Maven 管理的项目，在src/main/resources下新建logback.xml文件。

　　日志的简单使用，三种方式。

1. org.apache.commons.logging.Log

   1 2 3 4 5

   //import org.apache.commons.logging.Log; //import org.apache.commons.logging.LogFactory; private static final Log log = LogFactory.getLog(xxxServiceImpl.class); log.info(Object msg);

2. log4j 1.x 版本：org.apache.log4j.Logger

   1 2 3 4

   //org.apache.log4j.Logger; private final Logger logger = Logger.getLogger(this.getClass()); logger.info(Object msg);

3. log4j 2.x 版本：org.apache.logging.log4j.Logger

   1 2 3

   private static final Logger logger = LogManager.getLogger(xxxClass.class); logger.info(String msg);