I would like to change the Logger outpout

General Discussion
1

Hi,

I’m using Liquibase API with a Java application and for methods like “update”, “rollback”, etc. I would like to get the entire log data (every Info, Debug, Warning and Severe data) into a file.

Currently, by default, Logger’s output is the standard one (I guess) but how can I change it, if it’s possible.

Thanks for your time.

2

Hi! May I ask which version of Liquibase you are using? Also, are you embedding Liquibase into an existing application or are you running it by other means (command line, Maven, Ant, etc)?

3

Hi,
I’m using 3.8.9 version.
Actually, I made a java server which allows me to run liquibase commands (as “update”, “updateSQL”, etc…). Those commands are ran by the java class “Liquibase” (https://www.liquibase.org/javadoc/liquibase/Liquibase.html) ; so I run Liquibase commands by the object methods into my own application.
And this object is ‘associated’ to an other one, “Logger” (https://www.liquibase.org/javadoc/liquibase/logging/Logger.html), which prints all logging informations on the standard output (I suppose).
I hope I was clearer, tell me if not.

4

Based on my research, version 3.8.9 uses SLF4J as its default logging framework. It also seems to pull in logback-classic as the SLF4J implementation. By default, SLF4J and logback-classic log to standard out. If you want to change how the logging works you have a few options:

  1. Create a logback.xml file in your classpath and change the appenders for the logback loggers to go to a file. You can get more information on Logback at their web site. http://logback.qos.ch/
  2. Stop using Logback and add one of SLF4J’s bridge jars to route the SLF4J’s log output to the logging framework of your choice. http://www.slf4j.org/legacy.html
  3. Create your own logger by implementing the Logger and LoggerFactory interfaces.

There may be other options but that’s what I was able to gather reading the 3.8.x code. I think I would go with option 1 but I generally choose SLF4J and Logback myself when I write programs.

Hope this helps. Let me know if you have additional questions.