Dependencies for displaytag library

I am integrating the displaytag library into my web application. I have used the library at my work, but what I am currently building does not have it currently. When I went to review the dependencies 开发者_StackOverflow社区for installation of the library, I noticed that it had the following listed...

commons-logging
commons-lang
commons-collections
commons-beanutils
log4j

I believe that I have provided all of the commons dependencies that it needs, but I noticed that it also has log4j. I am not currently using log4j as my logging, so I am curious if it will in fact not work if I dont have log4j set up, or if it will be fine and just needs it available.

It doesn't really mention in the installation documentation provided at

Display Tag Installation

This link seems to indicate that log4j is Optional (at least for version 1.2).

The same page mentions that slf4j is Not optional, indicating that the library has been coded using slf4j. If so, instead of log4j, any other logging provider can be substituted.

As mentioned by Raghuram, although log4j is optional for displaytag and slf4j is not optional, the slf4j in turn has a dependency on log4j and it is not optional. Link

Basically displaytag needs log4j indirectly as mentioned here.