Different ways to create an object in java

You must have used the “new” operator to create an Object of a Class. But is it the only way to create an Object?
Simple Answers is NO, then in how many ways we can create Object of a Class. There are several like

• Using New Instance
• Using Clone
• Using Deserilization
• Using ClassLoader
• … don’t know  

Live Exmaple :

 Just Copy Code and run the example

ChildClass.java


/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package objects;

import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * %WY
 * 
 * @version 1.1 
 * @since  practice 8/28/13
 * 
 * @author Srikanth Ganji
 * 
 */

public class ChildClass {
    private ParrentClass dummyObject=null;
    private Class class1=null;
    private ParrentClass firstType()
   {
       System.out.println("\n\n>>>>>>>>>>>>> 1)  Normal Way Creating Object  <<<<<<<<<<<<<<<<< ");
       System.out.println("\n \t using new Operator. \n\t Eg:- new ParrentClass(); ");
       return new ParrentClass();
   }
    private ParrentClass secondType() throws ClassNotFoundException, InstantiationException, IllegalAccessException
    {
        try {
            System.out.println("\n\n>>>>>>>>>> 2) Created Object Using Class.forName(\"\"); <<<<<<<<<<<<<<<<<");
            System.out.println("\n Class.forName(\"objects.ParrentClass\"); ");
            System.out.println("\n \tInner Opperation \n\t We can also use it to"
                    + "\ncreate the object of a class. Class.forName actually loads the"
                    + "\n class in Java but doesn’t create any Object. To Create an Object"
                    + "\n of the Class you have to use newInstance method of Class class. ");
            class1=Class.forName("objects.ParrentClass");
            dummyObject=(ParrentClass)class1.newInstance();
        } catch (ClassNotFoundException ex) {
           throw new ClassNotFoundException("Excepiton on Load Class in Java ");
        } catch (InstantiationException ex) {
           throw new InstantiationException("Exception on Instiallizing Object  Class Object Initialted to Object");
        } catch (IllegalAccessException ex) {
            throw new IllegalAccessException("Excetion on IllegalAccessExcepion On Class Object Initialted to Object");
        }
        
        return dummyObject;
        
    }
    private ParrentClass thiredType() throws CloneNotSupportedException
    {
        
        System.out.println("\n\n>>>>>>>>>>>> 3)  Creating Object Using Clone <<<<<<<<<<<<<<<<<");
        System.out.println("\n\t We can also use Clone() method to create a copy of an existing Object. ");
        try {
            dummyObject=ParrentClass.INSTANCE.clone();
            System.out.println("\n \t Ex:-  dummyObject=ParrentClass.INSTANCE.clone(); ");
            System.out.println("\" Note \" \n \t 1) Here we are creating the clone of an existing Object and not any new Object.   ");
            System.out.println(" \n\t 2) Clone method is declared protected in Object class. So it can be accessed only"
                    + " \n\t in subclass or in same package. That is the reason why it has been overridden here in Class. ");
            System.out.println("\n\t 3)Class need to implement Cloneable Interface otherwise \n\t it will throw CloneNotSupportedException. ");
        } catch (CloneNotSupportedException ex) {
           throw new CloneNotSupportedException("\n Exception Raised when Object Cloning ");
        }
        
        return dummyObject;
    }
    private ParrentClass fourthType()
    {
        System.out.println("\n\n>>>>>>>>>>>>> 4) Creating Object Using Factory Methods ");
        System.out.println("\n\t public static ParrentClass INSTANCE=getInstance();  ");
        System.out.println("\n\t  public static ParrentClass getInstance() \n" 
                +"    { "
                + "\n        return new ParrentClass();"
                + "\n    } ");
        System.out.println("\n\t return ParrentClass.INSTANCE; ");
        
        
        return ParrentClass.INSTANCE;
    }
    private ParrentClass fifthType() throws ClassNotFoundException, InstantiationException, IllegalAccessException
    {
  System.out.println("\n\n 5)>>>>>>>>>>>>>>  Creating Object Like CLass.forName(\"\"); <<<<<<<<<<<<");
        try {
            System.out.println("\n\t Ex:- \n\t"
                    + "   dummyObject=(ParrentClass) this.getClass() \n" +
"                                            .getClassLoader().loadClass(\"objects.ParrentClass\").newInstance(); ");

            dummyObject=(ParrentClass) this.getClass()
                                            .getClassLoader().loadClass("objects.ParrentClass").newInstance();
        } catch (ClassNotFoundException ex) {
           throw new ClassNotFoundException("Excepiton on Load Class in Java ");
        } catch (InstantiationException ex) {
           throw new InstantiationException("Exception on Instiallizing Object  Class Object Initialted to Object");
        } catch (IllegalAccessException ex) {
            throw new IllegalAccessException("Excetion on IllegalAccessExcepion On Class Object Initialted to Object");
        }
        return dummyObject;
    }
    public static void main(String...str)
    {
        ChildClass childClass=new ChildClass();
        ParrentClass obj1,obj2,obj3,obj4,obj5;
        obj1=childClass.firstType();
        try {
            obj2=childClass.secondType();
        } catch (ClassNotFoundException ex) {
            
            System.out.println(" "+ex.getMessage());
            ex.printStackTrace();
        } catch (InstantiationException ex) {
            System.out.println(" "+ex.getMessage());
            ex.printStackTrace();
        } catch (IllegalAccessException ex) {
            System.out.println(" "+ex.getMessage());
            ex.printStackTrace();
        }
        try {
            obj3=childClass.thiredType();
        } catch (CloneNotSupportedException ex) {
            System.out.println(" "+ex.getMessage());
            ex.printStackTrace();
        }
        obj4=childClass.fourthType();
        try {
            obj5=childClass.fifthType();
        } catch (ClassNotFoundException ex) {
            System.out.println(" "+ex.getMessage());
            ex.printStackTrace();
        } catch (InstantiationException ex) {
            System.out.println(" "+ex.getMessage());
            ex.printStackTrace();
        } catch (IllegalAccessException ex) {
            System.out.println(" "+ex.getMessage());
            ex.printStackTrace();
        }
    }
    
}





ParrentClass.java

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package objects;

/**
 *
 * @author Srikanth Ganji
 */
public class ParrentClass implements Cloneable{
    
    int x=100;
    @Override
    protected ParrentClass clone() throws CloneNotSupportedException {
        return (ParrentClass) super.clone();
    }
    public static ParrentClass INSTANCE=getInstance();
    
    public static ParrentClass getInstance()
    {
        return new ParrentClass();
    }
    public ParrentClass getObject()
    {
        return this;
    }
    
}