Data Source Lookup fails

Question

The problem is that I get an class cast exception when doing a data source lookup. I need to know why this is happening and what can be done to avoid the exception. I have provided the following sections to document the run time environment:
1.     The stack trace from Jdeveloper
2.     The code that is run
3.     The web.xml file for the application
4.     The data source definition
Thanks in advance for the help!!!!
The stack trace from Jdeveloper :
Process exited.
C:\oracle\jdev903\jdk\bin\javaw.exe -ojvm -classpath C:\oracle\jdev903\j2ee\home\oc4j.jar -Dhttp.proxyHost=http -Dhttp.proxyPort=80 -Dhttp.nonProxyHosts= -Xverify:none -Doracle.j2ee.dont.use.memory.archive=true com.evermind.server.OC4JServer -config C:\oracle\jdev903\jdev\system9.0.3.1035\oc4j-config\server.xml
[Starting OC4J using the following ports: HTTP=8996, RMI=23891, JMS=9227.]
[waiting for the server to complete its initialization...]
m_dataSourceName = oracle.jdbc.pool.OracleConnectionPoolDataSource/default/jdbc/DBConn
Embedded OC4J startup time: 2574 ms.
Target URL -- http://172.17.36.54:8996/design-pcat-context-root/ProcessCatagory.jsp
Error creating the ORB :
Oracle9iAS (9.0.3.0.0) Containers for J2EE initialized
Entered doUpdates()
Trace ID: 1044899698135 Date:1/10/2003 Time: 11:54:58:135 AM
fsweb.util.FsException
Cause:
java.lang.ClassCastException: com.evermind.sql.OrionCMTDataSource
     void fsweb.product.ProcessCatalogCategoryThread.doUpdates()
          ProcessCatalogCategoryThread.java:54
     void ProcessCatagory.jspService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
          ProcessCatagory.jsp:10
     void oracle.jsp.runtime.HttpJsp.service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
          HttpJsp.java:139
     void oracle.jsp.runtimev2.JspPageTable.service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, java.lang.String)
          JspPageTable.java:317
     void oracle.jsp.runtimev2.JspServlet.internalService(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
          JspServlet.java:465
     void oracle.jsp.runtimev2.JspServlet.service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
          JspServlet.java:379
     void javax.servlet.http.HttpServlet.service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
          HttpServlet.java:853
     void com.evermind.server.http.ServletRequestDispatcher.invoke(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
          ServletRequestDispatcher.java:721
     void com.evermind.server.http.ServletRequestDispatcher.forwardInternal(javax.servlet.ServletRequest, javax.servlet.http.HttpServletResponse)
          ServletRequestDispatcher.java:306
     boolean com.evermind.server.http.HttpRequestHandler.processRequest(com.evermind.server.ApplicationServerThread, com.evermind.server.http.EvermindHttpServletRequest, com.evermind.server.http.EvermindHttpServletResponse, java.io.InputStream, java.io.OutputStream, boolean)
          HttpRequestHandler.java:767
     void com.evermind.server.http.HttpRequestHandler.run(java.lang.Thread)
          HttpRequestHandler.java:259
     void com.evermind.server.http.HttpRequestHandler.run()
          HttpRequestHandler.java:106
     void EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run()
          PooledExecutor.java:803
     void java.lang.Thread.run()
          Thread.java:484
The code that is run:
public void doUpdates()
Connection con = null;
OracleDataSource ds = null;
try
System.out.println("Entered doUpdates()");
Context ctx = new InitialContext();
ds = (OracleDataSource)ctx.lookup("jdbc/DBConn");
con = ds.getConnection();
ds = ds;
catch(Throwable t)
{ handleException(t); }
finally
if(con != null)
try { con.close(); }
catch(Throwable t) { handleException(t); }
System.out.println("Exit doUpdates()");
The web.xml file for the application:
<?xml version = '1.0' encoding = 'windows-1252'?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
<description>Empty web.xml file for Web Application</description>
<session-config>
<session-timeout>30</session-timeout>
</session-config>
<mime-mapping>
<extension>html</extension>
<mime-type>text/html</mime-type>
</mime-mapping>
<mime-mapping>
<extension>txt</extension>
<mime-type>text/plain</mime-type>
</mime-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
</web-app>
The data source definition:
Location:
C:\Program Files\Common Files\System\MAPI\1033\nt>C:\oracle\jdev903\jdev\system9
.0.3.1035\oc4j-config\data-sources.xml
Contents:
<?xml version="1.0" standalone='yes'?>
<!DOCTYPE data-sources PUBLIC "Orion data-sources" "http://xmlns.oracle.com/ias/dtds/data-sources.dtd">
<data-sources>
     <data-source
          class="com.evermind.sql.DriverManagerDataSource"
          name="OracleDS"
          location="jdbc/OracleCoreDS"
          xa-location="jdbc/xa/OracleXADS"
          ejb-location="jdbc/OracleDS"
          connection-driver="oracle.jdbc.driver.OracleDriver"
          username="scott"
          password="tiger"
          url="jdbc:oracle:thin:@localhost:5521:oracle"
          inactivity-timeout="30"
     />
<data-source
     class="oracle.jdbc.pool.OracleConnectionPoolDataSource"
     name="DBConn"
     location="jdbc/DBConn"
     xa-location="jdbc/xa/DBConn"
     ejb-location="jdbc/DBConn"
     connection-driver="oracle.jdbc.driver.OracleDriver"
     password="bc4j"
     username="bc4j"
     url="jdbc:oracle:thin:@nemesis:1521:fsweb"
     inactivity-timeout="30"
     min-connections="0"
     max-connections="10">
</data-source>
</data-sources>

Answer 1

The datasource defintion is for oc4j datasources whereas the code is trying to cast it to oracle datasource implementation. Use the datsource interface instead to get the connection. I.e
Change the lookup code to
javax.sql.DataSource ds = (javax.sal.DataSource)ctx.lookup(..);
ds.getConnection();
Dhiraj