// InvokeMain.java

// by Mark Allen Weiss, modified by Kip Irvine
// Updated 12/24/2002

// Shows how to call a method and pass a parameter list, using Method.invoke().
// Also shows how to catch an exception thrown by the invoked method.

import java.lang.reflect.*;

class InvokeMain
{
    public static void main( String[] args )
    {
        invokeMain( "Dragon", new Object[] { new String[] { "Breathing", "Fire" } } );
        invokeMain( "Wizard", new Object[] { new String[] { "Casting", "a","Spell" } } );
    }
    
    public static void invokeMain( String className, Object[] params )
    {
        try
        {
			Class cl = Class.forName( className );
			Class[] mainsParamTypes = new Class[] { String[].class };
			
			Method mainMethod = cl.getDeclaredMethod( "main", mainsParamTypes );
			
			if( !Modifier.isStatic( mainMethod.getModifiers( ) ) )
			    System.out.println( "Oops... main is not static!" );
			if( !Modifier.isPublic( mainMethod.getModifiers( ) ) )
			    System.out.println( "Oops... main is not public!" );
			else if( mainMethod.getReturnType( ) != Void.TYPE )
			    System.out.println( "Oops... main doesn't return void!" ); 
			else
			    mainMethod.invoke( null, params );
        }
        catch( ClassNotFoundException e ) 
        {
            System.out.println( "Class not found: " + className );
        }
        catch( NoSuchMethodException e )
        {
            System.out.println( "No method named main() found in " + className );
        }
        catch( IllegalAccessException e )
        {
            System.out.println( "Cannot invoke main() in " + className );
        }
        catch( InvocationTargetException e )
        {
            System.out.println( e );
            e.getTargetException( ).printStackTrace( );
        }
    }
}


class Wizard
{
    public static void main( String[] args )
    {
        System.out.print( "Wizard.main() is running...\nParameters: ");
        for( int i = 0; i < args.length; i++ )
            System.out.print( args[ i ] + "/" );
        System.out.println( "" );
        
        // enable the following line to demonstrate exceptions
        //throw new RuntimeException( "Exception thrown by Wizard.main()" );    
    }
}   

class Dragon
{
    public static void main( String[] args )
    {
        System.out.print( "Dragon.main() is running...\nParameters: " );
        for( int i = 0; i < args.length; i++ )
            System.out.print( args[ i ] + "/" );
        System.out.println( );      
    }
}