[SOLVED] SQLException: No suitable Driver Found for jdbc:oracle:thin:@//localhost:1521/orcl

I am trying to develop a Java EE application that connect to an Oracle database from eb service class but I encounter a

SQLException: No suitable driver found for jdbc:oracle:thin:@//localhost:1521/orcl

I have the ojdbc6.jar in the class path and I have also verified that this in the JBoss deployment folder.

My application EAR is composed of a WAR. What is wrong (root cause) with this? Please help.

Connection URL in persistence.xml:

> "jdbc:oracle:thin:@//localhost:1521/orcl"

Stack Trace:

16:06:32,687 WARN  [com.arjuna.ats.arjuna] (default-workqueue-1) ARJUNA012125: TwoPhaseCoordinator.beforeCompletion - failed for SynchronizationImple< 0:ffffc0a80106:-3e8b2d6f:5037338f:15, org.hibernate.engine.transaction.synchronization.internal.RegisteredSynchronization@4d1082 >: javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1361) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
    at 
Caused by: java.sql.SQLException: No suitable driver found for jdbc:oracle:thin:@//localhost:1521/orcl
    at java.sql.DriverManager.getConnection(DriverManager.java:602) [rt.jar:1.6.0_26]
    at java.sql.DriverManager.getConnection(DriverManager.java:154) [rt.jar:1.6.0_26]
    at org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:173) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:276) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:297) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    ... 70 more

16:06:32,796 ERROR [org.jboss.ejb3.invocation] (default-workqueue-1) JBAS014134: EJB Invocation failed on component CreditcardFacade for method public abstract void com.peter.ejb.CreditcardFacadeLocal.addCreditCard(com.peter.entity.Creditcard): javax.ejb.EJBTransactionRolledbackException: Transaction rolled back
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.handleEndTransactionException(CMTTxInterceptor.java:115) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.endTransaction(CMTTxInterceptor.java:95) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:232) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.required(CMTTxInterceptor.java:304) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:190) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ejb3.component.interceptors.CurrentInvocationContextInterceptor.processInvocation(CurrentInvocationContextInterceptor.java:41) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ejb3.component.interceptors.LoggingInterceptor.processInvocation(LoggingInterceptor.java:59) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ee.component.NamespaceContextInterceptor.processInvocation(NamespaceContextInterceptor.java:50) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ejb3.component.interceptors.AdditionalSetupInterceptor.processInvocation(AdditionalSetupInterceptor.java:32) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ee.component.TCCLInterceptor.processInvocation(TCCLInterceptor.java:45) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ee.component.ViewService$View.invoke(ViewService.java:165) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ee.component.ViewDescription$1.processInvocation(ViewDescription.java:173) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ee.component.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:72) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at com.peter.ejb.CreditcardFacadeLocal$$$view2.addCreditCard(Unknown Source) [classes:]
    com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.beforeCompletion(TwoPhaseCoordinator.java:273)
    at com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.end(TwoPhaseCoordinator.java:93)
    at com.arjuna.ats.arjuna.AtomicAction.commit(AtomicAction.java:164)
    at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1165)
    ... 46 more
Caused by: org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:131) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:304) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:169) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.extractPhysicalConnection(ConnectionProxyHandler.java:82) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation(ConnectionProxyHandler.java:138) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at $Proxy96.prepareStatement(Unknown Source)    at org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl.buildBatchStatement(AbstractBatchImpl.java:144) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl.getBatchStatement(AbstractBatchImpl.java:127) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2827) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3290) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:80) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:272) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:264) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:186) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:326) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:52) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1081) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:315) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.transaction.synchronization.internal.SynchronizationCallbackCoordinatorImpl.beforeCompletion(SynchronizationCallbackCoordinatorImpl.java:104) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    ... 52 more
Caused by: java.sql.SQLException: No suitable driver found for jdbc:oracle:thin:@//localhost:1521/orcl
    at java.sql.DriverManager.getConnection(DriverManager.java:602) [rt.jar:1.6.0_26]
    at java.sql.DriverManager.getConnection(DriverManager.java:154) [rt.jar:1.6.0_26]
    at org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:173) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:276) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:297) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    ... 70 more

16:06:32,953 WARNING [org.apache.cxf.phase.PhaseInterceptorChain] (default-workqueue-1) Application {http://service.peter.com/}CreditCardServiceService#{http://service.peter.com/}addCreditCard has thrown exception, unwinding now: org.apache.cxf.interceptor.Fault: Transaction rolled back
    at org.apache.cxf.service.invoker.AbstractInvoker.createFault(AbstractInvoker.java:155) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.jaxws.AbstractJAXWSMethodInvoker.createFault(AbstractJAXWSMethodInvoker.java:86) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:121) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.jaxws.JAXWSMethodInvoker.invoke(JAXWSMethodInvoker.java:61) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:75) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:58) [cxf-2.4.1.jar:2.4.1]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441) [rt.jar:1.6.0_26]
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) [rt.jar:1.6.0_26]
    at java.util.concurrent.FutureTask.run(FutureTask.java:138) [rt.jar:1.6.0_26]
    at org.apache.cxf.workqueue.SynchronousExecutor.execute(SynchronousExecutor.java:37) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:106) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:263) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.phase.PhaseInterceptorChain.resume(PhaseInterceptorChain.java:232) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.interceptor.OneWayProcessorInterceptor$1.run(OneWayProcessorInterceptor.java:109) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.workqueue.AutomaticWorkQueueImpl$2.run(AutomaticWorkQueueImpl.java:332) [cxf-2.4.1.jar:2.4.1]
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_26]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_26]
    at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_26]
Caused by: javax.ejb.EJBTransactionRolledbackException: Transaction rolled back
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.handleEndTransactionException(CMTTxInterceptor.java:115) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.endTransaction(CMTTxInterceptor.java:95) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:232) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.required(CMTTxInterceptor.java:304) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:190) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ejb3.component.interceptors.CurrentInvocationContextInterceptor.processInvocation(CurrentInvocationContextInterceptor.java:41) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ejb3.component.interceptors.LoggingInterceptor.processInvocation(LoggingInterceptor.java:59) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ee.component.NamespaceContextInterceptor.processInvocation(NamespaceContextInterceptor.java:50) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ejb3.component.interceptors.AdditionalSetupInterceptor.processInvocation(AdditionalSetupInterceptor.java:32) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ee.component.TCCLInterceptor.processInvocation(TCCLInterceptor.java:45) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ee.component.ViewService$View.invoke(ViewService.java:165) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.as.ee.component.ViewDescription$1.processInvocation(ViewDescription.java:173) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:288) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61) [jboss-invocation-1.1.1.Final.jar:1.1.1.Final]
    at org.jboss.as.ee.component.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:72) [jboss-as-ee-7.1.1.Final.jar:7.1.1.Final]
    at com.peter.ejb.CreditcardFacadeLocal$$$view2.addCreditCard(Unknown Source) [classes:]
    at com.peter.service.CreditCardService.addCreditCard(CreditCardService.java:56) [classes:]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.6.0_26]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [rt.jar:1.6.0_26]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [rt.jar:1.6.0_26]
    at java.lang.reflect.Method.invoke(Method.java:597) [rt.jar:1.6.0_26]
    at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:173) [cxf-2.4.1.jar:2.4.1]
    at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:89) [cxf-2.4.1.jar:2.4.1]
    ... 15 more
Caused by: javax.transaction.RollbackException: ARJUNA016053: Could not commit transaction.
    at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1177)
    at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:117)
    at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:75)
    at org.jboss.as.ejb3.tx.CMTTxInterceptor.endTransaction(CMTTxInterceptor.java:92) [jboss-as-ejb3-7.1.1.Final.jar:7.1.1.Final]
    ... 43 more
Caused by: javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1361) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1289) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1295) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.ejb.AbstractEntityManagerImpl$CallbackExceptionMapperImpl.mapManagedFlushFailure(AbstractEntityManagerImpl.java:1481) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.transaction.synchronization.internal.SynchronizationCallbackCoordinatorImpl.beforeCompletion(SynchronizationCallbackCoordinatorImpl.java:109) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.transaction.synchronization.internal.RegisteredSynchronization.beforeCompletion(RegisteredSynchronization.java:53) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple.beforeCompletion(SynchronizationImple.java:76)
    at com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.beforeCompletion(TwoPhaseCoordinator.java:273)
    at com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.end(TwoPhaseCoordinator.java:93)
    at com.arjuna.ats.arjuna.AtomicAction.commit(AtomicAction.java:164)
    at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1165)
    ... 46 more
Caused by: org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:131) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:304) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:169) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.extractPhysicalConnection(ConnectionProxyHandler.java:82) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation(ConnectionProxyHandler.java:138) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at $Proxy96.prepareStatement(Unknown Source)    at org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl.buildBatchStatement(AbstractBatchImpl.java:144) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl.getBatchStatement(AbstractBatchImpl.java:127) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2827) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3290) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:80) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:272) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:264) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:186) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:326) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:52) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1081) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:315) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.transaction.synchronization.internal.SynchronizationCallbackCoordinatorImpl.beforeCompletion(SynchronizationCallbackCoordinatorImpl.java:104) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    ... 52 more
Caused by: java.sql.SQLException: No suitable driver found for jdbc:oracle:thin:@//localhost:1521/orcl
    at java.sql.DriverManager.getConnection(DriverManager.java:602) [rt.jar:1.6.0_26]
    at java.sql.DriverManager.getConnection(DriverManager.java:154) [rt.jar:1.6.0_26]
    at org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:173) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:276) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:297) [hibernate-core-4.0.1.Final.jar:4.0.1.Final]
    ... 70 more

Oracle Database Version: 11.2.0.

Does driver version need to match with database version?

EDIT:

How to trace which file path the program load the driver from? This enhance me to find the root cause. Thanks.
How to enable the ojdbc6-g logging? I'm tried follow this Oracle_JDBC but I do not know how to complete it. How to set the java system property globally? I know that environment variable may not a good choice. Any other idea? I just want to add -Doracle.jdbc.Trace=true and -Djava.util.logging.config.file to jvm creation when using this java. Is it set up oracle database during the startup?
How to enable hibernate logging?
I'm using Hibernate-4.1.1 and JBoss 7.1.

Please help.

Thanks.