jetty-logback/src/main/config/etc/logback-access.xml

<configuration>
  <appender name="STDOUT"
    class="ch.qos.logback.core.ConsoleAppender">
    <layout
      class="ch.qos.logback.access.PatternLayout">
      <Pattern>%h %l %u %user %date "%r" %s %b</Pattern>
    </layout>
  </appender>

  <appender-ref ref="STDOUT" />
</configuration>