Replace commons logging: Another Java log package: slf4j

Yes ~! Yet another Java logging API

Java currently has a total of four log packages: log4j, JDK logging, commons logging, and slf4j. log4j and JDK logging are encapsulation of logs, commons logging and slf4j encapsulate log APIs. if you go through the document, you will find that every logapi tells you "we provide a standard way to use logs", but there are several standards available, instead, people cannot know what is the real "standard"

It is said that slf4j is an improvement to commons logging and there will no longer be a disgusting classloader problem. slf4j uses the compiler to bind the underlying implementation to avoid classloader problems, A small defect in doing so is that it is impossible to bind the underlying implementation (or even not)

Slf4j provides support for commons logging, so commons logging can be seamlessly migrated. Hopefully this is good news.