question: protected static String addMavenNamespace ( String effectiveXml , boolean isPom ) { SAXBuilder builder = new SAXBuilder ( ) ; try { Document document = builder . build ( new StringReader ( effectiveXml ) ) ; Element rootElement = document . getRootElement ( ) ; Namespace pomNamespace = Namespace . getNamespace ( "" , "http://maven.apache.org/POM/4.0.0" ) ; rootElement . setNamespace ( pomNamespace ) ; Namespace xsiNamespace = Namespace . getNamespace ( "xsi" , "http://www.w3.org/2001/XMLSchema-instance" ) ; rootElement . addNamespaceDeclaration ( xsiNamespace ) ; if ( rootElement . getAttribute ( "schemaLocation" , xsiNamespace ) == null ) { rootElement . setAttribute ( "schemaLocation" , "http://maven.apache.org/POM/4.0.0 " + ( isPom ? POM_XSD_URL : SETTINGS_XSD_URL ) , xsiNamespace ) ; } ElementFilter elementFilter = new ElementFilter ( Namespace . getNamespace ( "" ) ) ; for ( Iterator < ? > i = rootElement . getDescendants ( elementFilter ) ; i . hasNext ( ) ; ) { Element e = ( Element ) i . next ( ) ; e . setNamespace ( pomNamespace ) ; } StringWriter w = new StringWriter ( ) ; Format format = Format . getPrettyFormat ( ) ; XMLOutputter out = new XMLOutputter ( format ) ; out . output ( document . getRootElement ( ) , w ) ; return w . toString ( ) ; } catch ( JDOMException e ) { return effectiveXml ; } catch ( IOException e ) { return effectiveXml ; } }
target:  method from org.apache.maven.plugins.help.AbstractEffectiveMojo Add a Pom/Settings namespaces to the effective XML content.