How to access the method using the object

[Manoj Paul]

Dear friends...
Can any one tell me what should I do to access the watch() method using the object obj in the following program.

Your suggestion are highly welcomed.

***********************************************************************
public class Manoj
{
String you="YOU";


Manoj()
{
System.out.println("In const");
}
public void watch()
{
System.out.println("In Watch");
}

public static void main(String a[]) throws
InstantiationException,IllegalAccessException
{
try
{
Object obj = Class.forName("Manoj").newInstance();
//obj.watch();
//System.out.println("Your Entered String: "+obj.you );

}
catch(Exception e)
{
System.out.println("Ex: "+e);
}

}
}
*********************************************************************

[Ganesh Kumar]

Hi manoj,

" Object obj = Class.forName("Manoj").newInstance();" Their is a problem with this line i suppose.If we create a instance by new its working instead of the above.

Ganesh Kumar

[Manoj Paul]

But Ganesh,
I don't want to use the new operator here, because we can create an object without using new operator too. Run the program, you can see that an object is already created, because the constructor is called in the process. But when i tried to access the method watch() with the help of the object obj, its not working, thats what i want to know and what should i do to access the method.

But I am yet to get any help.
Thank you

[Ganesh Kumar]

Ya manoj what you said is right.Lets wait anyone will help us

[Ulf Dittmer]

Since you know what kind of object "obj" is, you can cast it:

Manoj obj = (Manoj) Class.forName("Manoj").newInstance();
obj.watch();

You'll need to catch ClassCastException as well.


An interesting twist would be to use an interface here:

public interface Watch {   
    public void watch();
}
 
public class Manoj implements Watch {
...
}
 
public class Ganesh implements Watch {
...
}

The you can instantiate all kinds of classes, and don't have to know which one it is in particular:

Watch obj = (Watch) Class.forName("Manoj").newInstance();
obj.watch();
 
obj = (Watch) Class.forName("Ganesh").newInstance();
obj.watch();

[Ganesh Kumar]

Thanks Ditmer

[Manoj Paul]

Thank you Ulf, your suggestion was very helpful. Now I am able to compile and run the program efficiently. Thanks once again.