
    var line = out.readLine()
    while (line != null) {
      println(line)
      line = out.readLine()
    }
    out.close()
    val err = new BufferedReader(new InputStreamReader(proc.getErrorStream))
    line = err.readLine()
    while (line != null) {
      println(line)
      line = err.readLine()
    }
    err.close()
  }
}