When Jboss 5 and Oracle 11g jdbc driver integrated, org.jboss.util.NestedSQLException occurs!

OS : CentOS Linux 5.5

JDK : JDK 1.5

JBoss : JBoss 5.0.0.GA

DB : 예) Oracle 11g

I put ojdbc5.jar file into jboss-5.0.0.GA/common/lib folder and set oracle-ds.xml file like below

<datasources>

  <local-tx-datasource>

    <jndi-name>OracleDS</jndi-name>

    <connection-url>jdbc:oracle:thin:@localhost:1521:orcl</connection-url>

    <driver-class>oracle.jdbc.driver.OracleDriver</driver-class>

    <user-name>scott</user-name>

    <password>tiger</password>

    <min-pool-size>2</min-pool-size>

    <max-pool-size>5</max-pool-size>

    <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.OracleExceptionSorter</exception-sorter-class-name>

    <metadata>

       <type-mapping>Oracle11g</type-mapping>

    </metadata>

  </local-tx-datasource>

</datasources>

In JSP file, code is

ctx=new initialContext();

ds=(DataSource)ctx.lookup("java:/OracleDS");

con=ds.getConnection();

However, code does net generate connection objects.In Eclipse Console, messages are

10:26:07,923 ERROR [STDERR] org.jboss.util.NestedSQLException: Could not create connection; - nested throwable: (java.sql.SQLException: IO Exception: The Network Adapter could not establish the connection); - nested throwable: (org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (java.sql.SQLException: IO Exception: The Network Adapter could not establish the connection))

10:26:07,923 ERROR [STDERR]     at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:95)

10:26:07,923 ERROR [STDERR]     at org.apache.jsp.oracletest_jsp._jspService(oracletest_jsp.java:92)

10:26:07,923 ERROR [STDERR]     at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)...

I need your advise. Best Regards..