Deep clone an object in java

Question

Possible Duplicate:
Java: recommended solution for deep cloning/copying an instance

I have an object which has to be cloned. However while cloning it should also clone the objects inside it. How is this possible ??

Answer 1

You must be aware that this is not a well-defined problem and deep-copying cannot be properly done in a mechanized, fully automatic way. These are some of the options:

• Java has the clone protocol, but it's considered deprecated for most scenarios nowadays;
• you can use serialization to serialize-deserialize in-memory;
• you can write so-called copy constructors.

Answer 2

Java Deep-Cloning library The cloning library is a small, open source java library which deep-clones objects. The objects don't have to implement the Cloneable interface. Effectivelly, this library can clone ANY java objects.

Cloner cloner = new Cloner();
MyClass clone = cloner.deepClone(o);

So and here is example cloning.

Answer 3

You need to override clone() method as such

public class Person implements Cloneable{
 private Long id;
 private Address address

  @Override
  protected Object clone() throws CloneNotSupportedException {
  //do deep cloning
  }

 }

Also See

• Proper way to deep copy with copy constructor instead of Object.clone

Answer 4

The simplest way to implement a deep copy is to serialize and then deserialize the object. Look up ObjectInputStream and ObjectOutputStream.

Answer 5

The simplest approach to deep cloning is to use Java serialization, where you serialize and deserialize the object and return the deserialized version.

Answer 6

Another way of cloning is to provide a copy constructor to construct a new instance based on the data of the provided instance:

public MyClass(MyClass instanceToCopy)
{
   ...
}