Enable simple class name in logger name customization

[twessendorf]

Is your feature request related to a problem? Please describe.
I didn't succeed in shortening the logger name to simple class name. Although it is stated that shortenedLoggerNameLength behaves similar to normal pattern style, <shortenedLoggerNameLength>0</shortenedLoggerNameLength> doesn't result in simple class name as %logger{0} does. In fact, foo.bar.baz.MyClass is shortened to f.b.b.MyClass instead of MyClass.

Describe the solution you'd like
I'd like shortenedLoggerNameLength to behave the same way as normal pattern style for 0 parameter to enable simple class name logger customization.

[brenuart]

Hi @twessendorf ,

First of all, sorry for the late answer :-(
Secondly, there is indeed a problem with how the logger name is shortened when the length is set to 0 (as you noticed). It works however as expected when the length is greater than zero.

As a workaround you can make use of the PatternJsonProvider as shown below:

<encoder class="net.logstash.logback.encoder.LoggingEventCompositeJsonEncoder">
    <providers>
        <pattern>
            <pattern>
                { "logger": "%logger{0}" }
            </pattern>
        </pattern>
    </providers>
</encoder>

Note that you cannot rely on the LogstashEncoder and you will have to redefine all the required JsonProviders manually...