初学者有关问题 现在在接触hibernate（找不到驱动 设置的时候测试成功啊）

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).log4j:WARN Please initialize the log4j system properly.Exception in thread "main" org.hibernate.HibernateException: JDBC Driver class not found: com.microsoft.sqlserver.jdbc.SQLServerDriver    at org.hibernate.connection.DriverManagerConnectionProvider.configure(DriverManagerConnectionProvider.java:89)    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:137)    at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:79)    at org.hibernate.cfg.SettingsFactory.createConnectionProvider(SettingsFactory.java:425)    at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:89)    at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2119)    at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2115)    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1339)    at test.test.main(test.java:31)Caused by: java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver    at java.net.URLClassLoader$1.run(URLClassLoader.java:200)    at java.security.AccessController.doPrivileged(Native Method)    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)    at java.lang.Class.forName0(Native Method)    at java.lang.Class.forName(Class.java:169)    at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:192)    at org.hibernate.connection.DriverManagerConnectionProvider.configure(DriverManagerConnectionProvider.java:84)    ... 8 more