Nasıl Logback farklı yerler için bir logger için farklı düzeylerde oturum açmak için yapılandırabilirsiniz?

Aşağıdaki model alınarak yapılandırmayı ele alalım, örneğin, model alınarak STDOUT INFO mesaj kaydı STDERR ERROR mesajlar?

(Bu örnek örnek logback-examples/src/main/java/chapters/configuration/sample4.xml Chapter 3: Logback Configuration gösterilen) bir türevi olduğunu unutmayın.

<configuration>
  <appender name="STDOUT"
   class="ch.qos.logback.core.ConsoleAppender">
   <encoder>
     <pattern>
        %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
      </pattern>
    </encoder>
  </appender>
  <appender name="STDERR"
   class="ch.qos.logback.core.ConsoleAppender">
   <encoder>
     <pattern>
        %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
      </pattern>
    </encoder>
    <target>System.err</target>
  </appender>
  <!-- What is the effective level of "chapters.configuration"? -->
  <logger name="chapters.configuration" level="INFO" additivity="false">
    <appender-ref ref="STDOUT" />
  </logger>
  <logger name="chapters.configuration" level="ERROR" additivity="false">
    <appender-ref ref="STDERR" />
  </logger>

  <!-- turn OFF all logging (children can override) -->
  <root level="OFF">
    <appender-ref ref="STDOUT" />
  </root>
</configuration>

Logback filters ile bazı ilginç şeyler yapabilirsiniz. Yapılandırma altında tek stderr ve stdout her şey için uyarmak ve hata iletileri yazdırılır.

logback.xml

<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
  <target>System.out</target>
  <filter class="com.foo.StdOutFilter" />
   ...
</appender>

<appender name="stderr" class="ch.qos.logback.core.ConsoleAppender">
  <target>System.err</target>
  <filter class="com.foo.ErrOutFilter" />
   ...
</appender>

<logger name="mylogger" level="debug">
    <appender-ref ref="stdout" />
    <appender-ref ref="stderr" />
</logger>

com.foo.StdOutFilter

public class StdOutFilter extends ch.qos.logback.core.filter.AbstractMatcherFilter
{

    @Override
    public FilterReply decide(Object event)
    {
        if (!isStarted())
        {
            return FilterReply.NEUTRAL;
        }

        LoggingEvent loggingEvent = (LoggingEvent) event;

        List<Level> eventsToKeep = Arrays.asList(Level.TRACE, Level.DEBUG, Level.INFO);
        if (eventsToKeep.contains(loggingEvent.getLevel()))
        {
            return FilterReply.NEUTRAL;
        }
        else
        {
            return FilterReply.DENY;
        }
    }

}

com.foo.ErrOutFilter

public class ErrOutFilter extends ch.qos.logback.core.filter.AbstractMatcherFilter
{

    @Override
    public FilterReply decide(Object event)
    {
        if (!isStarted())
        {
            return FilterReply.NEUTRAL;
        }

        LoggingEvent loggingEvent = (LoggingEvent) event;

        List<Level> eventsToKeep = Arrays.asList(Level.WARN, Level.ERROR);
        if (eventsToKeep.contains(loggingEvent.getLevel()))
        {
            return FilterReply.NEUTRAL;
        }
        else
        {
            return FilterReply.DENY;
        }
    }

}