problem exception in Tomcat 5.0.19

[Carlos Alberto Peláez Ayala <ca...@cuao.edu.co>]

I found this problem in my portal.log file. Something can tell me how i can
solve this ?.
Thanks.

EXCEPTION: org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC
dri
ver of class '' for connect URL 'null', cause: No suitable driver
org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of
class '' for connect URL 'null', cause: 
java.sql.SQLException: No suitable driver
        at java.sql.DriverManager.getDriver(DriverManager.java:243)
        at
org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.jav
a:743)
        at
org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:5
18)
        at
org.jasig.portal.RDBMServices.getConnection(RDBMServices.java:255)
        at
org.jasig.portal.RDBMServices.getConnection(RDBMServices.java:288)
        at
org.jasig.portal.RDBMUserLayoutStore.getStructureStylesheetUserPreferences(R
DBMUserLayoutStore.java:949)
        at
org.jasig.portal.RDBMUserLayoutStore.getUserPreferences(RDBMUserLayoutStore.
java:2953)
        at
org.jasig.portal.UserPreferencesManager.<init>(UserPreferencesManager.java:1
39)
        at org.jasig.portal.UserInstance.writeContent(UserInstance.java:149)
        at
org.jasig.portal.PortalSessionManager.doGet(PortalSessionManager.java:246)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
        at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:284)
        at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:204)
        at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:257)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:151)
        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
        at
org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContext
Valve.java:245)
        at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:199)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:151)
        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
        at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:184
)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:151)
        at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:164
)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:149)
        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
        at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:156)
        at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:151)
        at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:567)
        at
org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:972)
        at
org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:206)
        at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:833)
        at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
ction(Http11Protocol.java:732)
        at
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:619)
        at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:688)
        at java.lang.Thread.run(Thread.java:534)