protected void initZipOutputStream ( ZipArchiveOutputStream zOut ) throws ArchiverException , IOException { // If no webxml file is specified, it's an error. if ( expectWebXml && deploymentDescriptor == null && ! isInUpdateMode ( ) ) { throw new ArchiverException ( "webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode)" ) ; } super . initZipOutputStream ( zOut ) ; }
override of parent ; validates configuration before initializing the output stream .