random file access and GUI

[leiferouis]

I have two assignments i must complete in two days which I don't know much about.
The first one:

Write a program which allows the user to manage a random file of 15 maximum students who are taking this on-line course. Each student can have 6 different marks assigned to them: Thinking, Applications, Communications, Thinking, Exam, and Final Mark. Use the percentage breakdowns for this course to determine the final mark. Because students in on-line courses are at different points in the course, random access has been choosen. From a menu give the user the following options:

* enter initial class list of all student names
* add/delete a student
* enter a mark (Thinking, Applicatinos, Communications, Knowledge or Exam)
* modify a mark (Thinking, Applicatinos, Communications, Knowledge or Exam)
* calculate final mark

For this assignment, I am having trouble figuring out how to tackle the assignment. I am thinking of doing arrays but I don't know how to random file access with arrays. Also I'm not sure whether I should read the file under each function.
The second one: is about GUI. For now, I just need some good resources on GUI.

[leiferouis]

Here is my current class for the file accessing. This is only to contain methods of random file access, the actual menu, inputting and stuff is in a separate class.

// A class which defines a student record - StudentRecord
import java.io.*;
public class StudentRecord
{
    protected int studentnum;       
    protected String name;          
    protected int thinking, application, communication, knowledge, exam;    
    protected double finalmark;      
    protected static final int RECORD_SIZE = 57;

    // Constructor to read record from file
    public StudentRecord (RandomAccessFile input) throws IOException
    {
        //read student number
        studentnum = input.readInt();
        // read student name
        byte[] nameBytes = new byte [30];
        input.readFully (nameBytes);
        name = new String (nameBytes, 0);
        //read marks
        thinking = input.readInt();
        application = input.readInt();
        communication = input.readInt();
        knowledge = input.readInt();
        exam = input.readInt();
        finalmakr = input.readDouble();        
    }


    // Constructor uses data from keyboard
    public StudentRecord (int studentnum, String name, int thinking, int application, int communication, int knowledge, int exam, double finalmark)
    {
        this.studentnum = studentnum;
        this.name = name;
        this.thinking = thinking;
        this.application = application;
        this.communication = communication;
        this.knowledge = knowledge;
        this.exam = exam;
        this.finalmark = finalmark;
    }



    // Method to get student number
    public int getStudentnumber ()
    {
        return studentnum;
    }


    // Method to get student name
    public String getName ()
    {
        return name;
    }


    // Method to get thinking
    public String getThinking ()
    {
        return thinking;
    }


    // Method to get application
    public double getApplication ()
    {
        return application;
    }

    //Method to get communication
    public int getCommunication ()
    {
        return communication;
    }


    // Method to get knowledge
    public int getknowledge ()
    {
        return knowledge;
    }

    //Method to get exam
    public int getExam ()
    {
        return exam;
    }


    // Method to get final mark
    public int getFinalmark ()
    {
        return finalmark;
    }

    // Method to get record size.
    public static int recordSize ()
    {
        return RECORD_SIZE;
    }


    // Method to write a record to file.
    public void write (RandomAccessFile output) throws IOException
    {
        //output student number
        output.writeInt(studentnum);
        //output student name
        name=fillspace(name,30);
        byte[] nameBytes = new byte [30];
        name.getBytes(0, name.length (), nameBytes, 0);
        output.write(nameBytes);
        //output marks
        output.writeInt(thinking);
        output.writeInt(application);
        output.writeInt(knowledge);
        output.writeInt(communication);
        output.writeInt(exam);
        output.writeDouble(finalmark);
    }


    // Method to fill extra string room with spaces
    public static String fillspace (String word, int lengthtofill)
    {
        int stringlength, x;
        stringlength = word.length ();
        for (x = stringlength; x <= lengthtofill-1 ; x++)
        {
            word = word + " ";
        }
        return word;
    }
}

My biggest problem is with the main class... I don't really understand how the data goes into an actual file.