项目由tomcat转到was6.1.在连接oracle数据库时，有时是正常的，有时会出现java.sql.SQLException: Io 异常: The Network Adapter could not establish the connection。
tomcat下一切正常，在网上找了好久也没找到答案，url正确，防火墙全部关闭，监听也有，而且在同一环境下tomcat启动，访问不会出现错误。
跪求大侠解决！
错误代码：
[12-5-10 16:08:01:652 GMT] 000000a0 PhaseIntercep W java.lang.Throwable <init> Application has thrown exception, unwinding now
org.apache.cxf.interceptor.Fault: Could not open Hibernate Session for transaction; nested exception is org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.apache.cxf.service.invoker.AbstractInvoker.createFault(AbstractInvoker.java:148)
at org.apache.cxf.jaxws.AbstractJAXWSMethodInvoker.createFault(AbstractJAXWSMethodInvoker.java:83)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:114)
at org.apache.cxf.jaxws.JAXWSMethodInvoker.invoke(JAXWSMethodInvoker.java:55)
at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:68)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:58)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:432)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:284)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at org.apache.cxf.workqueue.SynchronousExecutor.execute(SynchronousExecutor.java:37)
at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:98)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:236)
at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:104)
at org.apache.cxf.transport.servlet.ServletDestination.invoke(ServletDestination.java:98)
at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:392)
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:170)
at org.apache.cxf.transport.servlet.AbstractCXFServlet.invoke(AbstractCXFServlet.java:142)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doPost(AbstractHTTPServlet.java:45)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:763)
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:101)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:966)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:907)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:145)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:190)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:130)
at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)