MySql数据库异常

org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: 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:1913)
	at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2357)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2803)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:812)
	at com.mysql.jdbc.MysqlIO.nextRow(MysqlIO.java:1295)
	at com.mysql.jdbc.MysqlIO.readSingleRowSet(MysqlIO.java:2262)
	at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:439)
	at com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:1970)
	at com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:1387)
	at com.mysql.jdbc.ServerPreparedStatement.serverExecute(ServerPreparedStatement.java:1195)
	at com.mysql.jdbc.ServerPreparedStatement.executeInternal(ServerPreparedStatement.java:693)
	at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:794)
	at sun.reflect.GeneratedMethodAccessor107.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:45)
	at $Proxy43.execute(Unknown Source)
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:39)
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:55)
	at org.apache.ibatis.executor.BatchExecutor.doQuery(BatchExecutor.java:65)
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:238)
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:112)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:72)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:78)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:72)
	at org.apache.ibatis.binding.MapperMethod.executeForList(MapperMethod.java:100)
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:70)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:38)
	at $Proxy9.selectByExample(Unknown Source)
	at cn.eden.world.World$11.run(World.java:864)
	at java.util.TimerThread.mainLoop(Timer.java:512)
	at java.util.TimerThread.run(Timer.java:462)


** END NESTED EXCEPTION **



Last packet sent to the server was 3141437 ms ago.
### The error may involve cn.eden.dao.RoleMapper.selectByExample-Inline
### The error occurred while setting parameters
### Cause: 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:1913)
	at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2357)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2803)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:812)