How do you create a deep copy?
If you want to deep copy an object you will have to traverse the object graph and copy each child object explicitly via the object’s copy constructor or a static factory method that in turn deep copies the child object. Immutables (e.g. String s) do not need to be copied.
Does Java do deep copy?
The deep copy approach in Java will copy the entire object tree and thus make this copy independent from the original object.In this article, we will focus on a deep copy of an object in Java. Deep cloning is closely related to Java serialization.
What is deep copy in Java with example?
Whenever you try to create a copy of an object, in the deep copy all fields of the original objects are copied exactly, in addition to this, if it contains any objects as fields then copy of those is also created (using the clone() method).
What is shallow and deep copy?
A shallow copy constructs a new compound object and then (to the extent possible) inserts references into it to the objects found in the original. A deep copy constructs a new compound object and then, recursively, inserts copies into it of the objects found in the original.
How do you deep copy an ArrayList?
In Java, to support deep copy, we must override the clone() of model classes. In clone() method, we must ensure that when somebody invokes object. clone() method then it must return a deep copy of that model class (e.g. Employee class).
Is equal method in java?
Java String equals() Method
The equals() method compares two strings, and returns true if the strings are equal, and false if not. Tip: Use the compareTo() method to compare two strings lexicographically.
Can we override clone method in java?
Every language which supports cloning of objects has its own rules and so does java. In java, if a class needs to support cloning it has to do following things: You must implement Cloneable interface. You must override clone() method from Object class.
Why do we need deep copy?
Depending upon the resources like dynamic memory held by the object, either we need to perform Shallow Copy or Deep Copy in order to create a replica of the object. In general, if the variables of an object have been dynamically allocated then it is required to do a Deep Copy in order to create a copy of the object.
What is a shallow copy Java?
A shallow copy is a copy of the reference pointer to the object, whereas a deep copy is a copy of the object itself. In Java, objects are kept in the background, what you normally interact with when dealing with the objects is the pointers. The variable names point to the memory space of the object.
What is Externalizable interface in java?
Externalization serves the purpose of custom Serialization, where we can decide what to store in stream. Externalizable interface present in java.io, is used for Externalization which extends Serializable interface. It consist of two methods which we have to override to write/read object into/from stream which are-