Overriding cloned object completely in java

Question

I'm cloning one object into another object and then trying to change only two parameters in new object. But still the original object is getting changed. I just want both copies should be separate. Here is my code

Subgroup sg1 = new Subgroup();
sg1.setFname("Vali");
sg1.setMname("Sheik");
sg1.setLname("Sha");
Group g1 = new Group();
g1.setSg(sg1);
try { 
     Group g2 = (Group) g1.clone();
     Subgroup sg1 = g2.getSg();
     sg2.setFname("parvez");
     sg2.setMname("syed");
     sg2.setLname("khan");
     g2.setSg(sg2);
     System.out.println(g1);
     System.out.println(g2);
} catch (CloneNotSupportedException e) {  
     e.printStackTrace();
}

Both cases it's printing first object only.

Clone method in group class

 Protected Object clone() throws CloneNotSupportedException {
     return super.clone();
 }

Please add the source code of your classes (Group and Subgroup) — , Sep 26 '16 at 05:19
@RC it's just setters and getters. I'm using my mobile to post the question. — Syed, Sep 26 '16 at 05:26
see https://stackoverflow.com/questions/64036/how-do-you-make-a-deep-copy-of-an-object-in-java?rq=1 — , Sep 26 '16 at 05:26

score 1 · Answer 1 · edited May 23 '17 at 10:34

1

The clone() in class Object does only shallow copy, instead you need to check how to do deep cloning

edited May 23 '17 at 10:34

Community

1
1

answered Sep 26 '16 at 05:27

ravthiru

8,878
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You can use commons-lang SerializationUtils , Group g2 = (Group) SerializationUtils.serialize(g1); But all classes should be Serializable – ravthiru Sep 26 '16 at 05:33

Amit Bhoraniya · Accepted Answer · 2016-09-26T05:50:23.717

By overriding cloning method you will create a copy of your object.

Please find below example:

Subgroup.java

public class Subgroup {

    private String fname;
    private String mname;
    private String lname;

    //getter-setter

    @Override
    protected Object clone() throws CloneNotSupportedException {
        Subgroup sg = new Subgroup();
        sg.setFname(this.fname);
        sg.setMname(this.mname);
        sg.setLname(this.lname);
        return sg;
    }

     //to-string

}

Group.java

public class Group {

    private Subgroup sg;

    //getter-setter

    public Object clone() throws CloneNotSupportedException {
        Group g = new Group();
        g.setSg((Subgroup) this.sg.clone());
        return g;
    }
    //to-string

}

TestMain.java

public class TestMain {

    public static void main(String[] args) {
        Subgroup sg1 = new Subgroup();
        sg1.setFname("Vali");
        sg1.setMname("Sheik");
        sg1.setLname("Sha");
        Group g1 = new Group();
        g1.setSg(sg1);
        try {
            Group g2 = (Group) g1.clone();
            Subgroup sg2 = g2.getSg();
            sg2.setFname("parvez");
            sg2.setMname("syed");
            sg2.setLname("khan");
            g2.setSg(sg2);
            System.out.println(g1);
            System.out.println(g2);
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
    }
}

Overriding cloned object completely in java

2 Answers2