Shallow copy and serialization of Java deep copy

One, shallow copy, deep copy

A shallow copy copies a member variable in an object: if it is a basic type, the copy is the value of the base type, and if the property is a memory address (reference type), the memory address is copied;

Deep Copy, in addition to the basic type, the object referenced by the reference type is also copied, (the referenced object only requires a shallow copy; to make a deep copy, it is generally possible to use serialization and deserialization, or you can manually implement a deep copy of the reference object at all levels)

　　

Second, realize:

Shallow copy: Implement Cloneable interface, rewrite Clone () method, Call parent class Super.clone () in Clone ().

Deep copy: 1. Implement the Cloneable interface, in addition to calling Super.clone (), and manually calling its clone () method on the reference type and assigning values;

2. Using serialization to achieve deep copy, implement Serializable interface, there is no need to rewrite the method;

Serialization can be combined with these two methods:

// when the object is serialized, if this method is implemented, the call Private void throws ioexception{    stream.defaultwriteobject ();    Stream.writeobject (custom object);} // when the object is deserialized, if this method is implemented, the call Private void throws ioexception{    stream.defaultreadobject ();    Stream.readobject ();}

Note: Neither clone nor serialization calls the object's construction method;

Serialization does not serialize static and transient-modified variables;

Code reference: Shallow copy and deep copy (talk about clone in Java)

　　　　　　　　Java serialization and Static

Shallow copy and serialization of Java deep copy