[java] logging hell

logging-hell.md

Logging Hell

types

• thin wrapper ... apache-commons-logging, slf4j
• implementation ... log4j, logback, jul, ...

🧅 thin wrapper

apache-commons-logging 1.2

• 1st search log4j (w/o configuration - classpath:commons-logging.properties)
• else use jul
• else use simple

slf4j 1.7.36

• slf4j-api (no configuration)
• search backend one of (log4j,jdk14,...,simple)
• else Failed to Load Class org.slf4j.impl.StaticLoggerBinder

System.Logger

• from java9 (wtf i didn't know that until now)

🍐 implementation

apache-commons-logging

• w/o backend -> jul

slf4j

• slf4j-jdk14 -> jul

logback

• concern https://blog.kengo-toda.jp/entry/2021/05/31/200807
• i have never seen this in the library (because this is the backend?), so i don't care about logback

log4j2

• check is slf4j backend, if so use slf4j-jdk14 instead
  • log4j-over-slf4j is only for log4j 1.x
• else https://logging.apache.org/log4j/2.x/log4j-jul/index.html, but i've never been succeed this
  • this is jul -> log4j2 🥺
  • log4j-slf4j-impl is also slf4j -> log4j 🥺

java.util.logging

• i choose this bacause no concern about product suspension
• don't ask me "why you don't use facade?", logging is not important thing for me