import java.io.IOException;
import java.io.EOFException;
import java.io.Serializable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.BufferedOutputStream;
import java.io.ObjectOutputStream;
import java.io.BufferedInputStream;
import java.io.ObjectInputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

public class SerialIO {

  public static void main(String[] args) throws IOException, ClassNotFoundException {

    StringBuffer name = new StringBuffer();
    int[] grades = {0,0,0,0,0};
    char c = ' ';

//Create directory and file objects.
    File myDir = new File("testdir");
    File textFile = new File(myDir,"StudentData.txt");

//Set up for input from text file.
    FileInputStream textStream = new FileInputStream(textFile);
    FileChannel textChannel = textStream.getChannel();
    ByteBuffer textBuf = ByteBuffer.allocate(4000);

//Set up for file output.
    File dataFile = new File(myDir,"StudentData");
    FileOutputStream outStream = new FileOutputStream(dataFile);
    ObjectOutputStream outData =
      new ObjectOutputStream(new BufferedOutputStream(outStream));

//Read data from input file.
    textChannel.read(textBuf);
    textBuf.flip();
//Get name from text buffer.
    while(textBuf.hasRemaining()){
      name.setLength(0);
      while((c = (char)textBuf.get()) != '\r') //Read up to and including return char
        name.append(c);
      c = (char)textBuf.get(); //Consume new line char
      System.out.println(name);
//Get grades from text buffer.
      int numgrades = 0;
      while((c = (char)textBuf.get()) != '\r') {
        grades[numgrades] = 10*Character.digit(c,10) + Character.digit((char)textBuf.get(),10);
        numgrades++;
      }
      c = (char)textBuf.get(); //Consume new line char
      
//Create Student object.
      Student aStudent = new Student(name,grades,numgrades);

//Write Student object.
      outData.writeObject(aStudent);    
    }
    textStream.close();
    outData.close();

//Read data back in.
    FileInputStream inStream = null;
    try{
      inStream = new FileInputStream(dataFile);
      ObjectInputStream inData =
        new ObjectInputStream(new BufferedInputStream(inStream));
      while(true) {
        Student aStudent = (Student)inData.readObject();
        System.out.println(aStudent.name);
        System.out.println(aStudent.grades[aStudent.grades.length-1]);
      }
    } catch(EOFException e) {
        inStream.close(); 
    }
  }
}