liblogback-java binary package in Ubuntu Focal amd64

 Logback is a reliable, generic, fast and flexible logging library for Java.
 It's intended as a successor to the popular log4j project.
 .
 The logback-core module lays the groundwork for the other two modules.
 .
 The logback-classic module can be assimilated to a significantly improved
 version of log4j. Moreover, logback-classic natively implements the SLF4J API
 so that you can readily switch back and forth between logback and other
 logging systems such as log4j or java.util.logging (JUL).
 .
 The logback-access module integrates with Servlet containers, such as Tomcat
 and Jetty, to provide HTTP-access log functionality.

Source package