hibernate抛出异常问题
在运行测试用的HiberTest类时抛出如下异常，我找了很长时间还是没能解决，外国论坛也有这种，但是他们的方法有的我试过，还是不行。有的看不懂，请高手们帮帮忙，能解决的话，我有分再加分。
Exception   in   thread   "main "   java.lang.ExceptionInInitializerError
at   com.ctcmc.hibernate.HibernateUtil. <clinit> (HibernateUtil.java:11)
at   com.ctcmc.hibernate.DAOImp.createStu(DAOImp.java:23)
at   com.ctcmc.hibernate.HiberTest.main(HiberTest.java:16)
Caused   by:   org.apache.commons.logging.LogConfigurationException:   org.apache.commons.logging.LogConfigurationException:   java.lang.NullPointerException   (Caused   by   java.lang.NullPointerException)   (Caused   by   org.apache.commons.logging.LogConfigurationException:   java.lang.NullPointerException   (Caused   by   java.lang.NullPointerException))
at   org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:543)
at   org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:235)
at   org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:209)
at   org.apache.commons.logging.LogFactory.getLog(LogFactory.java:351)
at   org.hibernate.cfg.Configuration. <clinit> (Configuration.java:116)
...   3   more
Caused   by:   org.apache.commons.logging.LogConfigurationException:   java.lang.NullPointerException   (Caused   by   java.lang.NullPointerException)
at   org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:397)
at   org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:529)
...   7   more
Caused   by:   java.lang.NullPointerException
at   org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:374)
...   8   more
hibernate.cfg.xml文件内容：

<hibernate-configuration>
<session-factory>
<!--   local   connection   properties   -->
<property   name= "hibernate.connection.url ">
jdbc:microsoft:sqlserver://192.168.0.1:1433;databasename=test
</property>
<property   name= "hibernate.connection.driver_class ">
com.microsoft.jdbc.sqlserver.SQLServerDriver
</property>
<property   name= "hibernate.connection.username "> sa </property>
<property   name= "hibernate.connection.password "> fhwlcatv </property>
<!--   property   name= "hibernate.connection.pool_size "> </property   -->
<!--   dialect   for   Microsoft   SQL   Server   -->
<property   name= "dialect ">
org.hibernate.dialect.SQLServerDialect
</property>
<property   name= "hibernate.show_sql "> true </property>
<property   name= "hibernate.transaction.factory_class ">
org.hibernate.transaction.JDBCTransactionFactory
</property>
<mapping   resource= "com/c