Migrating from log4j 1.2 to log4j 2: LevelRangeFilter

Question

What is the log4j 2 equivalent of the following log4j 1.2 configuration?

<filter class="org.apache.log4j.varia.LevelRangeFilter">
    <param name="LevelMin" value="DEBUG" />
    <param name="LevelMax" value="INFO" />
</filter>

Lugansk

Answer 1

Instead of having to create your own filter (http://bitfish.eu/java/log4j-2-multiple-appenders-with-different-log-levels/) you can simply use a composite filter with two ThresholdFilters:

<Filters>
    <ThresholdFilter level="DEBUG"/>
    <ThresholdFilter level="WARN" onMatch="DENY" onMismatch="NEUTRAL"/>
</Filters>

Lugansk

The bitfish link you mentioned is dead! – Morbidity

what about doing the same in .properties file instead of xml – Melleta

Answer 2

We can use below Filter.

<LevelRangeFilter minLevel="DEBUG" maxLevel="DEBUG" onMatch="ACCEPT" onMismatch="DENY"/>

Howlend

Answer 3

Following appender configurations help to separate writing to stdout and stderr (useful e.g. within eclipse whose console displays the stderr in red).

log4j2 V2.19

<Console name="stdout" target="SYSTEM_OUT">
   <PatternLayout ...
   <LevelRangeFilter minLevel="INFO" maxLevel="ALL" onMatch="ACCEPT" onMismatch="DENY"/>
</Console>
<Console name="stderr" target="SYSTEM_ERR">
   <PatternLayout ...
   <LevelRangeFilter minLevel="FATAL" maxLevel="WARN" onMatch="ACCEPT" onMismatch="DENY"/>
</Console>

One remark on the min/max-Level property: it's somehow contra-intuitive, since FATAL is the smallest, ALL is the highest level.

Rovelli