log4j.properties中某些代碼是不是被注釋掉了？注釋掉就不顯示了。

###?direct?log?messages?to?stdout?###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE}?%5p?%c{1}:%L?-?%m%n

###?direct?messages?to?file?hibernate.log?###
#log4j.appender.file=org.apache.log4j.FileAppender
#log4j.appender.file.File=hibernate.log
#log4j.appender.file.layout=org.apache.log4j.PatternLayout
#log4j.appender.file.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

已經(jīng)引入log4j的包了。

是否引入了log4j的jar包？