Core Java - Object Creation

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Object Creation

In how many ways we can create an object? Explain with example.

Total Answers and Comments: 6

Last Update: June 24, 2009 Asked by: justjiten

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Best Rated Answer

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Submitted by: sreedhar dantam

In Java objects can be created in 4 ways.

1. using new operator
2. First get class reference either using Class.forname or class loader. On this class, create object using 'newInstance' method.
3. Clone
4. Deserialization

Above answer was rated as good by the following members:
vasu123, akhilmisra, uday bhasker reddy, justjiten, agarwal_nishtha08, sharathe, Auxilius, ybrw13a, vaseem35, salil_sp, sushilkotnala, ahamza59, shirishparmar, zjlovezj, aishwarya.srivastava, hemant17, sonalgauravmahajan, piyushbeli, sandip.samanta, bino75, evelinp, sandeep549

December 19, 2008 14:33:19

sreedhar dantam

Member Since: December 2008 Contribution: 2

RE: Object Creation

In Java objects can be created in 4 ways.

1. using new operator
2. First get class reference either using Class.forname or class loader. On this class create object using 'newInstance' method.
3. Clone
4. Deserialization

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10 1

Overall Rating: +9

February 12, 2009 00:05:17

trivenireddy

Member Since: February 2009 Contribution: 2

RE: Object Creation

We can create an object in 5 ways
1)new operator
2)clone
3)de-serialization
4)Instance of
5)Class.forName

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2 1

Overall Rating: +1

February 13, 2009 01:34:59

vishrutha

Member Since: February 2009 Contribution: 1

RE: Object Creation

1. Using new keyword
This is the most common way to create an object in java. I read somewhere that almost 99 of objects are created in this way.

MyObject object new MyObject();

2. Using Class.forName()
If we know the name of the class & if it has a public default constructor we can create an object in this way.

MyObject object (MyObject) Class.forName( subin.rnd.MyObject ).newInstance();

3. Using clone()
The clone() can be used to create a copy of an existing object.

MyObject anotherObject new MyObject();
MyObject object anotherObject.clone();

4. Using object deserialization
Object deserialization is nothing but creating an object from its serialized form.

ObjectInputStream inStream new ObjectInputStream(anInputStream );
MyObject object (MyObject) inStream.readObject();

5. Using class loader
one more is through creation of object using classloader
like

this.getClass().getClassLoader().loadClass( com.amar.myobject ).newInstance();

Now you know how to create an object. But its advised to create objects only when it is necessary to do so.

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12 1

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March 22, 2009 15:22:50

Auxilius

Member Since: March 2009 Contribution: 1

RE: Object Creation

I agree with the answer given by vishrutha with few modifications.

Part 2 and the last is very similar to each other.
Deserialization can not be called as way of object creation.
Clone is useful for normal objects but not for composite objects.

From the perspective of design patterns we have six ways of object creation by GoF. But that is all about design patterns. If you ever heard about singleton objects (one of the six) you should read GoF creational patterns.

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4 0

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April 20, 2009 10:16:59

vaseem35

Member Since: April 2009 Contribution: 1

RE: Object Creation

In only one way. That is using 'new' keyword. Without using 'new' we cannot
create object.

Example:

classname cn new classname();

here classname is name of the your class.

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0 3

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June 24, 2009 08:33:17

ashish_dhole30

Member Since: January 2009 Contribution: 1

RE: Object Creation

1.Using New KeyWord
2.Using ClassForName
3.Clone

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0 1

Overall Rating: -1

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