一：首先来看一个图
commons-logging和slf4j都是日志的接口，供用户使用，而没有提供实现！后面的log4j，slf4j-nop等才是他们的实现。
二：Hibernate框架的slf4j-api-1.5.8.jar
Hibernate默认用的是slf4j-nop.jar日志实现方式。
但是我们可以替换成log4j的实现。但不是简单的加上log4j-1.2.17.jar就行了。中间还需要一个转换器slf4j-log4j12-1.5.8.jar
然后在src目录下加上log4j.properties
### direct log messages to stdout ###log4j.appender.stdout=org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.Target=System.outlog4j.appender.stdout.layout=org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L – %m%n### set log levels – for more verbose logging change 'info' to 'debug' ###log4j.rootLogger=warn, stdout#log4j.logger.org.hibernate=info#log4j.logger.org.hibernate=debug### log HQL query parser activity#log4j.logger.org.hibernate.hql.ast.AST=debug### log just the SQL#log4j.logger.org.hibernate.SQL=debug### log JDBC bind parameters ####log4j.logger.org.hibernate.type=info#log4j.logger.org.hibernate.type=debug### log schema export/update ###log4j.logger.org.hibernate.tool.hbm2ddl=debug### log HQL parse trees#log4j.logger.org.hibernate.hql=debug### log cache activity ####log4j.logger.org.hibernate.cache=debug### log transaction activity#log4j.logger.org.hibernate.transaction=debug### log JDBC resource acquisition#log4j.logger.org.hibernate.jdbc=debug### enable the following line if you want to track down connection ###### leakages when using DriverManagerConnectionProvider ####log4j.logger.org.hibernate.connection.DriverManagerConnectionProvider=trace
日志输出：
22:12:18,627 INFO SchemaUpdate:155 – Running hbm2ddl schema update22:12:18,629 INFO SchemaUpdate:167 – fetching database metadata22:12:18,630 INFO SchemaUpdate:179 – updating schema22:12:18,647 INFO TableMetadata:65 – table found: hibernate.teacher22:12:18,647 INFO TableMetadata:66 – columns: [id, title, name]22:12:18,647 INFO TableMetadata:68 – foreign keys: []22:12:18,647 INFO TableMetadata:69 – indexes: [primary]22:12:18,648 INFO SchemaUpdate:217 – schema update completeHibernate: insert into Teacher (name, title, id) values (?, ?, ?)
，勤勉是通往胜利的必经之路。要是由于胆怯艰难而去另觅佳径，
