Hibernate4配置log4j日志环境

        为了便于调试和查看Hibernate自动生成的SQL语句和详细信息，Hibernate4本身自带了slf4j-api-1.6.1日志JAR包，但是使用不太流行，现在是使用log4j来实现Hibernate的日志信息。

1、访问log4j官方网站http://logging.apache.org/log4j/，去下载log4j的JAR包，现在的稳定版本是Apache log4j 1.2.16。下载完成后将log4j-1.2.16.jar包导入到Hibernate项目中。

2、在src目录下设置log4j的配置文件log4j.properties，可以直接复制hibernate-release-4.1.2.Final\project\etc\log4j.properties到src目录中，其默认内容为：

### 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

-------------用户可以根据自己需要选择性的输出想要的信息。此处我们将log4j.logger.org.hibernate=debug和log4j.logger.org.hibernate.type=info都注释掉，仅仅输出log4j.logger.org.hibernate.tool.hbm2ddl=debug的信息，则log4j.properties的内容为：

### 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

3、运行测试类，得到日志信息。

11:33:59,165  WARN DTDEntityResolver:74 - HHH000223: Recognized obsolete hibernate namespace http://hibernate.sourceforge.net/. Use namespace http://www.hibernate.org/dtd/ instead. Refer to Hibernate 3.6 Migration Guide!
11:34:00,659  INFO SchemaExport:343 - HHH000227: Running hbm2ddl schema export
11:34:00,660 DEBUG SchemaExport:353 - Import file not found: /import.sql
Hibernate: drop table if exists User
Hibernate: create table User (id integer not null, name varchar(255), age integer, primary key (id))
11:34:00,679  INFO SchemaExport:405 - HHH000230: Schema export complete
Hibernate: insert into User (name, age, id) values (?, ?, ?)

---------------Hibernate配置文件hibernate.cfg.xml中配置<property name="hbm2ddl.auto">create</property>则会出现以上日志信息。

---------------若在上面的基础上配置<property name="format_sql">true</property>，使得在log中打印出更漂亮的SQL，则得出日志信息：

12:41:46,280  WARN DTDEntityResolver:74 - HHH000223: Recognized obsolete hibernate namespace http://hibernate.sourceforge.net/. Use namespace http://www.hibernate.org/dtd/ instead. Refer to Hibernate 3.6 Migration Guide!
12:41:47,014  INFO SchemaExport:343 - HHH000227: Running hbm2ddl schema export
12:41:47,014 DEBUG SchemaExport:353 - Import file not found: /import.sql
Hibernate:
drop table if exists User
Hibernate:
create table User (
id integer not null,
name varchar(255),
age integer,
primary key (id)
)
12:41:47,056  INFO SchemaExport:405 - HHH000230: Schema export complete
Hibernate:
insert
into
User
(name, age, id)
values
(?, ?, ?)

 -----------若设置为<property name="hbm2ddl.auto">update</property>则会出现以下日志信息：

12:47:48,840  WARN DTDEntityResolver:74 - HHH000223: Recognized obsolete hibernate namespace http://hibernate.sourceforge.net/. Use namespace http://www.hibernate.org/dtd/ instead. Refer to Hibernate 3.6 Migration Guide!
12:47:49,546  INFO SchemaUpdate:182 - HHH000228: Running hbm2ddl schema update
12:47:49,546  INFO SchemaUpdate:193 - HHH000102: Fetching database metadata
12:47:49,548  INFO SchemaUpdate:205 - HHH000396: Updating schema
12:47:49,573  INFO TableMetadata:65 - HHH000261: Table found: hibernate.user
12:47:49,573  INFO TableMetadata:66 - HHH000037: Columns: [id, age, name]
12:47:49,574  INFO TableMetadata:68 - HHH000108: Foreign keys: []
12:47:49,574  INFO TableMetadata:69 - HHH000126: Indexes: [primary]
12:47:49,574  INFO SchemaUpdate:240 - HHH000232: Schema update complete
Hibernate:
insert
into
User
(name, age, id)
values
(?, ?, ?)