How many ways can we create an object

[Pandu Rangam]

Hi all,
How many ways can we create an object. To my knowledge
1) using new operator
2) using Class.forName(ClassName);
3) using clone method
are these correct, any one I missedout ?

[Deepak Bala]

Class.forName(ClassName)

That just loads the class dont it ? You never get a reference to a usable object in the heap. That is... you get a class descriptor that just gives you info about this class.

How about String x = "hello"; ? Objects are created in the pool.

[Cameron Wallace McKenzie]

Could you say, let the JVM create one for you? Isn't that what happens with Java 1.5 autoboxing?

   
 
Vector v = new Vector();
int i =10;  /*primitive type*/
v.add(i); /*autoboxing creates a new, big I, Integer*/
 

Similary, the new keyword doesn't need to be used with String objects, or when creating arrays. Does that count?

Isn't 'using a clone method' the same as say, using a 'factory' method? After all, isn't the JVM just using the new keyword behind the scenes? Philisophical argument I guess.

This is stated purely out of ignorance of the API, but can you do something funky with reflection as well? Just a thought.

-Cameron McKenzie

[Stan James]

Reading from an object stream might count as another way.

Yes, reflection is another option. class.forName().newInstance() only invokes no-args constructors. For other constructors you have to dig deeper into reflection.

Did we just do some homework?