copying objects with data fields

Question

I need to copy all content of class object to new class object. I don't need to copy references to data, because in that case if I change fields in object a2 those data will be changed in object a2.

public class Msg {
    String info="";
    HashMap fld = new HashMap();

    public void assign(Msg value) {
        info = value.infol;
        fld = value.fld;
    }

}

// Do stuff with class
a1 = new Msg();
a1.info="111";
a1.fld.put("1","111");

a2 = new Msg();
a2.assign(a1);

How to realise function assign?

Please respect [Java naming conventions](http://www.oracle.com/technetwork/java/javase/documentation/codeconventions-135099.html#367). It helps other understand your code. — Étienne Miret, Aug 08 '13 at 12:48

score 0 · Accepted Answer · answered Aug 08 '13 at 12:35

0

You need to make a copy of your HashMap as well or you will have 2 objects pointing to the same HashMap.

public void Assign(Msg value)
{
    Info = value.Infol;
    fld = new HashMap(value.fld);
}

answered Aug 08 '13 at 12:35

Kevin DiTraglia

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score 0 · Answer 2 · edited Aug 08 '13 at 12:50

0

org.apache.commons.beanutils.PropertyUtils.copyProperties( dest, source );

edited Aug 08 '13 at 12:50

Rohit Jain

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answered Aug 08 '13 at 12:41

Prabhakaran Ramaswamy

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copying objects with data fields

2 Answers2