public void accept() throws Exception {
// set up appender
Layout layout = new SimpleLayout();
Appender appender = new FileAppender(layout, ACCEPT_FILE, false);
// create LevelMatchFilter
LevelMatchFilter matchFilter = new LevelMatchFilter();
// attach match filter to appender
appender.addFilter(matchFilter);
// attach DenyAllFilter to end of filter chain to deny neutral
// (non matching) messages
appender.addFilter(new DenyAllFilter());
// set appender on root and set level to debug
root.addAppender(appender);
root.setLevel(Level.TRACE);