Can custom appenders created for log4j (extending AppenderSkeleton) be used with new logback framework? I know that logback comes with its own set of appenders similar to log4j, but is this possible to re-use existing ones? How?
The following document describes how to "[migrate] custom log4j components such as appenders or layouts to logback-classic":
It should be easy to port a log4j appender to logback. There is even a document describing the process. However, if you run into problems (which you should not), don't hesitate to ask for help on the logback-dev mailing list.
No, logback appenders need to implement logback's Appender interface. Should be feasible to write a wrapper appender if you wanted to use an existing log4j appender.
来源：https://stackoverflow.com/questions/974817/does-logback-support-log4j-appenders