protectedvoid subAppend(LoggingEvent event) { this.qw.write(this.layout.format(event)); if (layout.ignoresThrowable()) { String[] s =event.getThrowableStrRep(); if (s !=null) { int len = s.length; for (int i =0; i < len; i++) { this.qw.write(s[i]); this.qw.write(Layout.LINE_SEP); } } } if (this.immediateFlush) { this.qw.flush(); } }