Logging support

XWork provides its own layer to support logging - it allows to use many different implementations.

Currently XWork provides support for the following libraries (in that order base on classpath discovery):

• Commons Logging
• SLF4J
• Log4j2
• JDK Logger

Usage

To use given type of library add it as a Maven dependency or drop into WEB-INF/lib folder. XWork LoggerFactory class will use given logging provider if available.

To add logging to your application simply declare a Logger as follow:

Implementing my own factory

You plug in your own logging solution, simple extend LoggerFactory class and provide a delegate which implements Logger interface, like below:

Check the source code to see more details.

Defining which factory to use

Now you must tell XWork/Struts2 to use your implementation, just define system property like below:

-Dxwork.loggerFactory=com.demo.MyLoggerFactory

you can use the same to explicit tell the framework which implementation to use and don't depend on class discovery, eg.:

-Dxwork.loggerFactory=com.opensymphony.xwork2.util.logging.slf4j.Slf4jLoggerFactory

or

-Dxwork.loggerFactory=com.opensymphony.xwork2.util.logging.log4j2.Log4j2LoggerFactory


will enable Slf4j or Log4j2 even if there is commons-logging on classpath available (commons-logging is the first LoggerFactory to look for).