hibernate+mysql报错

说明:hibernate+mysql在已建立好的数据库中创建一个表时,发生如下报错,是怎么回事?
3:18:35,000 ERROR SchemaExport:202 - schema export unsuccessful 
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.io.EOFException STACKTRACE: java.io.EOFException 
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1934) 
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:483) 
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:992) 
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2568) 
at com.mysql.jdbc.Connection. <init>(Connection.java:1485) 
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266) 
at java.sql.DriverManager.getConnection(Unknown Source) 
at java.sql.DriverManager.getConnection(Unknown Source) 
at org.hibernate.connection.DriverManagerConnectionProvider.getConnection(DriverManagerConnectionProvider.java:110) 
at org.hibernate.tool.hbm2ddl.ManagedProviderConnectionHelper.prepare(ManagedProviderConnectionHelper.java:28) 
at org.hibernate.tool.hbm2ddl.SchemaExport.execute(SchemaExport.java:180) 
at org.hibernate.tool.hbm2ddl.SchemaExport.create(SchemaExport.java:133) 
at com.bjsxt.hibernate.ExportDB.main(ExportDB.java:15) 
** END NESTED EXCEPTION ** 
Last packet sent to the server was 16 ms ago. 
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:554) 
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:992) 
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2568) 
at com.mysql.jdbc.Connection. <init>(Connection.java:1485) 
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266) 
at java.sql.DriverManager.getConnection(Unknown Source) 
at java.sql.DriverManager.getConnection(Unknown Source) 
at org.hibernate.connection.DriverManagerConnectionProvider.getConnection(DriverManagerConnectionProvider.java:110) 
at org.hibernate.tool.hbm2ddl.ManagedProviderConnectionHelper.prepare(ManagedProviderConnectionHelper.java:28) 
at org.hibernate.tool.hbm2ddl.SchemaExport.execute(SchemaExport.java:180) 
at org.hibernate.tool.hbm2ddl.SchemaExport.create(SchemaExport.java:133) 
at com.bjsxt.hibernate.ExportDB.main(ExportDB.java:15)