Archetype generatedArchetype = new Archetype();
generatedArchetype.setGroupId( "groupId" );
generatedArchetype.setArtifactId( "artifactId" );
generatedArchetype.setVersion( "1" );
generatedArchetype.setRepository( "http://localhost:" + port + "/repo/" );
catalog.addArchetype( generatedArchetype );
File catalogFile = new File( catalogDirectory, "archetype-catalog.xml" );
ArchetypeCatalogXpp3Writer catalogWriter = new ArchetypeCatalogXpp3Writer();
Writer writer = new FileWriter( catalogFile );
catalogWriter.write( writer, catalog );