Question

I need to deep clone these 4 classes, using the cloneable interface. This is my code so far. Is it correct or do I need to make any changes?

class Record implements Cloneable {

private String CNAME;
private ArrayList<Subject> eCores;
private Major eMajor;
private ArrayList<Subject> eElectives;
private int totalCredit;
private Status status;
private ArrayList<Student> students;

@Override
protected Record clone() throws CloneNotSupportedException {
Record record = (Record) super.clone();
record.eMajor = (Major) eMajor.clone();
eCores = new ArrayList<>();
for (Subject s : eCores) {
Subject s1 = (Subject) s.clone();
record.eCores.add(s1);
}
eElectives = new ArrayList<>();
for (Subject ss : eElectives) {
Subject ss1 = (Subject) ss.clone();
record.eElectives.add(ss1);
}
return record;
}

public class Subject implements Cloneable {

private String subjectName;
private String subjectCode;
private int subjectCreditPoint;
private ArrayList<Student> studentList;

@Override
protected Subject clone() throws CloneNotSupportedException {
return (Subject) super.clone();
}

abstract class Student implements Cloneable, Enrollment {

private String studentName;
private String studentDOB;
private String studentSex;//Student Gender
private int studentNumber;
private ArrayList<Record> record;

@Override
protected Student clone() throws CloneNotSupportedException {
Student student = (Student) super.clone();
record = new ArrayList<>();
for (Record r : record) {
Record r1 = (Record) r.clone();
student.record.add(r1);
}
return student;

}

class Major implements Cloneable {

private String mName;
private ArrayList<Subject> mCores;
@Override
protected Major clone() throws CloneNotSupportedException {
Major major = (Major) super.clone();
mCores = new ArrayList<>();
for (Subject s : mCores) {
Subject s1 = (Subject) s.clone();
major.mCores.add(s1);
}
return major;
}

Answer 1

/******************* Record.java *********************/

import java.util.ArrayList;

class Record implements Cloneable {

   private String CNAME;
   private ArrayList<Subject> eCores;
   private Major eMajor;
   private ArrayList<Subject> eElectives;
   private int totalCredit;
   private Status status;
   private ArrayList<Student> students;

   public Record() {

   }

   public Record(String cNAME, ArrayList<Subject> eCores, Major eMajor, ArrayList<Subject> eElectives, int totalCredit,
           Status status, ArrayList<Student> students) {
       super();
       CNAME = cNAME;
       this.eCores = eCores;
       this.eMajor = eMajor;
       this.eElectives = eElectives;
       this.totalCredit = totalCredit;
       this.status = status;
       this.students = students;
   }

   @Override
   public Record clone() {
       Record record = null;
       try {
           record = (Record) super.clone();
       } catch (CloneNotSupportedException cne) {
           record = new Record();
           record.CNAME = this.CNAME;
           record.eCores = new ArrayList<>();
           for (Subject s : this.eCores) {
               Subject s1 = s.clone();
               record.eCores.add(s1);
           }
           record.eMajor = this.eMajor.clone();
           record.eElectives = new ArrayList<>();
           for (Subject ss : this.eElectives) {
               Subject ss1 = ss.clone();
               record.eElectives.add(ss1);
           }
           record.status = this.status;
           record.students = new ArrayList<>();
           for (Student stud : this.students) {
               Student s = stud.clone();
               record.students.add(s);
           }
       }
       return record;
   }

}

/********************* Subject.java ****************/

import java.util.ArrayList;

public class Subject implements Cloneable {

   private String subjectName;
   private String subjectCode;
   private int subjectCreditPoint;
   private ArrayList<Student> studentList;

   @Override
   public Subject clone() {
       Subject subject = null;
       try {
           subject = (Subject) super.clone();
       } catch (CloneNotSupportedException nse) {
           subject.subjectName = this.subjectName;
           subject.subjectCode = this.subjectCode;
           subject.subjectCreditPoint = this.subjectCreditPoint;
           subject.studentList = new ArrayList<>();
           for (Student s : this.studentList) {
               Student stud = s.clone();
               subject.studentList.add(stud);
           }
       }
       return subject;
   }
}

/******************* Student.java *******************/

import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;

public abstract class Student implements Cloneable {

   private String studentName;
   private String studentDOB;
   private String studentSex;
   private int studentNumber;
   private ArrayList<Record> record;

   public Student() {

   }

   public Student(String studentName, String studentDOB, String studentSex, int studentNumber,
           ArrayList<Record> record) {
       super();
       this.studentName = studentName;
       this.studentDOB = studentDOB;
       this.studentSex = studentSex;
       this.studentNumber = studentNumber;
       this.record = record;
   }

   @Override
   public Student clone() {
       Student student = null;
       try {
           student = getClass().getDeclaredConstructor().newInstance();
       } catch (InstantiationException | IllegalAccessException | IllegalArgumentException | SecurityException
               | NoSuchMethodException | InvocationTargetException e) {
           e.printStackTrace();
       }
       student.studentName = this.studentName;
       student.studentDOB = this.studentDOB;
       student.studentSex = this.studentSex;
       student.studentNumber = this.studentNumber;
       student.record = new ArrayList<>();
       for (Record r : this.record) {
           Record r1 = r.clone();
           student.record.add(r1);
       }
       return student;
   }
}

/***************   Major.java *******************/

import java.util.ArrayList;

public class Major implements Cloneable {

   private String mName;
   private ArrayList<Subject> mCores;

   @Override
   public Major clone() {
       Major major = null;
       try {
           major = (Major) super.clone();
       } catch (CloneNotSupportedException nse) {
           major.mName = this.mName;
           mCores = new ArrayList<>();
           for (Subject s : this.mCores) {
               Subject s1 = s.clone();
               major.mCores.add(s1);
           }
       }
       return major;
   }
}