jdbc连接oracle数据库11.1失败

使用weblogic连接oracle database，选择thin驱动，jdbc:oracle:thin:@bej301137.cn.oracle.com:1521/orcl.cn.oracle.com
总是报错：连接测试失败。
IO Error: The Network Adapter could not establish the connection<br/>oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:482)<br/>oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:679)<br/>oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:238)<br/>oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:34)<br/>oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:567)<br/>weblogic.jdbc.common.internal.DataSourceUtil.testConnection(DataSourceUtil.java:298)<br/>com.bea.console.utils.jdbc.JDBCUtils.testConnection(JDBCUtils.java:734)<br/>com.bea.console.actions.jdbc.datasources.createjdbcdatasource.CreateJDBCDataSource.testConnectionConfiguration(CreateJDBCDataSource.java:472)<br/>sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)<br/>sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)<br/>sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)<br/>java.lang.reflect.Method.invoke(Method.java:597)<br/>org.apache.beehive.netui.pageflow.FlowController.invokeActionMethod(FlowController.java:870)<br/>org.apache.beehive.netui.pageflow.FlowController.getActionMethodForward(FlowController.java:809)<br/>org.apache.beehive.netui.pageflow.FlowController.internalExecute(FlowController.java:478)<br/>org.apache.beehive.netui.pageflow.PageFlowController.internalExecute(PageFlowController.java:306)<br/>org.apache.beehive.netui.pageflow.FlowController.execute(FlowController.java:336)<br/>org.apache.beehive.netui.pageflow.internal.FlowControllerAction.execute(FlowControllerAction.java:52)<br/>org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)<br/>org.apache.beehive.netui.pageflow.PageFlowRequestProcessor.access$201(PageFlowRequestProcessor.java:97)<br/>...请问是为什么呢，需要安装JDBC驱动吗，可是貌似weblogic已经默认安装了一些驱动。