package ex2.data;

//import java.util.ArrayList;

/**
 * Η κλάση Student παριστά ένα φοιτητή στο σύστημα του φοιτητολογίου. 
 * Η κλάση κληρονομεί την κλάση {@link Person}.
 * Student's extra attributes: Student Id, Semester
 * @author Ioulia Anastasiou, Iraklis Lefas, Alexandros Feidis
 */

public class Student extends Person
{
    private String StudId;
    private int Semester;
    //private Course[] Studies;
    //private ArrayList <Course> Studies;

    // constructor

    /**
     * @param SurName :person's surname
     * @param FirstName :person's first name
     * @param FatherName :person's father name
     * @param BirthYear :person's birth year
     * @param EMail :person's email addNewStrs
     * @param PhoneNo :person's phone number 
     * @param StudId :student's unique identification number 
     * @param Semester :student's semester
     */

    public Student (String SurName, String FirstName, String FatherName, int BirthYear, String EMail, String PhoneNo, String StudId, String Semester)
    {
        super (SurName, FirstName, FatherName, BirthYear, EMail, PhoneNo); //inherited from class PERSON
        this.StudId = StudId;
        this.Semester = Semester;
        //Studies = new ArrayList ();
    }

    //getters&setters
    public String getStudId ()
    {
        return StudId;
    }

     public void setStudId (String StudId)
    {
        this.StudId = StudId;
    }

    public int getSemester ()
    {
        return Semester;
    }

    public void setSemester (int Semester)
    {
        this.Semester = Semester;
    }

    /**
     * shows all data for a student
     */
    @Override
    public void ShowAll()
      {  
        super.ShowAll();   
        System.out.println ("Professor's Id.........:" + ProfId);
        System.out.println ("Student's Id...........:" + StudId);
        System.out.println ("Student's Semester.....:" + Semester);
      }

    /**
     * returns all data in one string
    */
    @Override
    public String toString ()
    {
        String OneString;
        OneString = super.toString() + "  /  " + StudId + "  /  " + Semester; 
        return OneString;
    }
}package ex2.data;

import java.util.ArrayList;

/**
 * Η κλάση Professor παριστά έναν καθηγητή στο σύστημα του φοιτητολογίου. 
 * Η κλάση κληρoνομεί την κλάση {@link Person}.
 * Proffesor's extra attributes: Teacher Id, Specialism
 * @author Ioulia Anastasiou, Iraklis Lefas, Alexandros Feidis
 */

public class Professor extends Person
{
    private String ProfId;
    //private ArrayList <Course> Teaches;
    private String Specialism;
    
    // constructor
    /**
     * 
     * @param SurName :person's surname
     * @param FirstName :person's first name
     * @param FatherName :person's father name
     * @param BirthYear :person's birth year
     * @param EMail :person's email addNewStrs
     * @param PhoneNo :person's phone number 
     * @param ProfId :professor's unique identification number
     * @param Expertise :professor's science expertise  
     * //@param Teaches :courses that the professor teaches
     */

    public Professor (String SurName, String FirstName, String FatherName, int BirthYear, String EMail, String PhoneNo, String ProfId, String Specialism)
    {
        super (SurName, FirstName, FatherName, BirthYear, EMail, PhoneNo); //inherited from class PERSON
        this.ProfId = ProfId;
        this.Specialism = Specialism;
        //Teaches = new ArrayList ();
    }

    //getters&setters
    public String getProfId ()
    {
        return ProfId;
    }

    public void setProfId (String ProfId)
    {
        this.ProfId = ProfId;
    }

    public String getSpecialism()
    {
        return Specialism;
    }

    public void setSpecialism (String Specialism)
    {
        this.Specialism = Specialism;
    }

    /*public ArrayList <Course> getTeaches ()
    {
        return Teaches; //no need here, as the Teaches function is performed in Person class
    } */

    /**
     * shows all data for a professor
     */
    @Override
    public void ShowAll()
      {  
        super.ShowAll();   
        System.out.println ("Professor's Id.........:" + ProfId);
        System.out.println ("Professor's Specialism :" + Specialism);
      }

    /**
     * returns all data in one string
    */
    @Override
    public String toString ()
    {
        String OneString;
        OneString = super.toString() + "  /  " + ProfId + "  /  " + Specialism; 
        return OneString;
    }
}
package ex2.data;

import java.util.Date;
import java.util.ArrayList;

/**
 * Η κλάση Person παριστά ένα άτομο. Περιέχει τα χαρακτηριστικά του 
 * ενός ατόμου τα οποία ενδιαφέρουν την εφαρμογή του φοιτητολογίου και 
 * τις αντίστοιχες λειτουργίες, δηλ. τα κοινά στοιχεία φοιτητών και καθηγητών, 
 * τα οποία κληρονομούνται από τις αντίστοιχες κλάσεις.
 * @author Ioulia Anastasiou, Iraklis Lefas, Alexandros Feidis
 */

public class Person
{
    protected String SurName;
    protected String FirstName;
    protected String FatherName;
    protected int BirthYear;
    protected String EMail;
    protected String PhoneNo;
    protected ArrayList <Course> Courses;
    //protected String IDNum;
    // private static int Counter = 0;
    
    /*
    public static void ShowCounter ()
    {
        System.out.printf ("Μέχρι στιγμής έχουν δημιουργηθεί %d στιγμιότυπα της κλάσης Person\n", Counter);
    }
    */

    // constructor
    /**
     * 
     * @param SurName :person's surname
     * @param FirstName :person's first name
     * @param FatherName :person's father name
     * @param BirthYear :person's birth year
     * @param EMail :person's email addNewStrs
     * @param PhoneNo :person's phone number 
     * @param Courses :person's list of affiliated courses
     */

    public Person (String SurName, String FirstName, String FatherName, int BirthYear, String EMail, String TelNo)
    {
        this.SurName = SurName;
        this.FirstName = FirstName;
        this.FatherName = FatherName;
        this.BirthYear = BirthYear;
        this.EMail = EMail;
        this.PhoneNo = PhoneNo;
        Courses = new ArrayList();
        // Counter++;
    }

    
    // constructor
    /**
     * 
     * @param SN :person's surname
     * @param FN :person's first name
     * @param FaNam :person's father name
     */

    /*
    public Person (String SN, String FN, String FaNam)
    {
        this (SN, FN, FaNam, 0, null);
        //SurName = SN;
        //FirstName = FN;
        //FatherName = FaNam;
        //Counter++;
        
    }
    /*

    /*
    public Person (Person C)
    {
        SurName = C.SurName;
        FirstName = C.FirstName;
        FatherName = C.FatherName;
        BirthYear = C.BirthYear;
        IDNum = C.IDNum;
        //Counter++;
    }
    */

    // getters & setters for person's attributes

    public String getSurName ()
    {
        return SurName;
    }

    public void setSurName (String SurName)
    {
        this.SurName = SurName;
    }

    public String getFirstName ()
    {
        return FirstName;
    }

    public void setFirstName (String FirstName)
    {
        this.FirstName = FirstName;
    }

    public String getFatherName ()
    {
        return FatherName;
    }

    public void setFatherName (String FatherName)
    {
        this.FatherName = FatherName;
    }

    public int getBirthYear ()
    {
        return BirthYear;
    }

    public void setBirthYear (int BirthYear)
    {
        this.BirthYear = BirthYear;
    }

    public String getEMail ()
    {
        return EMail;
    }

    public void setEMail (String EMail)
    {
        this.EMail = EMail;
    }
 
    public String getPhoneNo ()
    {
        return PhoneNo;
    }

    public void setPhoneNo (String PhoneNo)
    {
        this.PhoneNo = PhoneNo;
    }

    public ArrayList<Course> getCourses ()
    {
        return Courses;
    }

    public void setCourses(ArrayList<Course>Courses)
    {
        this.Courses =Courses;
    }  

    /**
     * calculates peson's age to check validity of data
     */
    public int CalcAge (int YY)
    {
        int Age;
        Age = YY - BirthYear;
        return Age;
    }

    /**
     * Adds a new course entry in person's list of courses
     * @param c : course to be added 
    */
    public void AddCourse(Course c)
    {
      Courses.add (c); //namh balw ki edw search gia hascourse?
    }

    /**
    * Deletes a couirse entry from person's list of courses.
    * The course is searched and if not found, no further action is performed.
    *@param CourseId : Id of the course to be deleted  
    * ο κωδικός του μαθήματος που θα αφαιρεθεί από τη λίστα. 
    */
    public void DeleteCourse(String CourseId)
    {
        for(int i = 0;i < Courses.size (); i++)
            {
                if(Courses.get(i).getCourseId().equals (CourseId) || Courses.get(i).getCourseName().equalsIgnoreCase (CourseId)) //oxi equals coursename?
                Courses.remove (i);
            //ena check edw an thelei exception
            }
    }

    /**
    *  Checks if person is affiliated with a course.
    *  Search is performed by course's name or id (use of for:each loop)
    *  The course is searched and if not found, no further action is performed.
    * @param CourseId Id of the course to be searched for
    * @param c : specific course object 
    * @return true: course found / false: course not found. 
    */
    public boolean HasCourse(String CourseId)
    {
      for (Course c: Courses)
        {   // mporuse na ginei kai opws h delets course (oxi xrhsh for:each) ?
            if(c.getCourseId().equals (CourseId) || c.getCourseName().equalsIgnoreCase (CourseID)) //oxi course name?
            return true;
        }
      return false;
    }     

    /**
    * Returns a string of person's course names.
    * If no course has been assigned to person, prints a suitable message
    *@return NewStr: new string that shows the courses
    */
    public String GetNamesOfCourses() 
    {
      String NewStr=""; //alt+F3 to modify all selections in sublime text
      if (this.Courses==null)
        {
            NewStr ="No course has been assigned";
        }
      else
        {
           for (int i=0; i<this.Courses.size(); i++)
           {
                Course tmp=this.Courses.get(i);
                NewStr+=tmp.getCourseName();
                if(i<(this.Courses.size()-1))
                   NewStr+=",";
           }
        }
      return (NewStr);
    }

    /**
     * shows all data for a person
     */

    public void ShowAll ()
    {
        System.out.println ("   PERSON DATA   ");
        System.out.println ("========================");
        System.out.println ("Surname................: " + SurName);
        System.out.println ("Name...................: " + FirstName);
        System.out.println ("Father's Name..........: " + FatherName);
        System.out.println ("Year of birth..........: " + BirthYear);
        System.out.println ("Email..................: " + EMail);
        System.out.println ("Phone Number...........: " + PhoneNo);
    }
    
    /**
     * returns all data in one string
    */
    @Override
    public String toString ()
    {
        String OneString;
        OneString = SurName + "  /  " + FirstName + "  /  " + FatherName + "  /  " + BirthYear + "  /  " + EMail  "  /  " + PhoneNo;
        return OneString;
    }
    
    /**
    checks if bitrh year given is valid
    */
    public static boolean ValidBirthYear (int ToBeChecked)
    {
        if (ToBeChecked > 1900 && ToBeChecked <= new Date ().getYear ())
            return true;
        return false;
    }

}
import ex2.data.Course;
import ex2.data.Person;
import ex2.data.Professor;
import ex2.data.Student;
import ex2.data.Grade;

import java.util.Scanner;

public class StudentSystem
{
Lists MainList;
Scanner input;
public StudentSystem (){
MainList = new Lists();
FixedRecords(); input = new Scanner (System.in , "windows-1253"); //??????
}

//START OF ΜΑΙΝ
public static void main(String[] args){
System.out.println("---------------------");
System.out.println(" STUDENT APPLICATION ");
StudentSystem Final= new StudentSystem();
Final.Menu();
}

public void Menu ()
{
int menu;
do
{
System.out.println ("===========================================");
System.out.println (" MAIN MENU ");
System.out.println ("===========================================");
System.out.println ("1.  Show Professors");
System.out.println ("2.  Show Students");
System.out.println ("3.  Show Courses");
System.out.println ("4.  Show Grades");
System.out.println ("5.  Add New Person");
System.out.println ("6.  Edit Person");
System.out.println ("7.  Delete Person");
System.out.println ("8.  Add New Course");
System.out.println ("9.  Edit Course");
System.out.println ("10. Delete Course");
System.out.println ("11. Assign Course to a Person");
System.out.println ("12. Delete Course from a Person");
System.out.println ("13. Insert grade to a Student");
System.out.println ("14. Show Statistic Information");
System.out.println ("15. Save/Load Data");
System.out.println ("0.  Exit");
System.out.println ("===========================================");
System.out.println("Type your choice please:");
System.out.println("");
do
{
while (!input.hasNextInt())
	{
	System.out.println ("Wrong input! Choice must be integer number from 0 to 15");
	input.next();
	}
	menu=input.nextInt();
	}
while(menu<0);
System.out.println("");
switch (menu)
	{
	case 1: ShowProfessors (); Pause(); break;
	case 2: ShowStudents (); Pause(); break;
	case 3: ShowCourses (); Pause(); break;
	case 4: ShowGrades(); Pause(); break;
	case 5: AddPerson (); Pause(); break;
	case 6: ManipulatePerson (); Pause(); break;
	case 7: DeletePerson (); Pause(); break;
	case 8: AddNewCourse (); Pause(); break;
	case 9: ManipulateCourse (); Pause(); break;
	case 10:DeleteCourse (); Pause(); break;
	case 11:AddCourseToPerson (); Pause(); break;
	case 12:DeleteCourseFromPerson (); Pause(); break;
	case 13:AddGrade(); Pause(); break;
	case 14:AvgAllStudents();AvgAllCourses(); Pause(); break;
	case 15:LoadSaveDialogue(); Pause(); break;
	case 0: break;
	default:
	System.out.println("No such choice exists!!!");
	Pause();
	System.out.println("");
	break;
	}
}
while (menu != 0);
System.out.println ("Exiting...Goodbye!!");
System.out.println("");
}

//Start of data insertion

/** 
* adds fixed entries to the application 
*/

public void FixedRecords ()
{
Course c;
c=new Course("001","PLIROFORIKH",3);
MainList.AddCourse(c);
c=new Course("002","DIKTYA ASFALEIA",1);
MainList.AddCourse(c);
c=new Course("003","VASEIS DEDOMEWN",2);
MainList.AddCourse(c);
Student s;
s=new Student("F0001","ANTONIOU","Antonios","[email protected]","699999999",3);
MainList.AddPerson(s);
s.AddCourse(MainList.GetCourseByID("001"));
s.AddCourse(MainList.GetCourseByID("003"));
s=new Student("F0002","GEORGIOU","Georgios","[email protected]","6988888888",1);
MainList.AddPerson(s);
s.AddCourse(MainList.GetCourseByID("002"));
s=new Student("F0003","DIMITRIOU","Dimitrios","[email protected]","6977777777",2);
MainList.AddPerson(s);
s.AddCourse(MainList.GetCourseByID("003"));
try
{
Grade g1= new Grade("F0001","001",5.2);
MainList.AddGrade(g1);
}
catch (Exception e)
{
System.out.println(e.getMessage());
}
try
{
Grade g2= new Grade("F0001","003",3.2);
MainList.AddGrade(g2);
}
catch (Exception e)
{
System.out.println(e.getMessage());
}
try
{
Grade g3= new Grade("F0002","002",6.2);
MainList.AddGrade(g3);
}
catch (Exception e)
{
System.out.println(e.getMessage());
}
try
{
Grade g4= new Grade("F0003","003",4.2);
MainList.AddGrade(g4);
}
catch (Exception e)
{
System.out.println(e.getMessage());
}
Professor p;
p=new Professor("K005","IOANNOU","Ioannis","[email protected]","65555555555","Pliroforiki");
MainList.AddPerson(p);
p.AddCourse(MainList.GetCourseByID("001"));
p.AddCourse(MainList.GetCourseByID("003"));
p=new Professor("K008","KONSTANTINOU","Konstantinos","[email protected]","63333333333","Diktya");
MainList.AddPerson(p);
p.AddCourse(MainList.GetCourseByID("002"));
p=new Professor("K010","VASILEIOU","Vasileios","[email protected]","622222222","Vaseis Dedomenwn");
MainList.AddPerson(p);
p.AddCourse(MainList.GetCourseByID("003"));
}

/**
* shows the list of professors
* returns the list of professors of @Person class, along with the courses they teach (@GetCourseByID)
*/

public void ShowProfessors()
{
int i=1;
System.out.println ("LIST OF PROFESSORS");
System.out.println ("==================");
System.out.println ("Number Professor_ID Surname Name Email PhoneNo_Number Specialization Course");
System.out.println ("**********************************************************************");
for (Person tmp: MainList.getP_List ())
if(tmp instanceof Professor)
System.out.printf("%2d %-10s %-20s %-20s %-20s %-12s %-20s Didaskei: %s\n",i++,((Professor)tmp ).getProfId(),tmp.getSurName(),tmp.getFirstName (),tmp.getEmail(),tmp.getPhoneNo (),((Professor) tmp).getSpecialism(), tmp.GetCoursesNames()); } 


/**
* shows the list of Students
* returns the list of students of @Person class, along with the courses they attend (@GetCourseByID)
*/

public void ShowStudents()
{
int i=1;
System.out.println ("LISTOF STUDENTS");
System.out.println ("================");
System.out.println ("Number Student_ID Surname Name Email PhoneNo_Number Semester Courses");
System.out.println ("******************************************************************");
for (Person tmp:MainList.getP_List())
if(tmp instanceof Student)
System.out.printf("%2d %-10s %-20s %-20s %-20s %-12s %-10d Parakolouthei: %s\n",i++,((Student)tmp).getStudId(),tmp.getSurName(),tmp.getFirstName (),tmp.getEmail(),tmp.getPhoneNo(),((Student) tmp).getSemester(),tmp.getCourses());
}

/**
* shows the list of courses
* returns the list of courses of @Course class, along with their info
*/

public void ShowCourses()
{
int i=1;
System.out.println ("LIST OF COURSES");
System.out.println ("===============");
System.out.println ("Number Course_ID Course_Title Semester");
System.out.println ("**************************************");
for (Course tmp:MainList.getC_List())
System.out.printf("%2d %-10s %-25s %d\n",i++,tmp.getCourseID(),tmp.getCourseName(),tmp.getCourseSemester());
}


/**
* shows the list of grades
* returns the list of grades of @Grade class, along with ttheir info
*/

public void ShowGrades()
{
int i=1;
System.out.println ("LIST OF GRADES");
System.out.println ("==============");
System.out.println ("Number Course Student Grade");
System.out.println ("***************************");
for (Grade tmp:MainList.getGrades())
System.out.printf("%2d %5s %10s %15f\n",i++,tmp.Grade_Course_Id(),tmp.getGrade_Student_Id(),tmp.getGrade());
}

/**
* adds a new person to the list of persons (choice between student or professor)
* checks: choice number validity, if prof. exists 
*/

public void AddPerson()
{
int option;
System.out.println ("Press 1 to add a new professor");
System.out.println ("Press 2 to add a new student");
System.out.printf ( "Type your choice: ");
do{
while (!input.hasNextInt())
{
System.out.println ("Wrong input! Please choose a number!");
input.next();
}
option= input.nextInt();
}
while(option <=0);
input.nextLine(); //clears the input buffer
if (option==1){
Professor p;
System.out.println ("Type professor's ID:");
String tmpProfId= input.nextLine();
if(MainList.CheckProf(tmpProfId))
{
System.out.println("Professor allready exists");
return;
}
System.out.printf ("Type professor's surname:");
String tmpSurName= input.nextLine();
System.out.printf ("Type professor's first name:");
String tmpFirstName= input.nextLine();
System.out.printf ("Type professor's email:");
String tmpEmail= input.nextLine();
System.out.printf ("Type professor's Phone number:");
String tmpPhoneNo= input.nextLine();
System.out.printf ("Type professor's Specialization:");
String tmpSpecialism= input.nextLine();
p= new Professor(tmpProfId,tmpSurName,tmpFirstName,tmpEmail,tmpPhoneNo,tmpSpecialism);
MainList.AddPerson(p);
System.out.println("Professor inserted!");
}
else if(option==2)
{
Student s;
System.out.printf("Type student's ID number:");
String tmpStudId= input.nextLine();
if(MainList.CheckStudent(tmpStudId))
{
System.out.println("student allready exists!");
return;
}
System.out.printf("Type student's surname: ");
String tmpSurName=input.nextLine();
System.out.printf("Type student's first name: ");
String tmpFirstName=input.nextLine();
System.out.printf("Type student's Email: ");
String tmpEmail=input.nextLine();
System.out.printf("Type student's PhoneNo number: ");
String tmpPhoneNo=input.nextLine();
System.out.printf("Type student's Semester: ");
int tmpSemester;
do{
while (!input.hasNextInt()) {
System.out.println ("Wrong input! Please choose a valid number!");
input.next();
}
tmpSemester= input.nextInt();
}while (tmpSemester<= 0);
s=new Student(tmpStudId, tmpSurName, tmpFirstName, tmpEmail, tmpPhoneNo, tmpSemester);
MainList.AddPerson(s);
System.out.println ("Student sucessfully inserted! ");
}
else{
System.out.println ("NO SUCH CHOICE EXISTS");
}
}

/**
 * edits a person's data in the list of persons and prints the edited entry afterwards.
 * checks: semester number validity, if person not exists, confirm the edit
*/
public void ManipulatePerson() {
char option;
input.nextLine();// clear the input buffer
System.out.printf ("Type person's to be edited data:\n ");
System.out.printf ("Type surname: ");
String tmpSurName = input.nextLine();
System.out.printf ("Type name: ");
String tmpFirstName = input.nextLine();
Person tmpP = MainList.FindPerson (tmpSurName, tmpFirstName);
if(!MainList.CheckPerson(tmpP)) {
return;
}
System.out.println("");
System.out.printf ("\"confirm the edit:\n"+ tmpP + " \nY/N?: ");
do{
option = input.next().charAt (0);
input.nextLine();// clear the input buffer
if(option=='N' || option=='n' || option=='N' || option=='v')
break;
else if (option=='Y' || option!='y' || option=='Y' || option!='υ')
{
System.out.printf("type new surname: ");
String newSurName=input.nextLine();
tmpP.setSurName(newSurName);
System.out.printf("type new name: ");
String newFirstName=input.nextLine();
tmpP.setFirstName(newFirstName);       // na balw kai father name: FatherName
System.out.printf("type new Email: ");
String newEmail=input.nextLine();
tmpP.setEmail(newEmail);
System.out.printf("type new Phone number: ");
String newPhoneNo=input.nextLine();
tmpP.setPhoneNo(newPhoneNo);
if(tmpP instanceof Student){
System.out.printf("type new student ID: ");
String newStudId = input.nextLine();
((Student) tmpP).setAM(newStudId);
System.out.printf("type new Semester: ");
int newSemester;
do {
while (!input.hasNextInt()){
System.out.println("Wrong input! Please choose a number!");
input.next();
}
newSemester = input.nextInt();
}while (newSemester <= 0);
((Student) tmpP).setSemester(newSemester);
}
else if (tmpP instanceof Professor) {
System.out.printf("Type new professor's ID: ");
String newProfId = input.nextLine();
((Professor) tmpP).setProfId(newProfId);
System.out.printf("Type new professor's Specialization: ");
String newSpecialism = input.nextLine();
((Professor) tmpP).setSpecialism(newSpecialism);
}
}
System.out.println("");
System.out.println ("New entry:\n "+ tmpP);
}while(option=='N' || option=='n' || option=='N' || option=='v');
}

/**
 * deletes a person from the list of persons
 * checks: if person exists, confirm the deletion
 */

public void DeletePerson(){
char option;
input.nextLine();//clean input buffer
System.out.printf("Type person's data to be deleted:\n ");
System.out.printf("type surname:");
String tmpSurName = input.nextLine();
System.out.printf("type first name:");
String tmpFirstName = input.nextLine();
Person tmpP = MainList.FindPerson(tmpSurName, tmpFirstName);
if(!MainList.CheckPerson(tmpP)){
return;
}
System.out.println("");
System.out.printf("confirm the deletion: :\n "+ tmpP + " \nY/N?: ");
do{
option=input.next().charAt(0);
if(option=='N' || option=='n' || option=='N' || option=='v')
break;
else if (option=='Y' || option!='y' || option=='Y' || option!='υ')
MainList.DelPerson(tmpP);
System.out.println("person sucessfully deleted");
}while(option=='N' || option=='n' || option=='N' || option=='v');
}

/**
* adds a new course in the list of courses
* checks: semester number validity, if course exists 
*/

public void AddNewCourse(){
input.nextLine();//clear input buffer
Course c;
System.out.printf("type course ID or course name: ");
String tmpCourseID = input.nextLine();
if(MainList.CheckCourse(tmpCourseID)){
System.out.println("course already exists!");
return;
}
System.out.printf("type course name: ");
String tmpCourseName = input.nextLine();
System.out.printf("type course Semester: ");
int tmpCourseSemester;
do {
while (!input.hasNextInt()) {
System.out.println("Wrong input. Please type a valid semester number!");
input.next();
}
tmpCourseSemester = input.nextInt();
}while (tmpCourseSemester <= 0);
c= new Course(tmpCourseID, tmpCourseName, tmpCourseSemester);
MainList.AddCourse(c);
System.out.println("course sucessfully inserted");
}

/**
* modifies a course's data in the list of courses
* checks: semester number validity, if course exists, confirm modification 
*/

public void ManipulateCourse() {
input.nextLine();//clear input buffer
char option;
System.out.printf("type course ID or course name: ");
String tmpCourseID = input.nextLine();
Course tmpC = MainList.GetCourseByID(tmpCourseID);
if(!MainList.CheckCourse(tmpCourseID)){
System.out.println("no such course exists!");
return;
}
System.out.println("");
System.out.printf ("confirm course modification:\n"+ tmpC + " \nY/N?: ");
do{
option=input.next().charAt(0);
if(option=='N' || option=='n' || option=='N' || option=='v')
break;
else if (option=='Y' || option!='y' || option=='Y' || option!='υ')
{
input.nextLine();//clear input buffer
System.out.printf("type course name: ");
String tmpCourseName = input.nextLine();
tmpC.setCourseName(tmpCourseName);
System.out.printf("type course Semester: ");
int tmpCourseSemester;
do {
while (!input.hasNextInt()) {
System.out.println("Wrong input. Please type a valid semester number!");
input.next();
}
tmpCourseSemester = input.nextInt();
}while (tmpCourseSemester <= 0);
tmpC.setCourseSemester(tmpCourseSemester);
}
System.out.println("");
System.out.printf ("course has been modified :\n"+ tmpC);
}while(option=='N' || option=='n' || option=='N' || option=='v');
}

/**
* deletes a course from the list of courses
* checks: if course exists, confirm deletion 
*/

public void DeleteCourse() {
input.nextLine();//clear input buffer
char option;
System.out.printf("type course ID of course name: to be deleted: ");
String tmpCourseID = input.nextLine();
Course tmpC = MainList.GetCourseByID(tmpCourseID);
if(!MainList.CheckCourse(tmpCourseID)){
System.out.println("no such course exists!");
return;
}
System.out.println("");
System.out.printf("confirm course deletion:\n "+ tmpC + " \nY/N?: ");
do{
option=input.next().charAt(0);
if(option=='N' || option=='n' || option=='N' || option=='v')
break;
else if (option=='Y' || option!='y' || option=='Y' || option!='υ')
MainList.DelCourse(tmpC);
System.out.println("course sucessfully deleted");
}while(option=='N' || option=='n' || option=='N' || option=='v');
}

/**
* assigns a course from the list of courses to persons
* checks: if person exists, if course has already been assigned 
*/

public void AddCourseToPerson() {
input.nextLine();//clear input buffer
System.out.printf("type person's data to be assigned to a course:\n ");
System.out.printf("type surname:");
String tmpSurName = input.nextLine();
System.out.printf("type name:");
String tmpFirstName = input.nextLine();
Person tmpP = MainList.FindPerson(tmpSurName, tmpFirstName);
if(!MainList.CheckPerson(tmpP)){
return;
}
System.out.println("");
System.out.printf("the person is:\n "+ tmpP);
System.out.println("");
System.out.printf("type Course ID or Course Title: ");
String tmpCourseID = input.nextLine();
Course tmpC = MainList.GetCourseByID(tmpCourseID);
if(tmpP.HasCourse(tmpC.getCourseID()))
System.out.println("course already exists!");
else{
tmpP.AddCourse(tmpC);
System.out.println("");
System.out.println("course sucessfully assigned");
}
}

/** 
* deletes a course from a person
* prints a list of assigned courses, choice by course id or course name
* checks:  if person exists, if course has already been assigned, confirm deletion 
*/

public void DeleteCourseFromPerson() {
char option;
input.nextLine();//clear input buffer
System.out.printf("type person's data for course deletions:\n ");
System.out.printf("type surname:");
String tmpSurName = input.nextLine();
System.out.printf("type name:");
String tmpFirstName = input.nextLine();
Person tmpP = MainList.FindPerson(tmpSurName, tmpFirstName);
if(!MainList.CheckPerson(tmpP)){
return;
}
System.out.println("");
System.out.printf("person's data :\n "+ tmpP);
System.out.println("");
System.out.printf("courses assigned to person :\n "+ tmpP.getCourses());
System.out.println("");
System.out.printf("type course ID or course name: ");
String tmpCourseID = input.nextLine();
if(!tmpP.HasCourse(tmpCourseID))
System.out.println("course does not exist!");
else{
System.out.println("");
System.out.printf("\"confirm course deletion :\n "+ MainList.GetCourseByID(tmpCourseID) + " \nY/N?: ");
option=input.next().charAt(0);
if(option=='N' || option=='n' || option=='N' || option=='v')
return;
else if (option=='Y' || option!='y' || option=='Y' || option!='υ') {
tmpP.RemoveCourse(tmpCourseID);
System.out.println("");
System.out.println("course sucessfully deleted!");
}
}
}

/** 
* adds grade to an assigned course to a student
* prints a list of assigned courses, choice by course id 
* checks: valid grade, if course assigned, if course already graded, grade number type validity
*/

public void AddGrade() {
input.nextLine();//clear input buffer
char option;
System.out.printf("type person's data for grading:\n ");
System.out.printf("type surname:");
String tmpSurName = input.nextLine();
System.out.printf("type name:");
String tmpFirstName = input.nextLine();
Person tmpP = MainList.FindPerson(tmpSurName, tmpFirstName);
if(!MainList.CheckPerson(tmpP)){
return;
}
if (tmpP instanceof Student) {
Student tmpS = (Student)tmpP;
System.out.println("courses registerd into:\n "+ tmpP + " \neinai: ");
System.out.println(tmpP.getCourses());
Grade g;
boolean check=false;
double tmpGrade;
do{
String tmpGrade_Student_Id = tmpS.getAM();
System.out.printf("type course ID or course name:");
String tmpGrade_Course_Id = input.nextLine();
if(tmpS.HasCourse(tmpGrade_Course_Id)) {
if(MainList.CheckGrade(tmpGrade_Course_Id)) {
g=MainList.FindGrade(tmpGrade_Course_Id);
System.out.println("grading already exists" + MainList.GetCourseByID(tmpGrade_Course_Id));
System.out.println("grade:" + MainList.FindGrade(tmpGrade_Course_Id));
System.out.printf("confirm grade modification Y/N:");
option=input.next().charAt(0);
if(option=='N' || option=='n' || option=='N' || option=='v')
return;
else if (option=='Y' || option!='y' || option=='Y' || option!='υ'){
System.out.printf("type course grade:");
do {
/*while(!input.hasNextDouble()) {
System.out.println("wrong input! please type valid number type ");
System.out.printf("Dwste apodekti vathmologia : ");
input.next();
} */
tmpGrade = input.nextDouble();
}while (tmpGrade <= 0);
g.setGrade(tmpGrade);
System.out.println("grade sucessfully modified: " + g);
return;
}
}
else{
System.out.printf("type course grade: ");
do {
/*while( !input.hasNextDouble()) {
System.out.println("Aytos den einai swstos vathmos!");
System.out.printf("Dwste apodekti vathmologia: ");
input.next ();
} */
tmpGrade = input.nextDouble();
}while (tmpGrade <= 0 );
try{
g= new Grade(tmpGrade_Student_Id, tmpGrade_Course_Id, tmpGrade);
check=true;
MainList.AddGrade(g);
System.out.println("grade sucessfully inserted :" + g);
}
catch (Exception e) {
System.out.println (e.getMessage());
}
}
}
else
System.out.println("this course has not been assigned to the student! ");
}while (!check);
}
else
System.out.println("no such student exists");
}
/**
 * calculates the average grade of a student
 * checks: if student exists
 * not used
 */

public void AvgofStudent (){
System.out.println("tpye student's data to be searched:\n");
System.out.println("type surname: ");
String tmpSurName = input.nextLine();
System.out.println("type name: ");
String tmpFirstName = input.nextLine();
Person tmpP = MainList.FindPerson (tmpSurName, tmpFirstName);
if (!MainList.CheckPerson(tmpP)){
return;
}
if (tmpP instanceof Student){
Student tmpS= (Student)tmpP;
System.out.println("the average of student:" + tmpS + "\nis: " + (MainList.AVG_Student(tmpS.getStudId())));
}
else
System.out.println("no such student exists!");
}

/**
* calculates the average of all students
* checks: if students list is empty 
*/

public void AvgAllStudents(){
if (MainList.getP_List().isEmpty())
System.out.println("student list is empty!");
else {
System.out.println("average per student: ");
System.out.println("********************");
System.out.println("student_ID surname name average");
for (Person S: MainList.getP_List()){
if (S instanceof Student){
Student tmpS = (Student) S;
System.out.printf("%-6s %-15s %-15s %f\n", tmpS.getStudId(), tmpS.getSurName(), tmpS.getFirstName (), MainList.AVG_Student(tmpS.getStudId()));
}
}
}
System.out.println("");
}

/** 
* average of all courses (per course)
* checks: if list of courses is empty
*/
public void AvgAllCourses(){
if(MainList.getC_List().isEmpty())
System.out.println("list of courses is empty!");
else{
System.out.println("average per course:");
System.out.println("******************");
int i=1;
System.out.println("course average Μ/Ο");
for (Course C: MainList.getC_List()){
System.out.printf("%d %-25s %f\n" , i++, C.getCourseName(), MainList.AVG_Course(C.getCourseID()));
}
}
System.out.println("");
}

/**
* saves persons' data
* lists are saved in desktop
* checks: for read/save of files
*/

public void SaveData(){
String FnC;
boolean Rc;
System.out.println("");
System.out.println("Save course Data");
System.out.println("name of file to be saved: ");
FnC = input.nextLine();
Rc = MainList.SaveCourses (FnC);
if (Rc)
System.out.println("save completed...");
else
System.out.println("save failed...");
String FnP;
boolean Rp;
System.out.println ("");
System.out.println("save professor data");
System.out.print ("name of file to be saved: ");
FnP = input.nextLine();
Rp = MainList.SaveProfessors (FnP);
if (Rp)
System.out.println("save completed...");
else
System.out.println("save failed...");
String FnS;
boolean Rs;
System.out.println ("");
System.out.println("save student data");
System.out.print ("name of file to be saved: ");
FnS = input.nextLine();
Rs = MainList.SaveStudents (FnS);
if (Rs)
System.out.println("save completed..");
else
System.out.println("save failed...");
String FnG;
boolean Rg;
System.out.println ("");
System.out.println("save grade data");
System.out.print ("name of file to be saved:");
FnG = input.nextLine();
Rg = MainList.SaveGrades (FnG);
if (Rg)
System.out.println("save completed..");
else
System.out.println("save failed...");
}

/** 
* loads data of students & professors form desktop
* 4 files must be loaded
* checks: read/save file
*/

public void LoadData (){
String FnC;
boolean Rc;
System.out.println("");
System.out.println("course data loading");
System.out.println("name of file to be loaded:");
FnC = input.nextLine();
Rc = MainList.LoadCourses (FnC);
if (Rc)
System.out.println("loading completed...");
else
System.out.println("loading not completed...");
String FnP;
boolean Rp;
System.out.println("");
System.out.println("professors' data loading");
System.out.println("name of file to be loaded:: ");
FnP = input.nextLine();
Rp = MainList.LoadProfessors (FnP);
if (Rp)
System.out.println("loading completed...");
else
System.out.println("loading not completed...");
String FnS;
boolean Rs;
System.out.println ("");
System.out.println("students's data loading");
System.out.print ("name of file to be loaded: ");
FnS = input.nextLine();
Rs = MainList.LoadStudents (FnS);
if (Rs)
System.out.println("loading completed...");
else
System.out.println("loading not completed...");
String FnG;
boolean Rg;
System.out.println ("");
System.out.println("grade data loading");
System.out.print ("Όname of file to be loaded: ");
FnG = input.nextLine();
Rg = MainList.LoadGrades (FnG);
if (Rg)
System.out.println("loading completed...");
else
System.out.println("loading not completed...");
}

/**
* menu to choose between saving or loading data from application
* checks: valid menu choice (number) 
*/ Μενού επιλογήσς αποθήκευσης ή φόρτωσης των δεδομένων της εφαρμογής

public void LoadSaveDialogue() {
int option;
char choice;
System.out.println("Tyep 1 to save into a file") ;
System.out.println("Type 2 to load from a file");
System.out.printf("Choice: ");
do {
while(!input.hasNextInt()) {
System.out.println ("Wrong input! Please type a valid semester number");	
input.next();
}
option = input.nextInt();
}while (option <= 0 );
input.nextLine(); // clear input buffer
if (option==1) {
SaveData();
}		
else if (option ==2) {
LoadData();
}
else
System.out.println("wrong choice!.");
}

/** 
* pauses program running, until <ENTER> input
*/
public void Pause () {
Scanner K = new Scanner(System.in);
System.out.println("");
System.out.printf("Press ENTER to continue...");
K.nextLine ();
System.out.println ("");
}

}package ex2.ui;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Scanner;

/*import ex2.data.Course;
import ex2.data.Person;
import ex2.data.Professor;
import ex2.data.Student;
import ex2.data.Grade;
*/

/**
* Represents lists of professors, students, grades and courses
*/

public class Lists {
ArrayList <Person> PersonList;
ArrayList <Course> CourseList; 
ArrayList <Grade>  GradeList; 
final String SaveDir = "ΤΟ ΔΙΚΌ ΣΑΣ PATH"; //bale to path edw

public Lists() {
PersonList = new ArrayList(); 
CourseList = new ArrayList(); 
GradeList = new ArrayList();
}

//Getters
public ArrayList <Person> getPersonList () {
return PersonList;
t

public ArrayList<Course> getCourseList () {
return CourseList;
}

public ArrayList <Grade> getGradeList () 
{
return GradeList;
}

/**
* adds a new person to the list of persons
* @param p person to be added
*/

public void AddPerson (Person p) 
{
PersonList.add (p);
}

/**
* adds a new course to the list of courses
* @param c course to be added
*/
public void AddCourse (Course c) 
{
CourseList.add (c);
}

/**
* adds a new grade to the list of grades
* @param c course to be added
*/

public void AddGrade (Grade g)
{
GradeList.add (g);
}

/**
* deletes a person from the list of persons
* @param p person to be searched for
*/

public void DelPerson (Person p) 
{
PersonList.remove (p);
}

/**
* deletes a course from the list of courses
* @param c course to be searched for
*/

public void DelCourse (Course c) 
{
CourseList.remove (c);
}

/**
 * Checks if a course exists in the list of courses
 * Μέθοδος ελέγχου ύπαρξης μαθήματος στη λίστα των μαθημάτων.
 * @param CourseId course's ID number
 * @param CourseName course's name
 * @return true if course exists, false if not
 */
public boolean CheckCourse (String CourseId)
{
for (Course tmp : CourseList)
        {
                if (tmp.getCourseId(). equals(CourseId)  || tmp.getCourseName(). equals(CourseId))
                return true;
        }
return false;
}

/**
* checks if a person exists in the list of persons
* @param p person to be searched for
* @return true if person exists, false if not
*/
public boolean CheckPerson (Person p) {
for (Person tmp: PersonList) 
        {
                if (tmp == p)
                return true;
        }
return false;
}

/**
* checks if a professor exists in the list of persons
* @param ProffesorId professor's ID to be searched for
* @return true if professor exists, false if not
*/

public boolean CheckProfessor (String ProffesorId) 
{
for (Person tmp: PersonList)
        {       if (tmp instanceof Professor && ((Professor) tmp).getProffesorId().equals (ProffesorId))
                return true;
        }
return false;
}

/**
* Checks if a student exists in the list of persons
* @param StudentId student's ID number
* @return true if student exists, false if not
*/

public boolean CheckStudent (String StudentId) {
for (Person tmp: PersonList) 
        {       if (tmp instanceof Student && ((Student) tmp).getStudentId().equals (StudentId))
                return true;
        }
return false;
}

/**
* Checks if a grade exists 
* @param CourseId course's id number
* @return true if grade exists, false if not
*/

public boolean CheckGrade (String CourseId) 
{
for (Grade tmp: GradeList)
        {
                if (tmp.getGrade_Course_Id() . equals (CourseId))
                return true;
        }
return false;
}

/**
* searches for a person in the list of persons
* @param SurName person's surname
* @param FirstName person's first name
* @return true if person exists, null if not
*/

public Person FindPerson (String SurName, String FirstName)
{
for (Person tmp: PersonList) 
        {       if (tmp.getSurName().equals (SurName) && tmp.getFirstName().equals (FirstName))
                return tmp;
        }
System.out.println("No such person exists!");
return null;
}

/**
* searches for a grade in the list of grades
* @param CourseId course's id 
* @return tmp if grade exists, null if not
*/

public Grade FindGrade (String CourseId) 
{
for (Grade tmp: GradeList)
        {
                if (tmp.getGrade_Course_Id().equals(CourseId))
                return tmp;
        }
System.out.println("No such grade exists!");
return null;
}

/**
* Searches for a course in the list of courses
* @param CourseId course's ID number
* @param CourseName course's name
* @return tmp if course found, null if not
*/

public Course FindCourseById (String CourseId) 
{
for (Course tmp: CourseList)
        {
                if (tmp.getCourseId().equals (CourseId) || tmp.getCourseName ().equals(CourseId))
                return tmp;
        }
return null;
}

/**
* calculates the average of a student's grades
* @param StudentId student's ID number
* @return avg the average of a student's grades
*/
public double AVG_Student (String StudentId) 
{
int i=0;
double sum=0;
double avg;

for (Grade tmp: GradeList) 
        {
                if (tmp.getGrade_Student_Id ().equals (StudentId))
                {
                        i++;
                        sum+=tmp.getGrade ();
                }
        }
avg=sum/i;
return avg;
}

/**
* calculates the average of a course's grades
* @param CourseId course's ID number
* @return avg course's average
*/

public double AVG_Course (String CourseId)
{
int i=0;
double sum=0;
double avg;
for (Grade tmp: GradeList)
        {
                if (tmp.getGrade_Course_Id().equals(CourseId))
                {
                        i++;
                        sum+=tmp.getGrade();
                }
        }
avg=sum/i;
return avg;
}

/**
* stores the list of professors in a file
* @param FN name with which the file is gonna be saved
* @return true if saved successfully, false if not
*/

public boolean SaveProfessorsList (String FN) 
{
try
        {
                PrintWriter PF = new PrintWriter (SaveDir + FN + ".csv");
                for (Person tmp: PersonList)
                {
                   if (tmp instanceof Professor)
                   {
                        Professor P = (Professor) tmp;
                        StringBuilder SB = new StringBuilder ();
                        SB.append (P.getProffesorId())
                        .append (';')
                        .append (P.SurName)
                        .append (';')
                        .append (P.FirstName)
                        .append (';')
                        .append (P.Email)
                        .append (';')
                        .append (P.Phone)
                        .append (';')
                        .append (P.getExpertise())
                        .append (';')
                        .append (P.GetCoursesNames());
                        String Tbr = SB.toString();
                        PF.println (Tbr);
                   }
                }
        PF.close();
        } catch (FileNotFoundException e)
                {
                System.out.println ("ACHTUNG:" + e.getMessage () + "!!!");
                return false;
        }
return true;
}

/**
* stores the list of students in a file
* Μέθοδος αποθήκευσης της λίστας των φοιτητών σε αρχείο.
* @param FN name with which the file is gonna be saved
* @return true if saved successfully, false if not
*/

public boolean SaveStudentsList (String FN) 
{
try
        {
                PrintWriter St = new PrintWriter (SaveDir + FN + ".csv");
                for (Person tmp: PersonList) 
                {
                        if (tmp instanceof Student)
                        {
                        Student S = (Student) tmp;
                        StringBuilder SB = new StringBuilder ();
                        SB.append (S.getAM())
                        .append (';')
                        .append (S.SurName)
                        .append (';')
                        .append (S.FirstName)
                        .append (';')
                        .append (S.Email)
                        .append (';')
                        .append (S.Phone)
                        .append (';')
                        .append (S.getSemester())
                        .append (';')
                        .append (S.GetCoursesNames());
                        String Tbr = SB.toString();
                        St.println (Tbr);
                        }
                }
                St.close ();
        } catch (FileNotFoundException e)
                {
                System.out.println ("ACHTUNG:" + e.getMessage () + "!!!");
                return false;
                }
return true;
}

/**
* stores the list of courses in a file
* @param FN name with which the file is gonna be saved
* @return true if saved successfully, false if not
*/
public boolean SaveCoursesList (String FN) 
{
try
        {
                PrintWriter Cr = new PrintWriter (SaveDir + FN + ".csv");
                for (Course tmp: CourseList)
                {
                        StringBuilder SB = new StringBuilder ();
                        SB.append (tmp.getCourseId())
                        .append (';')
                        .append (tmp.getCourseName())
                        .append (';')
                        .append (tmp.getCourseSemester());
                        String Tbr = SB.toString();
                        Cr.println (Tbr);
                }
                Cr.close ();
        } catch (FileNotFoundException e)
                {
                System.out.println ("ACHTUNG:" + e.getMessage () + "!!!");
                return false;
                }
return true;
}

/**
* stores the list of grades in a file
* @param FN name with which the file is gonna be saved
* @return true if saved successfully, false if not
*/

public boolean SaveGradesList (String FN) 
{
try
        {
                PrintWriter Gr = new PrintWriter (SaveDir + FN + ".csv");
                for (Grade tmp: GradeList)
                {
                StringBuilder SB = new StringBuilder ();
                SB.append (tmp.getGrade_Student_Id())
                .append (';')
                .append (tmp.getGrade_Course_Id())
                .append (';')
                .append (tmp.getGrade());
                String Tbr = SB.toString();
                Gr.println (Tbr);
                }
                Gr.close ();
        } catch (FileNotFoundException e)
                {
                System.out.println ("ACHTUNG:" + e.getMessage () + "!!!");
                return false;
        }
return true;
}


/**
* loads the professors' list from a file
* @param FN name of the file to be accessed
* @return true if loaded successfully, false if not
*/

public boolean LoadProfessorsList (String FN)
{
boolean cool = false;
//erase the pre-loaded entries
        ArrayList <Person> TmpList = new ArrayList ();
        for (Person tmp: PersonList) 
        {
        if (tmp instanceof Professor)
        TmpList.add (tmp);
        }
        PersonList.removeAll (TmpList);
        TmpLitt = null;
//end
try {
        FileInputStream fs = new FileInputStream (SaveDir + FN + ".csv");
        BufferedReader br = new BufferedReader (new InputStreamReader (fs));
        String StrLine;
        while ((StrLine = br.readLine()) != null)
        {
        String[] Parts = StrLine.split (";");
        Professor Pr = new Professor (Parts [0], Parts [1], Parts [2], Parts [3], Parts [4], Parts [5]);
        PersonList.add(Pr);t
                if (Parts.length>6) 
                {
                ArrayList <Course> tmpCList = new ArrayList ();
                String [] tmpCourse = Parts[6].split (",");
                for (int i=0; i<tmpCourse.length; i++)
                        {
                        Course tmpC= new Course (null);
                        tmpC.setCourseName (tmpCourse [i]);
                        for (int j=0; j<CourseList.size(); j++)
                                {
                                if(tmpC.getCourseName().equals(CourseList.get(j).getCourseName()))
                                tmpCList.add(CourseList.get(j));
                                }
                        }
                Pr.setCourses (tmpCList);
                }
                else
                Pr.setCourses (null);
        }
fs.close();
cool = true;
} catch (FileNotFoundException e) 
        {
        System.out.println ("Cannot access file" + SaveDir + FN);
        }
  catch (IOException e) 
        {
        e.printStackTrace (); //prints the exceptions with additional info (class-line of error etc.)
        } 
return cool;
}

/**
* loads the students' list from a file
* @param FN name of the file to be accessed
* @return true if loaded successfully, false if not
*/

public boolean LoadStudentsList (String FN)
{
boolean cool = false;

//erase the pre-loaded entries
ArrayList <Person> TmpList = new ArrayList ();
for (Person tmp: PersonList) 
        {if (tmp instanceof Student)
        TmpList.add (tmp);
        }       
PersonList.removeAll (TmpList);
TmpLitt = null;
//end
try
        {
        FileInputStream fs = new FileInputStream (SaveDir + FN + ".csv");
        BufferedReader br = new BufferedReader (new InputStreamReader (fs));
        String StrLine;
        while ((StrLine = br.readLine()) != null)
                {
                String[] Parts = StrLine.split (";");
                Student St = new Student (Parts [0], Parts [1], Parts [2], Parts [3], Parts [4], Integer.parseInt(Parts [5]));
                PersonList.add(St);t
                if (Parts.length>6) 
                        {
                        ArrayList <Course> tmpCList = new ArrayList ();
                        String [] tmpCourse = Parts[6].split (",");
                        for (int i=0; i<tmpCourse.length; i++)
                                {
                                Course tmpC= new Course (null);
                                tmpC.setCourseName (tmpCourse [i]);
                                        for (int j=0; j<CourseList.size(); j++)
                                        {
                                        if(tmpC.getCourseName().equals(CourseList.get(j).getCourseName()))
                                        tmpCList.add(CourseList.get(j));
                                        }
                                }
                        St.setCourses (tmpCList);
                        }
                else
                St.setCourses (null);
                }
        fs.close();
        cool = true;
        } catch (FileNotFoundException e) 
        {
        System.out.println ("Cannot access file" + SaveDir + FN);
        }
          catch (IOException e) 
        {
        e.printStackTrace (); //prints the exceptions with additional info (class-line of error etc.)
        } 
return cool;
}

/**
* loads the courses' list from a file
* @param FN name of the file to be accessed
* @return true if loaded successfully, false if not
*/

public boolean LoadCoursesList (String FN)
{
boolean cool = false;

//erase the pre-loaded entries
ArrayList <Course> TmpList = new ArrayList ();
for (Course tmp: CourseList)
        {
        TmpList.add (tmp);
        }
CourseList.removeAll (TmpList);
TmpList = null;
//end
try
        {
        FileInputStream fs = new FileInputStream (SaveDir + FN + ".csv");
        BufferedReader br = new BufferedReader (new InputStreamReader (fs));
        String StrLine;
        while ((StrLine = br.readLine()) != null)
                {
                String [] Parts = StrLine.split (";");
                Course Co = new Course (Parts [0], Parts [1], Integer.parseInt(Parts [2]));
                CourseList.add(Co);
                }
        fs.close();
        cool = true;
        } catch (FileNotFoundException e) 
        {
        System.out.println ("Cannot access file" + SaveDir + FN);
        }
          catch (IOException e) 
          {
           e.printStackTrace (); //Τυπώνει τα exceptions μαζί με πληροφορίες όπως η γραμμή και η κλασή στην οποία
          } 
return cool;
}


/**
* loads the grades' list from a file
* @param FN name of the file to be accessed
* @return true if loaded successfully, false if not
*/

public boolean LoadGradeList (String FN) 
{
boolean cool = false;

//erase the pre-loaded entries
ArrayList <Grade> TmpList = new ArrayList ();
for (Grade tmp: GradeList)
        {
        TmpList.add (tmp);
        }
GradeList.removeAll (TmpList);
TmpList = null;
//end
try
        {
        FileInputStream fs = new FileInputStream (SaveDir + FN + ".csv");
        BufferedReader br = new BufferedReader (new InputStreamReader (fs));
        String StrLine;
        while ((StrLine = br.readLine()) != null)
                {
                String[] Parts = StrLine.split (";");
                Grade Gr = new Grade (Parts [0], Parts [1], Double.parseDouble(Parts [2]));
                GradeList.add(Gr);
                }
        fs.close();
        cool = true;
        } catch (FileNotFoundException e) 
          {
          System.out.println ("Δεν μπορεί να διαβαστεί το αρχείο" + SaveDir + FN);
          }
          catch (IOException e) 
          {
          e.printStackTrace (); 
          }
          catch (Exception e)
          {
          System.out.println (e.getMessage());
          }
return cool;
}

} //end













package ex2.data;

/**
 *Η κλάση Grade παριστά την βαθμολογία σε ένα μάθημα του προγράμματος σπουδών ενός φοιτητή. 
 * Αφορά σε ένα άτομο και περιλαμβάνει τα κοινά στοιχεία φοιτητών και καθηγητών,
 * τα οποία και κληρονομούνται από τις αντιστοιχες κλασεις.
 * @author Ioulia Anastasiou, Iraklis Lefas, Alexandros Feidis
 */

public class Grade
{
    private String Grade_StudId;
    private String Grade_CourseId;
    private double Grade;
    
    //constructor
    public Grade (String Grade_StudId, String Grade_CourseId, double Grade) throws Exception
    {     
        this.Grade_StudId= Grade_StudId;
        this.Grade_CourseId = Grade_CourseId;
        if (Grade<0||Grade>10.0)
        {
          throw new Exception("Grade must be between 0 and 10"); //des na bei loop gia try again
        }
     this.Grade=Grade;
    }

    //Getters and Setters
    public String getGrade_StudId ()
    {
        return Grade_StudId;
    }

    public void setGrade_StudId (String Grade_StudId)
    {
        this.Grade_StudId= Grade_StudId;
    }

    public String getGrade_CourseId()
    {
        return Grade_CourseId;
    }

    public void setGrade_CourseId (String Grade_CourseId)
    {
        this.Grade_CourseId= Grade_CourseId;
    }

     public double getGrade ()
    {
        return Grade;
    }
    public void setGrade (double Grade)
    {
        this.Grade= Grade;
    }

    /**
     * shows all grades for a student
     */
    public void ShowAll()
    {
    System.out.println("Student's Id...........:" + Grade_StudId);
    System.out.println("Course.................:" + Grade_CourseId);
    System.out.println("Student's Grade........:" + Grade);
    }

    /**
     * returns all student's grades data in one string
     *@return a string with all student's grades data, with additional data about the student's grades
    */
    @Override
    public String toString()
    {
        String OneString;
        OneString = Grade_StudId + " / " + Grade_CourseId + " / " + Grade ;
        //OneString = super.toString() + "  /  " + StudId + "  /  " + Semester; 
        return OneString;
    }
}






package ex2.data;

/**
 * Η κλάση Course παριστά ένα μάθημα του προγράμματος σπουδών. Παρόλο που 
 * είναι "κακός σχεδιασμός" τα χαρακτηριστικά της κλάσης είναι
 * ορισμένα χωρίς προσδιοριστή πρόσβασης, άρα είναι προσβάσιμα άμεσα μόνο 
 * από τις κλάσεις που βρίσκονται στο ίδιο πακέτο και συγκεκριμένα
 * από τις {@link Professor} και {@link Student}. Φυσικά υπάρχουν οι 
 * κατάλληλοι getters για πρόσβαση από τις κλάσεις των υπολοίπων πακέτων.
 *
 * @author Ioulia Anastasiou, Iraklis Lefas, Alexandros Feidis
 */
public class Course
{

    private String CourseId;
    private String CourseName;
    private int CourseSemester;

    // constructors
    /**
     * 
     * @param CourseId :course ID
     * @param CourseName :course name
     * @param CourseSemester :course's semester
     */

    public Course (String I, String N, int Sem)
    {
        this.CourseId = I;      //na dokimasw kai CourseId=I
        this.CourseName = N;
        this.CourseSemester = Sem;
    }

    // getters & setters

    public String getCourseId ()
    {
        return CourseId;
    }

    public void setCourseId (String CourseId)
    {
        this.CourseId = CourseId;
    }
    
    public String getCourseName ()
    {
        return CourseName;
    }

    public void setCourseName (String CourseName)
    {
        this.CourseName = CourseName;
    }

    public int getCourseSemester ()
    {
        return CourseSemester;
    }

    public void setCourseSemester (int CourseSemester)
    {
        this.CourseSemester = CourseSemester;
    }
    
    /**
     * returns course's data
     */
    public void ShowAll()
    {
     System.out.println ("COURSE DATA");        
     System.out.println ("==================");   
     System.out.println ("Course ID : " + CourseId);
     System.out.println ("Course Name : " + CourseName);
     System.out.println ("Course Semester : " + CourseSemester);
    }

    /**
     * returns all data in one string
    */
    
    @Override
    public String toString ()
    {
        String OneString;
        OneString = CourseID + " / " + CourseName + " / " + CourseSemester;
        return OneString;
        //return ID + " - " + Name + " - " + Semester;
    }

}