Scala example source code file (serialization.scala)

This example Scala source code file (serialization.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

a, array, b, bitset, error, exception, int, int, list, list, person, person, string, string

The Scala serialization.scala source code

//############################################################################
// Serialization
//############################################################################

object Serialize {
  @throws(classOf[java.io.IOException])
  def write[A](o: A): Array[Byte] = {
    val ba = new java.io.ByteArrayOutputStream(512)
    val out = new java.io.ObjectOutputStream(ba)
    out.writeObject(o)
    out.close()
    ba.toByteArray()
  }
  @throws(classOf[java.io.IOException])
  @throws(classOf[ClassNotFoundException])
  def read[A](buffer: Array[Byte]): A = {
    val in =
      new java.io.ObjectInputStream(new java.io.ByteArrayInputStream(buffer))
    in.readObject().asInstanceOf[A]
  }
  def check[A, B](x: A, y: B) {
    println("x = " + x)
    println("y = " + y)
    println("x equals y: " + (x equals y) + ", y equals x: " + (y equals x))
    assert((x equals y) && (y equals x))
    println()
  }
}
import Serialize._

//############################################################################
// Test classes in package "scala"

object Test1_scala {

  private def arrayToString[A](arr: Array[A]): String =
    arr.mkString("Array[",",","]")

  private def arrayEquals[A, B](a1: Array[A], a2: Array[B]): Boolean =
    (a1.length == a2.length) &&
    (Iterator.range(0, a1.length) forall { i => a1(i) == a2(i) })

  object WeekDay extends Enumeration {
    type WeekDay = Value
    val Monday, Tuesday, Wednesday, Thusday, Friday, Saturday, Sunday = Value
  }
  import WeekDay._, BigDecimal._, RoundingMode._

  // in alphabetic order
  try {
    // Array
    val a1 = Array(1, 2, 3)
    val _a1: Array[Int] = read(write(a1))
    println("a1 = " + arrayToString(a1))
    println("_a1 = " + arrayToString(_a1))
    println("arrayEquals(a1, _a1): " + arrayEquals(a1, _a1))
    println()

    // Cell
    val c1 = new Cell('a')
    val _c1: Cell[Char] = read(write(c1))
    println("c1 = " + c1)
    println("_c1 = " + _c1)
    println("c1 eq _c1: " + (c1 eq _c1) + ", _c1 eq c1: " + (_c1 eq c1))
    println("c1 equals _c1: " + (c1 equals _c1) + ", _c1 equals c1: " + (_c1 equals c1))
    println()

    // Either
    val e1 = Left(1)
    val _e1: Either[Int, String] = read(write(e1))
    println("e1 = " + e1)
    println("_e1 = " + _e1)
    println("e1 eq _e1: " + (e1 eq _e1) + ", _e1 eq e1: " + (_e1 eq e1))
    println("e1 equals _e1: " + (e1 equals _e1) + ", _e1 equals e1: " + (_e1 equals e1))
    println()

    // Enumeration
    val x7 = BigDecimal.RoundingMode
    val y7: RoundingMode.type = read(write(x7))
    println("x7 = " + x7)
    println("y7 = " + y7)
    println("x7 eq y7: " + (x7 eq y7) + ", y7 eq x7: " + (y7 eq x7))
    println("x7 equals y7: " + (x7 equals y7) + ", y7 equals x7: " + (y7 equals x7))
    println()

    val x8 = WeekDay
    val y8: WeekDay.type = read(write(x8))
    println("x8 = " + x8)
    println("y8 = " + y8)
    println("x8 eq y8: " + (x8 eq y8) + ", y8 eq x8: " + (y8 eq x8))
    println("x8 equals y8: " + (x8 equals y8) + ", y8 equals x8: " + (y8 equals x8))
    println()

    val x9 = UP
    val y9: RoundingMode = read(write(x9))
    println("x9 = " + x9)
    println("y9 = " + y9)
    println("x9 eq y9: " + (x9 eq y9) + ", y9 eq x9: " + (y9 eq x9))
    println("x9 equals y9: " + (x9 equals y9) + ", y9 equals x9: " + (y9 equals x9))
    println()

    val x10 = Monday
    val y10: WeekDay = read(write(x10))
    println("x10 = " + x10)
    println("y10 = " + y10)
    println("x10 eq y10: " + (x10 eq y10) + ", y10 eq x10: " + (y10 eq x10))
    println("x10 equals y10: " + (x10 equals y10) + ", y10 equals x10: " + (y10 equals x10))
    println()

    println("x9 eq x10: " + (x9 eq x10) + ", x10 eq x9: " + (x10 eq x9))
    println("x9 equals x10: " + (x9 equals x10) + ", x10 equals x9: " + (x10 equals x9))
    println("x9 eq y10: " + (x9 eq y10) + ", y10 eq x9: " + (y10 eq x9))
    println("x9 equals y10: " + (x9 equals y10) + ", y10 equals x9: " + (y10 equals x9))
    println()

    // Function
    val f1 = { x: Int => 2 * x }
    val _f1: Function[Int, Int] = read(write(f1))
    println("f1 = <na>")
    println("_f1 = <na>")
    println("f1(2): " + f1(2) + ", _f1(2): " + _f1(2))
    println()

    // List
    val xs0 = List(1, 2, 3)
    val _xs0: List[Int] = read(write(xs0))
    println("xs0 = " + xs0)
    println("_xs0 = " + _xs0)
    println("xs0 eq _xs0: " + (xs0 eq _xs0) + ", _xs0 eq xs0: " + (_xs0 eq xs0))
    println("xs0 equals _xs0: " + (xs0 equals _xs0) + ", _xs0 equals xs0: " + (_xs0 equals xs0))
    println()

    val xs1 = Nil
    val _xs1: List[Nothing] = read(write(xs1))
    println("xs1 = " + xs1)
    println("_xs1 = " + _xs1)
    println("xs1 eq _xs1: " + (xs1 eq _xs1) + ", _xs1 eq xs1: " + (_xs1 eq xs1))
    println()

    // Option
    val o1 = None
    val _o1: Option[Nothing] = read(write(o1))
    println("o1 = " + o1)
    println("_o1 = " + _o1)
    println("o1 eq _o1: " + (o1 eq _o1) + ", _o1 eq o1: " + (_o1 eq o1))
    println()

    val o2 = Some(1)
    val _o2: Option[Int] = read(write(o2))
    println("o2 = " + o2)
    println("_o2 = " + _o2)
    println("o2 eq _o2: " + (o2 eq _o2) + ", _o2 eq o2: " + (_o2 eq o2))
    println("o2 equals _o2: " + (o2 equals _o2) + ", _o2 equals o2: " + (_o2 equals o2))
    println()
/*
    // Responder
    val r1 = Responder.constant("xyz")
    val _r1: Responder[String] = read(write(r1))
    check(r1, _r1)
*/
    // Symbol
    val s1 = 'hello
    val _s1: Symbol = read(write(s1))
    println("s1 = " + s1)
    println("_s1 = " + _s1)
    println("s1 eq _s1: " + (s1 eq _s1) + ", _s1 eq s1: " + (_s1 eq s1))
    println("s1 equals _s1: " + (s1 equals _s1) + ", _s1 equals s1: " + (_s1 equals s1))
    println()

    // Tuple
    val t1 = ("BannerLimit", 12345)
    val _t1: (String, Int) = read(write(t1))
    println("t1 = " + t1)
    println("_t1 = " + _t1)
    println("t1 eq _t1: " + (t1 eq _t1) + ", _t1 eq t1: " + (_t1 eq t1))
    println("t1 equals _t1: " + (t1 equals _t1) + ", _t1 equals t1: " + (_t1 equals t1))
    println()
  }
  catch {
    case e: Exception =>
      println("Error in Test1_scala: " + e)
      throw e
  }
}

//############################################################################
// Test classes in package "scala.collection.immutable"

object Test2_immutable {
  import scala.collection.immutable.{
    BitSet, HashMap, HashSet, ListMap, ListSet, Queue, Range, SortedMap,
    SortedSet, Stack, Stream, TreeMap, TreeSet, Vector}

  // in alphabetic order
  try {
    // BitSet
    val bs1 = BitSet.empty + 1 + 2
    val _bs1: BitSet = read(write(bs1))
    check(bs1, _bs1)

    val bs2 = {
      val bs = new collection.mutable.BitSet()
      bs += 2; bs += 3
      bs.toImmutable
    }
    val _bs2: BitSet = read(write(bs2))
    check(bs2, _bs2)

    // HashMap
    val hm1 = new HashMap[Int, String] + (1 -> "A", 2 -> "B", 3 -> "C")
    val _hm1: HashMap[Int, String] = read(write(hm1))
    check(hm1, _hm1)

    // HashSet
    val hs1 = new HashSet[Int] + 1 + 2
    val _hs1: HashSet[Int] = read(write(hs1))
    check(hs1, _hs1)

    // List
    val xs1 = List(("buffers", 20), ("layers", 2), ("title", 3))
    val _xs1: List[(String, Int)] = read(write(xs1))
    check(xs1, _xs1)

    // ListMap
    val lm1 = new ListMap[String, Int] + ("buffers" -> 20, "layers" -> 2, "title" -> 3)
    val _lm1: ListMap[String, Int] = read(write(lm1))
    check(lm1, _lm1)

    // ListSet
    val ls1 = new ListSet[Int] + 3 + 5
    val _ls1: ListSet[Int] = read(write(ls1))
    check(ls1, _ls1)

    // Queue
    val q1 = Queue("a", "b", "c")
    val _q1: Queue[String] = read(write(q1))
    check(q1, _q1)

    // Range
    val r1 = 0 until 10
    val _r1: Range = read(write(r1))
    check(r1, _r1)

    val r2 = Range.Long(0L, 10L, 1)
    val _r2: r2.type = read(write(r2))
    check(r2, _r2)

    // SortedMap
    val sm1 = SortedMap.empty[Int, String] + (2 -> "B", 3 -> "C", 1 -> "A")
    val _sm1: SortedMap[Int, String] = read(write(sm1))
    check(sm1, _sm1)

    // SortedSet
    val ss1 = SortedSet.empty[Int] + 2 + 3 + 1
    val _ss1: SortedSet[Int] = read(write(ss1))
    check(ss1, _ss1)

    // Stack
    val s1 = new Stack().push("a", "b", "c")
    val _s1: Stack[String] = read(write(s1))
    check(s1, _s1)

    // Stream
    val st1 = Stream.range(0, 10)
    val _st1: Stream[Int] = read(write(st1))
    check(st1, _st1)

    // TreeMap
    val tm1 = new TreeMap[Int, String] + (42 -> "FortyTwo")
    val _tm1: TreeMap[Int, String] = read(write(tm1))
    check(tm1, _tm1)

    // TreeSet
    val ts1 = new TreeSet[Int]() + 2 + 0
    val _ts1: TreeSet[Int] = read(write(ts1))
    check(ts1, _ts1)

    // Vector
    val v1 = Vector('a, 'b, 'c)
    val _v1: Vector[Symbol] = read(write(v1))
    check(v1, _v1)
  }
  catch {
    case e: Exception =>
      println("Error in Test2_immutable: " + e)
      throw e
  }
}

//############################################################################
// Test classes in package "scala.collection.mutable"

object Test3_mutable {
  import scala.reflect.ClassManifest
  import scala.collection.mutable.{
    ArrayBuffer, ArrayBuilder, ArraySeq, ArrayStack, BitSet, DoubleLinkedList,
    HashMap, HashSet, History, LinkedList, ListBuffer, Publisher, Queue,
    Stack, StringBuilder, WrappedArray}

  // in alphabetic order
  try {
    // ArrayBuffer
    val ab1 = new ArrayBuffer[String]
    ab1 ++= List("one", "two")
    val _ab1: ArrayBuffer[String] = read(write(ab1))
    check(ab1, _ab1)
    
    // ArrayBuilder
    val abu1 = ArrayBuilder.make[Long]
    val _abu1: ArrayBuilder[ClassManifest[Long]] = read(write(abu1))
    check(abu1, _abu1)

    val abu2 = ArrayBuilder.make[Float]
    val _abu2: ArrayBuilder[ClassManifest[Float]] = read(write(abu2))
    check(abu2, _abu2)
    
    // ArraySeq
    val aq1 = ArraySeq(1, 2, 3)
    val _aq1: ArraySeq[Int] = read(write(aq1))
    check(aq1, _aq1)
    
    // ArrayStack
    val as1 = new ArrayStack[Int]
    as1 ++= List(20, 2, 3).iterator
    val _as1: ArrayStack[Int] = read(write(as1))
    check(as1, _as1)

    // BitSet
    val bs1 = new BitSet()
    bs1 += 0
    bs1 += 8
    bs1 += 9
    val _bs1: BitSet = read(write(bs1))
    check(bs1, _bs1)
/*
    // DoubleLinkedList
    val dl1 = new DoubleLinkedList[Int](2, null)
    dl1.append(new DoubleLinkedList(3, null))
    val _dl1: DoubleLinkedList[Int] = read(write(dl1))
    check(dl1, _dl1)
*/
    // HashMap
    val hm1 = new HashMap[String, Int]
    hm1 ++= List(("A", 1), ("B", 2), ("C", 3)).iterator
    val _hm1: HashMap[String, Int] = read(write(hm1))
    check(hm1, _hm1)

    // HashSet
    val hs1 = new HashSet[String]
    hs1 ++= List("layers", "buffers", "title").iterator
    val _hs1: HashSet[String] = read(write(hs1))
    check(hs1, _hs1)

    val h1 = new History[String, Int]
    val _h1: History[String, Int] = read(write(h1))
    check(h1, _h1)
/*
    // LinkedList
    val ll1 = new LinkedList[Int](2, null)
    ll1.append(new LinkedList(3, null))
    val _ll1: LinkedList[Int] = read(write(ll1))
    check(ll1, _ll1)
*/
    // ListBuffer
    val lb1 = new ListBuffer[String]
    lb1 ++= List("white", "black")
    val _lb1: ListBuffer[String] = read(write(lb1))
    check(lb1, _lb1)

    // Queue
    val q1 = new Queue[Int]
    q1 ++= List(20, 2, 3).iterator
    val _q1: Queue[Int] = read(write(q1))
    check(q1, _q1)

    // Stack
    val s1 = new Stack[Int]
    s1 pushAll q1
    val _s1: Stack[Int] = read(write(s1))
    check(s1, _s1)

    // StringBuilder
    val sb1 = new StringBuilder
    sb1 append "abc"
    val _sb1: StringBuilder = read(write(sb1))
    check(sb1, _sb1)

    // WrappedArray
    val wa1 = WrappedArray.make(Array(1, 2, 3))
    val _wa1: WrappedArray[Int] = read(write(wa1))
    check(wa1, _wa1)
  }
  catch {
    case e: Exception =>
      println("Error in Test3_mutable: " + e)
      throw e
  }
}


//############################################################################
// Test classes in package "scala.xml"

object Test4_xml {
  import scala.xml.{Attribute, Document, Elem, Null, PrefixedAttribute, Text}

  case class Person(name: String, age: Int)

  try {
    // Attribute
    val a1 = new PrefixedAttribute("xml", "src", Text("hello"), Null)
    val _a1: Attribute = read(write(a1))
    check(a1, _a1)

    // Document
    val d1 = new Document
    d1.docElem = <title>
    d1.encoding = Some("UTF-8")
    val _d1: Document = read(write(d1))
    check(d1, _d1)

    // Elem
    val e1 = <html>;
    val _e1: Elem = read(write(e1))
    check(e1, _e1)

    class AddressBook(a: Person*) {
      private val people: List[Person] = a.toList
      def toXHTML =
      <table cellpadding="2" cellspacing="0">
        <tr>
          <th>Last Name
          <th>First Name
        </tr>
        { for (p <- people) yield
        <tr>
          <td> { p.name }