@Override
public ServletAppender build() {
	final String name = getName();
	if (name == null) {
		LOGGER.error("No name provided for ServletAppender");
	}
	final ServletContext servletContext = WebLoggerContextUtils.getServletContext();
	if (servletContext == null) {
		LOGGER.error("No servlet context is available");
		return null;
	}
	Layout<? extends Serializable> layout = getLayout();
	if (layout == null) {
		layout = PatternLayout.createDefaultLayout();
	} else if (!(layout instanceof AbstractStringLayout)) {
		LOGGER.error("Layout must be a StringLayout to log to ServletContext");
		return null;
	}
          return new ServletAppender(name, layout, getFilter(), servletContext, isIgnoreExceptions(), logThrowables,
                  getPropertyArray());
}
 

@Override
public void append(final LogEvent event) {
    final String serialized = ((AbstractStringLayout) getLayout()).toSerializable(event);
    if (logThrowables) {
        servletContext.log(serialized, event.getThrown());
    } else {
        servletContext.log(serialized);
    }
}