One very common use, probably the most common, of reflection is the
Class#newInstance() method.  It's also the least complicated.  It's useful for
idioms like maintaining a Map of labels to action handlers, for example.

 Map <String, Class<? extends Handler>> handlers
    = new HashMap <String, Class<? extends Handler>> ();

After one fills the Map, later some other logic can produce a String
representing some desired sub-module of logic, then use the Map to get an
instance of the corresponding handler.

 (error-handling omitted, but don't do that in real life)

 public void handle( String thing ) throws Exception
 {
   Class <? extends Handler> clazz = handlers.get( thing );
   Handler handler = clazz.newInstance();
   handler.handle();
 }

One adds error handling, logging and thread synchronization to that as
appropriate.

Joshua Cranmer <Pidgeot18@verizon.invalid> wrote in news:wQybk.260$wa1.103
@trndny07:

The book _Java Reflection in Action_ by Ira R. Forman and Nate Forman is
useful for a deeper understanding of metadata and reflection.

There is even a figure that will help understand how a Class object can
extend from Object and yet describe any Java object (including a Class
object).

Published prior to JDK 1.5, it doesn't have much about Generics.  There is a
little in the back, based on what was known about Generics at the time.