about many to many relationship?
could you help check this code.
why IT2399/3A & IT2399/3B same answer of lecturer name? it may be opposite.
Code:
import java.util.*;
class Course
{
String CourseName;
int NumberOfStudetn;
Vector activity;
public Course(String CourseName, int NumberOfStudetn){
this.CourseName = CourseName;
this.NumberOfStudetn = NumberOfStudetn;
activity = new Vector();
}
public void addActivity(Activity act){
activity.add(act);
}
public Enumeration getModule() {
Vector module = new Vector();
for (int i = 0; i < activity.size(); i++){
module.add(((Activity) activity.elementAt(i)).getModule());
}
return module.elements();
}
}
class Lecturer
{
String FirstName;
String LastName;
Vector activity;
public Lecturer(String fn, String ln){
FirstName = fn;
LastName = ln;
activity = new Vector();
}
public void addActivity(Activity act){
activity.add(act);
}
public Enumeration getModule() {
Vector module = new Vector();
for (int i = 0; i < activity.size(); i++){
module.add(((Activity) activity.elementAt(i)).getModule());
}
return module.elements();
}
}
class Module
{
String ModuleName;
int LectureTime;
int TutorialTime;
Vector activity;
public Module(String ModuleName, int LectureTime, int TutorialTime){
this.ModuleName = ModuleName;
this.LectureTime = LectureTime;
this.TutorialTime = TutorialTime;
activity = new Vector();
}
public void addActivity(Activity act){
activity.add(act);
}
public Enumeration getCourse() {
Vector course = new Vector();
for (int i = 0; i < activity.size(); i++){
course.add(((Activity) activity.elementAt(i)).getCourse());
}
return course.elements();
}
public Enumeration getLecturer() {
Vector lecturer = new Vector();
for (int i = 0; i < activity.size(); i++){
lecturer.add(((Activity) activity.elementAt(i)).getLecturer());
}
return lecturer.elements();
}
}
class Activity
{
Course course;
Module module;
Lecturer lecturer;
public Activity(Course c, Module m, Lecturer l){
course = c;
module = m;
lecturer = l;
}
static public void CreateActivity(Course c, Module m, Lecturer l){
Activity act = new Activity(c, m, l);
c.addActivity(act);
m.addActivity(act);
l.addActivity(act);
}
public Module getModule(){
return module;
}
public Course getCourse(){
return course;
}
public Lecturer getLecturer(){
return lecturer;
}
}
public class Main_Org {
public static void main(String argv[]) {
String courseNames[] = {"IT2399/3A", "IT2399/3B", "IT2399/1A", "IT2399/1B", "IT2399/2A"};
String ModuleNames[] = {"J2ME", "J2SE", "ABAP", "C#", "VB"};
String LecturerNames[] = {"Peter", "Jason", "Tom", "Jack", "Mark"};
Course courses[] = new Course[5];
Module modules[] = new Module[5];
Lecturer lecturers[] = new Lecturer[LecturerNames.length];
for (int i = 0; i < 5; i++) {
courses[i] = new Course(courseNames[i], 30);
modules[i] = new Module(ModuleNames[i], 1, 2);
lecturers[i] = new Lecturer(LecturerNames[i], LecturerNames[i]);
}
Activity.CreateActivity(courses[0], modules[0], lecturers[3]);
Activity.CreateActivity(courses[0], modules[1], lecturers[1]);
Activity.CreateActivity(courses[0], modules[2], lecturers[2]);
Activity.CreateActivity(courses[0], modules[3], lecturers[3]);
Activity.CreateActivity(courses[0], modules[4], lecturers[4]);
Activity.CreateActivity(courses[1], modules[0], lecturers[4]);
Activity.CreateActivity(courses[1], modules[1], lecturers[3]);
Activity.CreateActivity(courses[1], modules[2], lecturers[2]);
Activity.CreateActivity(courses[1], modules[3], lecturers[1]);
Activity.CreateActivity(courses[1], modules[4], lecturers[0]);
for (int i = 0; i < courses.length; i++ )
{
Enumeration e = courses[i].getModule();
while (e.hasMoreElements())
{
Module mod = (Module)e.nextElement();
String name = ((Lecturer)(mod.getLecturer().nextElement())).FirstName; // why IT2399/3A & IT2399/3B same answer of lecturer name. it may be opposite.
System.out.println(courses[i].CourseName + ": " + mod.ModuleName + " teach by " + name );
}
System.out.println();
}
}
}
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