hibernate 报错 Unable to load class[com.mysql.jdbc.Driver]

报错信息：

ERROR: HHH000231: Schema export unsuccessful

       org.hibernate.boot.registry.classloading.spi.ClassLoadingException: Unable to load class [com.mysql.jdbc.Driver]

at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:243)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.loadDriverIfPossible(DriverManagerConnectionProviderImpl.java:200)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildCreator(DriverManagerConnectionProviderImpl.java:156)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:95)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
at org.hibernate.tool.hbm2ddl.ManagedProviderConnectionHelper.prepare(ManagedProviderConnectionHelper.java:55)
at org.hibernate.tool.hbm2ddl.DatabaseExporter.<init>(DatabaseExporter.java:52)
at org.hibernate.tool.hbm2ddl.SchemaExport.execute(SchemaExport.java:368)
at org.hibernate.tool.hbm2ddl.SchemaExport.create(SchemaExport.java:305)
at org.hibernate.tool.hbm2ddl.SchemaExport.create(SchemaExport.java:294)
at com.bjsxt.hibernate.ExportDB.main(ExportDB.java:13)

Caused by: java.lang.ClassNotFoundException: Could not load requested class : com.mysql.jdbc.Driver
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl$AggregatedClassLoader.findClass(ClassLoaderServiceImpl.java:228)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
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:247)
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:240)
... 12 more
2015-1-21 13:47:50 org.hibernate.tool.hbm2ddl.SchemaExport execute

INFO: HHH000230: Schema export complete

解决方式：

在项目中添加上mysql的JDBC驱动包