最近公司项目里需要使用到将所有执行的sql打出日志，放在一个文件下。公司一大神级人物给解决了，刚刚花了点时间给研究了一下。
他用的就是p6spy，其实也没做多少工作。主要的工作p6spy都已经做过了。
p6spy我的理解就是：p6spy将应用的数据源给劫持了，应用操作数据库其实在调用p6spy的数据源，p6spy劫持到需要执行的sql或者hql之类的语句之后，他自己去调用一个realDatasource，再去操作数据库，只要劫持到那些sql之后，能干的事情就很多了。
p6spy 可以输出日志到文件中、控制台、或者传递给 Log4j，而且还能配搭 SQL Profiler 或 IronTrackSQL 图形化监控 SQL 语句，监测到哪些语句的执行是耗时的，逐个优化。关于与 SQL Profiler 或 IronTrackSQL 的配合使用可参数文件的链接。
p6spy在sourceforge上下载：[p6spy][]
[p6spy]: http://sourceforge.net/projects/p6spy/?source=dlp
p6spy的配置：
p6spy.jar放入应用的classpath下
修改连接池或者连接配置的jdbc的驱动为p6spy所提供的驱动，
com.p6spy.engine.spy.P6SpyDriver在单独的Hibernate的应用中，数据库驱动配置在hibernate.cfg.xml里面,所以我需要配置文件中的connection.driver_class属性从oracle.jdbc.driver.OracleDriver改为com.p6spy.engine.spy.P6SpyDriver其他的用户名密码等等配置信息全部不用修改.在web程序中，配置的连接池部分，也只需要修改jdbc-driver的配置即可。
Hibernate.cfg.xml:
<session-factory> <!-- 在这里改成p6spy提供的数据源 --> <property name="connection.driver_class">com.p6spy.engine.spy.P6SpyDriver</property> <property name="connection.url">jdbc:oracle:thin:@localhost:1521:orcl</property> <property name="connection.username">scott</property> <property name="connection.password">tiger</property> <property name="connection.pool_size">1</property> <property name="dialect">org.hibernate.dialect.Oracle9Dialect</property> <property name="current_session_context_class">thread</property> <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> <property name="show_sql">true</property> <property name="hbm2ddl.auto">false</property> <property name="hibernate.jdbc.batch_size">0</property> </session-factory>修改
spy.properties并将其放到classpath下：################################################################# # MODULES # # # # Modules provide the P6Spy functionality. If a module, such # # as module_log is commented out, that functionality will not # # be available. If it is not commented out (if it is active), # # the functionality will be active. # # # # Values set in Modules cannot be reloaded using the # # reloadproperties variable. Once they are loaded, they remain # # in memory until the application is restarted. # # # ################################################################# #第一：module.log的属性必须配置，如果不配置，P6SPY将不起任何作用，典型配置： module.log=com.p6spy.engine.logging.P6LogFactory #module.outage=com.p6spy.engine.outage.P6OutageFactory ################################################################# # REALDRIVER(s) # # # # In your application server configuration file you replace the # # "real driver" name with com.p6spy.engine.P6SpyDriver. This is # # where you put the name of your real driver P6Spy can find and # # register your real driver to do the database work. # # # # If your application uses several drivers specify them in # # realdriver2, realdriver3. See the documentation for more # # details. # # # # Values set in REALDRIVER(s) cannot be reloaded using the # # reloadproperties variable. Once they are loaded, they remain # # in memory until the application is restarted. # # # ################################################################# #第二：数据库驱动配置，你懂的，不多说了 # oracle driver # realdriver=oracle.jdbc.driver.OracleDriver # mysql Connector/J driver # realdriver=com.mysql.jdbc.Driver # informix driver # realdriver=com.informix.jdbc.IfxDriver # ibm db2 driver # realdriver=COM.ibm.db2.jdbc.net.DB2Driver # the mysql open source driver realdriver=org.gjt.mm.mysql.Driver #specifies another driver to use realdriver2= #specifies a third driver to use realdriver3= #第三：appender配置，一般分为三种 #specifies the appender to use for logging #appender=com.p6spy.engine.logging.appender.Log4jLogger #控制台 #appender=com.p6spy.engine.logging.appender.StdoutLogger appender=com.p6spy.engine.logging.appender.FileLogger # name of logfile to use, note Windows users should make sure to use forward slashes in their pathname (e:/test/spy.log) (used for file logger only) #日志文件存放路径及文件名 logfile = spy.log # append to the p6spy log file. if this is set to false the # log file is truncated every time. (file logger only) append=true #The following are for log4j logging only log4j.appender.STDOUT=org.apache.log4j.ConsoleAppender log4j.appender.STDOUT.layout=org.apache.log4j.PatternLayout log4j.appender.STDOUT.layout.ConversionPattern=p6spy - %m%n log4j.logger.p6spy=INFO,STDOUT
