Re: How to determine subclasses of a class

Olli Plough <oliver@plohmann.com> writes:


  A similar operation exists in the library ?ram.jar?.
  This operation is based on Code by Ralf Ullrich.

  One can find all classes of a jar that have any chosen
  property, as long as this property can be obtained from the
  class reference.

  For example, to find all classes implementing ?java.util.Map?,
  one sets a filter accepting only classes which
  ?java.util.Map? is assignable from:

public boolean accepts( final java.lang.Class class_ )
{ return java.util.Map.class.isAssignableFrom( class_ ); }

  One also needs to provide a starting class to find the jar, which
  is done as follows.

public java.lang.String entryPath(){ return "java.lang.Object"; }

  The jar containing this type will be chosen for exploration.

  However, the client does not need to specify this ?entryPath?,
  as "java.lang.Object" is the default obtained by extending
  ?de.dclj.ram.java.lang.reflect.Finder.DefaultSpecification?.

  The example client is:

public class Main
{ /* based on an idea and on code by Ralf Ullrich from 2006 */

  public static void main( final java.lang.String[] args )
  { new de.dclj.ram.java.lang.reflect.Finder
    ( new de.dclj.ram.java.lang.reflect.Finder.DefaultSpecification()
      {
        public boolean isClassFinder(){ return true; }

        public boolean accepts( final java.lang.Class class_ )
        { return java.util.Map.class.isAssignableFrom( class_ ); }

        }).inspectJar(); }}

class java.lang.ProcessEnvironment
class java.rmi.server.RemoteObjectInvocationHandler$MethodToHash_Maps$1
class java.security.AuthProvider
(...)
class java.util.Properties
class java.util.Hashtable
interface java.util.Map

  The library ?ram.jar? is an early publication in alpha state,
  it is experimental, changing, and mostly undocumented. See:

http://www.purl.org/stefan_ram/pub/ram-jar