ssm整合的時候總是報如下錯誤：

org.springframework.orm.hibernate5.HibernateJdbcException: JDBC exception on Hibernate data access: SQLException for SQL [n/a]; SQL state [null]; error code [0]; Unable to acquire JDBC Connection; nested exception is org.hibernate.exception.GenericJDBCException: Unable to acquire JDBC Connection

at org.springframework.orm.hibernate5.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:171)

at org.springframework.orm.hibernate5.HibernateTemplate.doExecute(HibernateTemplate.java:344)

at org.springframework.orm.hibernate5.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:309)

at org.springframework.orm.hibernate5.HibernateTemplate.find(HibernateTemplate.java:863)

at com.oracle.dao.impl.UserDaoImpl.getAllUser(UserDaoImpl.java:15)

at com.oracle.test.TestDemo.test(TestDemo.java:18)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)

at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:69)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:48)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)

at org.junit.runners.ParentRunner.run(ParentRunner.java:292)

at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)

at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

Caused by: org.hibernate.exception.GenericJDBCException: Unable to acquire JDBC Connection

at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47)

at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:109)

at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:95)

at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:90)

at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:112)

at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.connection(StatementPreparerImpl.java:47)

at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:146)

at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:172)

at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:148)

at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1928)

at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1897)

at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1875)

at org.hibernate.loader.Loader.doQuery(Loader.java:919)

at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:336)

at org.hibernate.loader.Loader.doList(Loader.java:2611)

at org.hibernate.loader.Loader.doList(Loader.java:2594)

at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2423)

at org.hibernate.loader.Loader.list(Loader.java:2418)

at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:501)

at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:371)

at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216)

at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1326)

at org.hibernate.internal.QueryImpl.list(QueryImpl.java:87)

at org.springframework.orm.hibernate5.HibernateTemplate$29.doInHibernate(HibernateTemplate.java:873)

at org.springframework.orm.hibernate5.HibernateTemplate$29.doInHibernate(HibernateTemplate.java:863)

at org.springframework.orm.hibernate5.HibernateTemplate.doExecute(HibernateTemplate.java:341)

... 27 more

Caused by: java.sql.SQLException: Connections could not be acquired from the underlying database!

at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)

at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:529)

at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)

at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)

at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:386)

at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:87)

... 49 more

Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.

at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319)

at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)

at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)

at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)

... 53 more

核對各種程式碼，配置檔案都沒有出錯，但就是報錯，各種煩惱。。。

最後發先資料庫的版本不對

   我剛開始用的是mysql-connector-java  版本是5.1.32

改成5.1.6就好了，記錄一下，哀悼一下浪費掉的時間。。。。。