Reflection in Java - ClassCastException

import java.lang.reflect.*;


class Start
{
  public static void main( String[] argv ) 
  {
      String me, klasa;
      Object arg;
      Method met;

      int v=argv.length-1;
      int argc =argv.length;

      if ( argc == 0 ) {
          System.err.println( "err!!!");
          return;
      }

      try 
      {   while (argc!=0)
      {
          Class<?> c = Class.forName(argv[v]);
          klasa = (String) c.newInstance();

          Method[] m = InfoInterface.class.getMethods();

          arg =  m[2].invoke(c.newInstance());
          me = (String) m[1].invoke(c.newInstance());
          klasa = (String) m[0].invoke(c.newInstance());                  

          met = klasa.getClass().getMethod(me, String.class);
          met.invoke(klasa, arg);
          --argc;
      }    

      }
      catch ( Exception e ) { System.out.println(e) ; return; }
    }
}

I dont know why in this code shows me ClassCastException. I have searched the error since hour and i have no idea what's wrong with it. Help me please!

The classes to program are add via commend line.