Registration actions

import java.io.FileNotFoundException;import java.io.FileReader;import java.util.LinkedList;import java.util.ListIterator;import java.util.Scanner;public class RegistrationActions{	public LinkedList<Student> Registration()	{		LinkedList<Student> students = Student.readStudents();		try		{			Scanner actions = new Scanner(new FileReader("registration.txt"));			String toDo;			int stuNum;						while (actions.hasNext())			{				ListIterator<Student> mark = students.listIterator();				String hold = actions.next();				Student stu = null;								int test = Integer.parseInt(hold);				while (mark.hasNext())				{					stu = mark.next();					stuNum = stu.getStudentNumber();										// if the student is found					if (test == stuNum)						break;				}											toDo = actions.next();						if (toDo.equalsIgnoreCase("A"))						{							ListIterator<Offering> alreadyHave = RegistrationSystem									.getAllOfferings().listIterator();							boolean found = false;							String holding = actions.next();							short ref = Short.parseShort(holding);							for (int i = 0; i < stu.getNumberCourses();i++)							{								Offering course = alreadyHave.next();								short check = course.reference;								if (check == ref)								{									found = true;									stu.addCourse(course);									break;								}															}														if (found == false)							{								Offering course = new Offering(ref);								RegistrationSystem.getAllOfferings().addLast(										course);								stu.addCourse(course);								System.out.println("Course added");								// break;							}						} else if (toDo.equalsIgnoreCase("D"))						{							Offering course = new Offering();							String holder = actions.next();							short ref = Short.parseShort(holder);							course.setReference(ref);							stu.dropCourse(course);							System.out.println("Course dropped");							break;						}										}																				} catch (FileNotFoundException e)		{			System.out.println("Registration File not found.");			System.exit(1);		}	return students;	}}