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Article View: borland.public.jbuilder.java.language
Article #7496

Re: ClassCastException

#7496
From: ct
Date: Fri, 15 Jun 2001 16:48
47 lines
2634 bytes
John McGrath  [TeamB] <ng-b@JPMcGrath.net> wrote:
>On 12 Jun 2001 14:15:44 -0700, ct wrote:
>
>> StateHandler handler = null;
>> try {
>>    Class c1 = Class.forName(handlerName);
>>    Object o = c1.newInstance();
>>    System.out.println("StateMachine: o = " + (SigninHandler)o);
>>    handler = (StateHandler)o;  // exception throws
>> } catch(Exception) {}
>
>I am not sure if I missed something here:
>
>First, I cannot see anywhere that you have said or shown what the value 
>of "handlerName" is.  This would seem to be a somewhat critical piece 
>of information.

handleName = "packagename.SigninHandler";

>Second, how can you tell that an exception is being thrown from the 
>line indicated in the code above.  Your catch block for Exception does 
>not do anything, so it would seem to be pretty hard to tell.
>
>I also note that your catch block is not syntactically correct, but I 
>presume that this was just in your message.
>
>Could you change the code to the following and post the output?

I do have printstack in my code.  The exception points
to line indicated in previous email.

I played more with my app.  If I add 
Object o2= new SigninHandler();
statement, no exception is thrown.  
If we can explain this, maybe we are upto something.

    Class c1 = Class.forName(handlerName);
    Object o = c1.newInstance();
    handler = (StateHandler)o;  // exception throws
    Object o2= new SigninHandler();  // add this line, no exception


ct
>---------------------------------------------------
>Before sending me e-mail, please read:
>    http://www.JPMcGrath.net/newsgroups/e-mail.html
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Subject: Re: ClassCastException
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