public static int main(String[] args,
    ClassWorld classWorld) 
{
           
        // ----------------------------------------------------------------------
        // Setup the command line parser
        // ----------------------------------------------------------------------
        CLIManager cliManager = new CLIManager();
        CommandLine commandLine;
        try
        {
            commandLine = cliManager.parse( args );
        }
        catch ( ParseException e )
        {
            System.err.println( "Unable to parse command line options: " + e.getMessage() );
            cliManager.displayHelp();
            return 1;
        }
        // TODO: maybe classworlds could handle this requirement...
        if ( "1.4".compareTo( System.getProperty( "java.specification.version" ) )  > 0 )
        {
            System.err.println( "Sorry, but JDK 1.4 or above is required to execute Maven. You appear to be using "
                + "Java:" );
            System.err.println( "java version \"" + System.getProperty( "java.version", "< unknown java version >" )
                + "\"" );
            System.err.println( System.getProperty( "java.runtime.name", "< unknown runtime name >" ) + " (build "
                + System.getProperty( "java.runtime.version", "< unknown runtime version >" ) + ")" );
            System.err.println( System.getProperty( "java.vm.name", "< unknown vm name >" ) + " (build "
                + System.getProperty( "java.vm.version", "< unknown vm version >" ) + ", "
                + System.getProperty( "java.vm.info", "< unknown vm info >" ) + ")" );
            return 1;
        }
        boolean debug = commandLine.hasOption( CLIManager.DEBUG );
        boolean showErrors = debug || commandLine.hasOption( CLIManager.ERRORS );
        if ( showErrors )
        {
            System.out.println( "+ Error stacktraces are turned on." );
        }
        // ----------------------------------------------------------------------
        // Process particular command line options
        // ----------------------------------------------------------------------
        if ( commandLine.hasOption( CLIManager.HELP ) )
        {
            cliManager.displayHelp();
            return 0;
        }
        if ( commandLine.hasOption( CLIManager.VERSION ) )
        {
            showVersion();
            return 0;
        }
        else if ( debug )
        {
            showVersion();
        }
        EventDispatcher eventDispatcher = new DefaultEventDispatcher();
        // ----------------------------------------------------------------------
        // Now that we have everything that we need we will fire up plexus and
        // bring the maven component to life for use.
        // ----------------------------------------------------------------------
        embedder = new Embedder();
        try
        {
            embedder.start( classWorld );
        }
        catch ( PlexusContainerException e )
        {
            showFatalError( "Unable to start the embedded plexus container", e, showErrors );
            return 1;
        }
        // ----------------------------------------------------------------------
        // The execution properties need to be created before the settings
        // are constructed.
        // ----------------------------------------------------------------------
        Properties executionProperties = new Properties();
        Properties userProperties = new Properties();
        populateProperties( commandLine, executionProperties, userProperties );
        Settings settings;
        try
        {
            settings = buildSettings( commandLine );
        }
        catch ( SettingsConfigurationException e )
        {
            showError( "Error reading settings.xml: " + e.getMessage(), e, showErrors );
            return 1;
        }
        catch ( ComponentLookupException e )
        {
            showFatalError( "Unable to read settings.xml", e, showErrors );
            return 1;
        }
        Maven maven = null;
        MavenExecutionRequest request = null;
        LoggerManager loggerManager = null;
        try
        {
            // logger must be created first
            loggerManager = (LoggerManager) embedder.lookup( LoggerManager.ROLE );
            if ( debug )
            {
                loggerManager.setThreshold( Logger.LEVEL_DEBUG );
            }
            else if ( commandLine.hasOption( CLIManager.QUIET ) )
            {
                // TODO: we need to do some more work here. Some plugins use sys out or log errors at info level.
                // Ideally, we could use Warn across the board
                loggerManager.setThreshold( Logger.LEVEL_ERROR );
                // TODO:Additionally, we can't change the mojo level because the component key includes the version and it isn't known ahead of time. This seems worth changing.
            }
            ProfileManager profileManager = new DefaultProfileManager( embedder.getContainer(), executionProperties );
            if ( commandLine.hasOption( CLIManager.ACTIVATE_PROFILES ) )
            {
                String profilesLine = commandLine.getOptionValue( CLIManager.ACTIVATE_PROFILES );
                StringTokenizer profileTokens = new StringTokenizer( profilesLine, "," );
                while ( profileTokens.hasMoreTokens() )
                {
                    String profileAction = profileTokens.nextToken().trim();
                    if ( profileAction.startsWith( "-" ) )
                    {
                        profileManager.explicitlyDeactivate( profileAction.substring( 1 ) );
                    }
                    else if ( profileAction.startsWith( "+" ) )
                    {
                        profileManager.explicitlyActivate( profileAction.substring( 1 ) );
                    }
                    else
                    {
                        // TODO: deprecate this eventually!
                        profileManager.explicitlyActivate( profileAction );
                    }
                }
            }
            request = createRequest( commandLine, settings, eventDispatcher, loggerManager, profileManager,
                                     executionProperties, userProperties, showErrors );
            setProjectFileOptions( commandLine, request );
            maven = createMavenInstance( settings.isInteractiveMode() );
        }
        catch ( ComponentLookupException e )
        {
            showFatalError( "Unable to configure the Maven application", e, showErrors );
            return 1;
        }
        finally
        {
            if ( loggerManager != null )
            {
                try
                {
                    embedder.release( loggerManager );
                }
                catch ( ComponentLifecycleException e )
                {
                    showFatalError( "Error releasing logging manager", e, showErrors );
                }
            }
        }
        try
        {
            maven.execute( request );
        }
        catch ( MavenExecutionException e )
        {
            return 1;
        }
        return 0;
}

 static  void populateProperties(CommandLine commandLine,
    Properties executionProperties,
    Properties userProperties) 
{
        // add the env vars to the property set, with the "env." prefix
        // XXX support for env vars should probably be removed from the ModelInterpolator
        try
        {
            Properties envVars = CommandLineUtils.getSystemEnvVars();
            Iterator i = envVars.entrySet().iterator();
            while ( i.hasNext() )
            {
                Entry e = (Entry) i.next();
                executionProperties.setProperty( "env." + e.getKey().toString(), e.getValue().toString() );
            }
        }
        catch ( IOException e )
        {
            System.err.println( "Error getting environment vars for profile activation: " + e );
        }
        // ----------------------------------------------------------------------
        // Options that are set on the command line become system properties
        // and therefore are set in the session properties. System properties
        // are most dominant.
        // ----------------------------------------------------------------------
        if ( commandLine.hasOption( CLIManager.SET_SYSTEM_PROPERTY ) )
        {
            String[] defStrs = commandLine.getOptionValues( CLIManager.SET_SYSTEM_PROPERTY );
            if ( defStrs != null )
            {
                for ( int i = 0; i <  defStrs.length; ++i )
                {
                    setCliProperty( defStrs[i], userProperties );
                }
            }
            executionProperties.putAll( userProperties );
        }
        executionProperties.putAll( System.getProperties() );
}