Hi All,
Thanks again, for support. Made many things more clear.
Thanks
Amit Kumar Verma
On Apr 22, 1:35 am, David Pollak <feeder.of.the.be...@gmail.com>
wrote:
> Amit,
> Class.forName(...) is called reflection in Scala/Java land. It allows you
> to get a class based on a String. You can then create a new instance of the
> class with the newInstance() method. However, what you get is an instance
> of Object... and you have to case it into something else before using it.
>
> In Java, there's only one way to cast things:
>
> Object o = someClass.newInstance();
> FooBar fb = (FooBar) o;
>
> In Scala, there are two ways to cast (one is safer and less verbose, the
> other is intentionally more verbose):
>
> val a: AnyRef = someClass.newInstance
> val fb: FooBar = a.asInstanceOf[FooBar]
>
> or (the radically better way)
> a match {
> case fb: FooBar => ...
> case _ => ...
>
> }
>
> Hope this helps.
>
> Thanks,
>
> David
>
> On Mon, Apr 20, 2009 at 4:41 AM, Amit Kumar Verma <cdac.a...@gmail.com>wrote:
>
>
>
>
>
> > Hi All,
>
> > This is a sample function for making an object from string at run
> > time. Here we are not casting the object but creating one. I wanted
> > the same thing for casting the object.
>
> > public static Object bindObject(Class className) {
> > Object objOutput = null;
> > try {
> > String sClassName = className.getPackage().getName().concat
> > (".Wrap".concat(className.getSimpleName()));
> > objOutput = Class.forName(sClassName.replaceFirst
> > ("com.vtech", "com.vtech.appxtension")).newInstance();
> > } catch (Exception e) {
> > try {
> > objOutput = Class.forName(className.getName
> > ()).newInstance();
> > } catch (Exception e1) {
> > e1.printStackTrace();
> > }
> > }
>
> > return objOutput;
> > }
>
> > Thanks to all for kind support..
> > Amit Kumar Verma
>
> > On Apr 18, 8:51 pm, Timothy Perrett <timo...@getintheloop.eu> wrote:
> > > So your talking about reflection right? Take a look at scala Manifests
> > > (which aide getting round type erasure) - other than that scala supports
> > all
> > > the normal reflection tooling that Java does.
>
> > > Tim
>
> > > On 18/04/2009 06:56, "Amit Kumar Verma" <cdac.a...@gmail.com> wrote:
>
> > > > "Scala is a static language, so the class for casting must be known at
> > > > compile time. It's not possible to construct a String at runtime and
> > > > cast
> > > > an object into a class represented by that String. "
>
> > > > But we use this feature in Java for casting the objects.
>
> --
> Lift, the simply functional web frameworkhttp://liftweb.net
> Beginning Scalahttp://www.apress.com/book/view/1430219890
> Follow me:http://twitter.com/dpp
> Git some:http://github.com/dpp
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