Creating new array

Question

The question is very simple. Is any simple and fast way to create new (new references) array or it has to be done manually?

Example:

Collection<A> c = new ArrayList<A>();
c.add(new A());
c.add(new A());
c.add(new A());

A[] a1 = c.toArray(new A[0]);
System.out.println("a1: " + Arrays.toString(a1));
System.out.println("c: " + c);

A[] a2 = Arrays.copyOf(a1, a1.length);
System.out.println("a2: " + Arrays.toString(a2));

All created arrays has the same references. I want array with new elements with the same content as old elements. Copies of old elements.

Answer is: How do you make a deep copy of an object in Java? . Now I see that this question is duplicate.

Not sure if I understand the question: do you mean you want a deep copy instead of a shallow copy? — jlordo, Sep 02 '13 at 16:20
Is this a shallow clone (in which just the collection is new) or a deep clone (in which the actual objects in the collection are copied — Richard Tingle, Sep 02 '13 at 16:21
Deep copies are expensive. Generally I write code so I never need to do that. — Peter Lawrey, Sep 02 '13 at 16:24
Please check if this helps you out: http://javatechniques.com/blog/faster-deep-copies-of-java-objects/ got from: http://stackoverflow.com/questions/64036/how-do-you-make-a-deep-copy-of-an-object-in-java — Natan Streppel, Sep 02 '13 at 16:26

score 1 · Accepted Answer · edited May 23 '17 at 10:25

If you want to create a deep copy of the array (meaning: with freshly created references to each of its elements), there are several alternatives, including:

Serialize/deserialize the array (see Apache's SerializationUtils)
Manually copying each element (and that element's attributes, recursively)
Using reflection explicitly
Using a copy constructor

... And so on. Look in stack overflow, there are several posts discussing the subject.

Creating new array

1 Answers1