이름, 국어, 영어, 수학, 과학 점수를 얻어와서 Student형 객체에 파일 기록하는건데
import java.io.*;
import java.util.*;

public class Student implements Serializable {
 String name;
 int[] record = new int[4];
 int total;
 float avg;
 String grade;
 Student(String name,int kor, int eng, int mat, int sci){
  this.name = name;
  record[0]=kor;
  record[1]=eng;
  record[2]=mat;
  record[3]=sci;
  total=kor+eng+mat+sci;
  avg=total/4.0f;
  if(avg>=90)grade="A";
  else if(avg>=80)grade="B";
  else if(avg>=70)grade="C";
  else if(avg>=80)grade="D";
  else grade="F";
 }
 float getAvg(){
  return avg;
 }
 String getName(){
  return name;
 }
 String getGrade(){
  return grade;
 }
 public String toString(){
  return name +" "+record[0]+" "+record[1]+" "+record[2]+" "+record[3]+" "+total+" "+avg+" "+grade;
 }
}
랑
import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.util.StringTokenizer;

public class SerializableTest{
  public static void main(String[] args)throws Exception{
  
   BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
   ObjectOutputStream oos=new ObjectOutputStream(new FileOutputStream("c:\\\\student.dat"));
   while(true){
    String str=br.readLine();
    if(str.equals("eof"))break;
    
    StringTokenizer stok = new StringTokenizer(str);
    String arg1= stok.nextToken();
    int arg2=Integer.parseInt(stok.nextToken());
    int arg3=Integer.parseInt(stok.nextToken());
    int arg4=Integer.parseInt(stok.nextToken());
    int arg5=Integer.parseInt(stok.nextToken());
    oos.writeObject(new Student(arg1,arg2,arg3,arg4,arg5));
    
   }
   oos.close();
 }

}
해서 dat 파일 만들었는데
dat파일을 어케 읽어와야 돼나 ㅡ,.ㅡ 너무 어렵나;;;