详细讲解的参考文章:http://www.codeceo.com/article/log4j-usage.html
极客教程地址: http://wiki.jikexueyuan.com/project/log4j/overview.html
打印 数据库日志
#log4j.logger.java.sql.Connection=DEBUG
#log4j.logger.java.sql.Statement=DEBUG
#log4j.logger.java.sql.PreparedStatement=DEBUG
