关于集成JPA时问题

我在集成JPA用junit测试时出现以下问题，该如何解决呢？谢谢您的回复2009-07-24 10:22:31,937 ERROR [org.hibernate.util.JDBCExceptionReporter] - Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.net.SocketException
MESSAGE: Connection resetSTACKTRACE:java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:168)
at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:113)
at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:160)
at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:188)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1994)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2411)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3277)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3206)
at com.mysql.jdbc.Statement.executeQuery(Statement.java:1232)
at com.mysql.jdbc.DatabaseMetaData$2.forEach(DatabaseMetaData.java:2390)
at com.mysql.jdbc.DatabaseMetaData$IterateBlock.doForAll(DatabaseMetaData.java:76)
at com.mysql.jdbc.DatabaseMetaData.getColumns(DatabaseMetaData.java:2264)
at org.hibernate.tool.hbm2ddl.TableMetadata.initColumns(TableMetadata.java:146)
at org.hibernate.tool.hbm2ddl.TableMetadata.<init>(TableMetadata.java:32)
at org.hibernate.tool.hbm2ddl.DatabaseMetadata.getTableMetadata(DatabaseMetadata.java:90)
at org.hibernate.cfg.Configuration.generateSchemaUpdateScript(Configuration.java:954)
at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:140)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:314)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1300)
** END NESTED EXCEPTION **Last packet sent to the server was 2234 ms ago.
2009-07-24 10:22:32,031 ERROR [org.hibernate.tool.hbm2ddl.SchemaUpdate] - could not complete schema update
org.hibernate.exception.JDBCConnectionException: could not get table metadata: ProductType
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29)
at org.hibernate.tool.hbm2ddl.DatabaseMetadata.getTableMetadata(DatabaseMetadata.java:105)
at org.hibernate.cfg.Configuration.generateSchemaUpdateScript(Configuration.java:954)
at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:140)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:314)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1300)
at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:859)
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:669)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:126)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:60)
at junit.test.ProductTest.runtest(ProductTest.java:22)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:38)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: 
2009-07-24 10:22:32,218 ERROR [org.hibernate.transaction.JDBCTransaction] - JDBC begin failed
com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException: Connection.close() has already been called. Invalid operation in this state.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:888)
at com.mysql.jdbc.Connection.getMutex(Connection.java:3755)
at com.mysql.jdbc.Connection.setAutoCommit(Connection.java:5412)
at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:63)
at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1326)
at org.hibernate.ejb.TransactionImpl.begin(TransactionImpl.java:38)
at junit.test.ProductTest.runtest(ProductTest.java:27)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.junit.internal.runners.TestMethodRunner.executeMethodBody(TestMethodRunner.java:99)
at org.junit.internal.runners.TestMethodRunner.runUnprotected(TestMethodRunner.java:81)
at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)
at org.junit.internal.runners.TestMethodRunner.runMethod(TestMethodRunner.java:75)
at org.junit.internal.runners.TestMethodRunner.run(TestMethodRunner.java:45)
at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:71)
at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:35)
at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42)
at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)
at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:38)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)2009-07-24 10:22:32,265 INFO [org.hibernate.impl.SessionFactoryImpl] - closing
2009-07-24 10:22:32,265 INFO [org.hibernate.connection.DriverManagerConnectionProvider] - cleaning up connection pool: jdbc:mysql://localhost:3306/itcast?useUnicode=true&characterEncoding=gbk