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Creating run time object

angelin precilla
Ranch Hand

Joined: Sep 11, 2007
Posts: 33
Only during runtime , i know the class for which i need to create the object.How to generate objects for that class in java?

I did like
Class CN= Class.forName("nxo.ebs.newproject2.service.DropdownService");
Object o = CN.newInstance(); -----> java.lang.InstantiationException
bart zagers
Ranch Hand

Joined: Feb 05, 2003
Posts: 234
From the Class javadoc:
InstantiationException - if this Class represents an abstract class, an interface, an array class, a primitive type, or void; or if the class has no nullary constructor; or if the instantiation fails for some other reason.

Most probably your class does not have a default (no-arg) constructor.
Rob Spoor
Sheriff

Joined: Oct 27, 2005
Posts: 19557
    
  16

If you don't have a constructor without parameters, you need to retrieve the right constructor using Class' getConstructor() method, passing the right parameters. Then use that Constructor object to create the new instance, again passing the right parameters.


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angelin precilla
Ranch Hand

Joined: Sep 11, 2007
Posts: 33
Thanks for your comments.
angelin precilla
Ranch Hand

Joined: Sep 11, 2007
Posts: 33
Thanks for your comments.
 
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