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ClassCastException

Srikkanth Mohanasundaram
Ranch Hand

Joined: Feb 07, 2007
Posts: 185
Hi all,
Most of the time my code breaks it is due to some or other ClassCastException,any precautions i should take?
Sidd Kulk
Ranch Hand

Joined: Feb 20, 2007
Posts: 152
ClassCastException generally creeps in when you try to cast an object of one type into another incompatible type. For e.g.

When you say String s = (String)(an object of StringBuffer);

The above will throw a ClassCastException.
But if an object is a type of the casted object, then it doesn't throw this exception.

e.g.
// this will not throw the exception
Object o = (Object)(any kind of object);

To avoid this kind of Exception, you may use the instanceOf operator to check whether your object is castable into a particular type.

Sid
[ May 16, 2007: Message edited by: Sidd Kulk ]
Srikkanth Mohanasundaram
Ranch Hand

Joined: Feb 07, 2007
Posts: 185
Hi,
Thanks for your reply

Regards,
Srikkanth.M
jayalal jayarathna
Greenhorn

Joined: May 17, 2007
Posts: 4
If U want to know what is the exact class of a given objet (ob),
ob.getClass() will tell U the class name
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 37943
    
  22
Class casting is notoriously error-prone. Avoid it like the plague.

In Java 5 and more recent you use generics; you can specify what kind of object is allowed into a collection etc, and there is no need for class casts in the first place.
Ricky Clarkson
Ranch Hand

Joined: Jul 27, 2006
Posts: 131
Casting is for magicians, not programmers. Stop casting, and you'll stop getting exceptions from casts.
 
I agree. Here's the link: http://aspose.com/file-tools
 
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