Creating Copy of the Existing Object in Java Using Clone Method

  In Java, The "Object" class is the root class for all java classes, It means by default all the java classes inherit the Object class. The Object class have some useful methods for performing operation on the class object like clone(), getClass(), equals(), toString(), wait(), etc..,

  The clone() methods is used for creating copy of the existing object. It's means it allocated the new memory for object with values and methods present in which object you are going to copy. For performing this clone() operation you have to implement the Cloneable interface and you have to override the clone() method. See the below example.

public class CloneDemo implements Cloneable {

public int testValue;

public CloneDemo(int value) {

this.testValue = value;

}

//Override the clone() method 

protected Object clone() {

Object newObject = null;

try{

newObject = super.clone();

}

catch(CloneNotSupportedException e){

e.printStackTrace();

}

return newObject;

}

//Main mthod

public static void main(String[] args) {

CloneDemo obj1 = new CloneDemo(10);

CloneDemo obj2 = (CloneDemo) obj1.clone();

System.out.println("The integer value present in object1 : " + obj1.testValue);

System.out.println("The integer value present in object2 : " + obj2.testValue);

}

}

  Here I have create the CloneDemo class and implemented Cloneable interface and override the clone() method for getting copy of the class. In my main method I have created the new object for my class "CloneDemo" and I created the copy of the object1 by calling obj1.clone() method. Finally I printed the value of integer "testValue" present in both objects. The final result should be like this only.

The integer value present in object1 : 10

The integer value present in object2 : 10


Note:
  Hey don't assume the obj1 and obj2 are equals because the obj2 is the copy the obj1, so both objects are not equals. If you compare these two object using equals() method that will returns false.