trying out scala

gistfile1.scala

package scalaapplication1

import java.io._
import java.util.Scanner
import javax.swing.JFileChooser
import javax.swing.JOptionPane

object Main {

  def main(args: Array[String]): Unit = {
    try {
      val fc = new JFileChooser()
      val status = fc.showOpenDialog(null)
      val data = fc.getSelectedFile()

      val s = new Scanner(new BufferedReader(new FileReader(data)))

      while(s.hasNextLine()) {
        var transaction = scanTransaction(s)
        transaction match {
          case Array("SUMMARY",_,_,_) => scanSummary(s, transaction)
        }
      }
    }
    catch {
      case e: FileNotFoundException => e.printStackTrace()
      case e: Exception => {
        if(e.getMessage().startsWith("Summary")) {
          JOptionPane.showMessageDialog(null, e.getMessage())
        }
      }
    }
  }

  def scanSummary(s: Scanner, summary: Array[String]): Unit = {
    val expected = scanMoney(summary)
    var value = 0.00d

    for(i <- 0 to (summary(3).toInt - 1)) {
      var transaction = scanTransaction(s)
      value += scanMoney(transaction)

      if(transaction.length == 4) transaction(0) match {
        case "SUMMARY" => scanSummary(s, transaction)
      }
    }
    
    if (!(Math.abs(value - expected) < 0.00001)) {
      throw new Exception("Summary error on %s.\nAmount is $%.2f but should be $%.2f".format(summary(1), expected, value));
    }
  }

  def scanTransaction(s: Scanner): Array[String] = {
    val line = s.nextLine().trim()
    return line.split("\\s+");
  }

  def scanMoney(transaction: Array[String]): Double = {
    return transaction(2).substring(1).toDouble
  }
}