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.

Comments

Getting key/value pair from JSON object and getting variable name and value from JavaScript object.

Hi, I had faced one issue like this. I have an JSON object but I don't know any key name but I need to get the all the key and corresponding value from JSON object using client side JavaScript. Suddenly I wondered whether it's possible or not, after that I had done lot of workaround and finally got this solution. See the below example. function getKeyValueFromJSON() { var jsonObj = {a:10,b:20,c:30,d:50} ; for ( var key in jsonObj) { alert( "Key: " + key + " value: " + jsonObj[key]); } } In this example I have created the one json array as string, and converted this string into JSON object using eval() function. Using for-each loop I got all the key value from jsonObj, and finally using that key I got the corresponding value. Finally I got the alert like this, Key: a value:10 Key: b value:20 Key: c value:30 Key: d value:50 During this workaround I got one more idea, using this same way I got

Simple Login Application Using Spring MVC and Hibernate – Part 1

I hope developers working in web application development might hear about MVC architecture. Almost all technologies provide support for MVC based web application development, but the success is based on many factors like reusable of the code, maintenance of the code, future adaption of the code, etc.., The success of the Spring MVC is “ Open for extension and closed for modification ” principle. Using Spring MVC the developers can easily develop MVC based web application. We don’t need any steep learning curve at the same time we need to know the basics of spring framework and MVC architecture. The Spring MVC consists of following important components. 1. Dispatcher servlet 2. Controller 3. View Resolver 4. Model Spring MVC - Overview The overall architecture of Spring MVC is shown here. 1. When “Dispatcher Servlet” gets any request from client, it finds the corresponding mapped controller for the request and just dispatches the request to the corresponding contro

Simple Login Application Using Spring MVC and Hibernate – Part 2

I hope you have visited my part1 of my tutorial . Let’s see the steps for integrating hibernate framework into Spring MVC. Here I have used MySQL database. I have created one database called “ springmvc ” and created one table called “ user ” with userid, username, password fields. I have inserted some records into table like this. Step 1: Creating User POJO class. We need to create a User POJO class for mapping user table. Ok let’s create it. Step 2: Creating hibernate mapping xml file for user class. In hibernate we need to create hibernate mapping xml file for all domain class for mapping into corresponding database table. Instead of creating xml file you can use annotation for mapping domain class into database table. This is my mapping xml document created for mapping our user domain class into user database table. Step 3: Creating authenticate service class. The method “verifyUserNameAndPassword” present in “AuthenticateService”

Gnanasuriyan

Search This Blog