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From Daniel Kehoe <ke...@fortuity.com>
Subject Re: can't dynamically load a class?
Date Wed, 16 Feb 2000 21:30:20 GMT
At 12:35 PM -0700 2/16/00, Danno Ferrin wrote:
>With the new context specs in Servlet 2.2 some different things are
>required to happen with classloader, such as each context has a separate
>classloader instance.
>
>try Class.forName("foo", this.getClass().getClassLoader())

The syntax is
Class.forName(String name, boolean initialize, ClassLoader loader)
so I tried
myReport = (myReportInterface)Class.forName(dynamicReportName, true, 
this.getClass().getClassLoader()).newInstance();
but I still get ClassNotFoundException.

Is it known to work?

Daniel
>kehoe@fortuity.com



>Daniel Kehoe wrote:
> >
> > I'm trying to use the method Class.forName in a servlet and it
> > doesn't work with Tomcat (worked fine with JServ and Jrun). I get a
> > ClassNotFoundException. It should work, right?
> >
> > Daniel
> > kehoe@fortuity.com
> >
> > >Date: Mon, 14 Feb 2000 16:47:17 -0800
> > >To: tomcat-dev@jakarta.apache.org
> > >From: Daniel Kehoe <kehoe@fortuity.com>
> > >Subject: why ClassNotFoundException on attempt to dynamically 
>load a class?
> > >
> > >Why does this code throw an exception
> > >"java.lang.ClassNotFoundException: SpecificReport"?
> > >
> > >String dynamicReportName = "SpecificReport";
> > >myReport = 
>(myReportInterface)Class.forName(dynamicReportName).newInstance();
> > >
> > >It works fine if I just instantiate the object:
> > >SpecificReport aSpecificReport = new SpecificReport();
> > >
> > >And it works fine under Jserv or Jrun.
> > >
> > >I hear someone asking, why does he want to do this? Answer: I want
> > >to load a class dynamically based on a parameter passed from the
> > >browser, like:
> > >String dynamicReportName = request.getParameterValues("report")[0];
> > >
> > >I'm using Tomcat 3.1M1 with java 1.2.2 Classic VM (build
> > >Linux_JDK_RC3, native threads, sunwjit). What's going on that's
> > >different?
> > >
> > >Thanks!
> > >
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> >
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