I have written this code:
public class ArraLists {
public static void main(String[] args) {
ArrayList<Amphitheater> amphitheaters= new ArrayList<Amphitheater>();
Amphitheater a1 = new Amphitheater("Amph 2");
Amphitheater a2 = new Amphitheater("Amph 3");
Amphitheater a3 = new Amphitheater("Amph 8");
Amphitheater a4 = new Amphitheater("Amph 9");
Amphitheater a5 = new Amphitheater("Amph 11");
Amphitheater a6 = new Amphitheater("Amph 10");
Amphitheater a7 = new Amphitheater("Amph 12");
Amphitheater a8 = new Amphitheater("Amph 13");
Course cC1 = new Course("Math","M123");
amphitheaters.add(a1);
amphitheaters.add(a2);
amphitheaters.add(a3);
amphitheaters.add(a4);
amphitheaters.add(a5);
amphitheaters.add(a6);
amphitheaters.add(a7);
amphitheaters.add(a8);
DateExamination d1= new DateExamination("03 May",amphitheaters);
DateExamination d2= new DateExamination("04 May",amphitheaters);
ArrayList<Amphitheater> amph1= d1.getAmphitheaters();
ArrayList<Amphitheater> amph2= d2.getAmphitheaters();
amph2.get(1).addCourse(1,cC1);
System.out.println("Amphitheaters of D1");
for(Amphitheater a: amph1) {
System.out.println(a.getName());
System.out.println(a.getAvailableHours());
}
System.out.println("Amphitheaters of D2");
for(Amphitheater a: amph2) {
System.out.println(a.getName());
System.out.println(a.getAvailableHours());
}
System.out.println("\n\nList of Amphitheaters that I created in Main.");
for(Amphitheater a: amphitheaters) {
System.out.println(a.getName());
System.out.println(a.getAvailableHours());
}
}
}
public class Course {
private String name;
private String id;
private ArrayList<Amphitheater> amphitheaters= new ArrayList<Amphitheater>();
private ArrayList<Integer> hours= new ArrayList<Integer>();
public Course(String name, String id){
this.name=name;
this.id=id;
}
public void addAmphitheater(Amphitheater amphitheater,int hour){
amphitheaters.add(amphitheater);
hours.add(hour);
}
}
public class Amphitheater{
private String name;
private HashMap<Integer,Boolean> availableHours=new HashMap<Integer,Boolean>(); //Hour,Available
private HashMap<Integer,Course> courses= new HashMap<Integer,Course>(); //Hour,Course
public Amphitheater(String name){
this.name=name;
for(int i=0; i<5; i++){
availableHours.put(i,true);
courses.put(i,null);
}
}
public boolean isHourAvailable(Integer hour){
return availableHours.get(hour);
}
public ArrayList<Integer> getAvailableHours(){
ArrayList<Integer> avHours= new ArrayList<Integer>();
for(int i=0; i<5; i++){
if(availableHours.get(i))
avHours.add(i);
}
return avHours;
}
public void addCourse(Integer hour,Course course){
courses.put(hour,course);
availableHours.put(hour, false);
course.addAmphitheater(this,hour);
}
public void setName(String name){
this.name=name;
}
public String getName(){
return name;
}
}
public class DateExamination{
private ArrayList<Amphitheater> amphitheaters;
private String name;
public DateExamination(String name,ArrayList<Amphitheater> amphitheaters) {
this.name=name;
this.amphitheaters=amphitheaters;
}
public ArrayList<Amphitheater> getAmphitheaters(){
return amphitheaters;
}
}
I pass as an argument to DateExamination objects the ArrayList with amphitheaters.
The problem is, when I change a value to the amphitheaters of d1 (DateExamination), automatically the same value is changed to the amphitheaters of d2 (DateExamination).
Also, the ArrayList that I created in Main is changed. I think that all the ArrayList's has references to the same objects, but I really can't understand.
I want each object of DateExamination has an ArrayList of amphitheaters which will be independent of the others amphitheaters.
I also tried to pass as an argument a .clone() of this ArrayList but has no result.
