why the following error occured in tomcat application?

[bhaskar sanghi]

why the following error occured in tomcat application?

org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class '
' for connect URL 'null'
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.jav
a:780)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:5
40)
at com.bob.hrms.DBUtil.getConnection(DBUtil.java:21)
at com.bob.hrms.master.RetClientMasterInfo.doGet(RetClientMasterInfo.java:22)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
FilterChain.java:237)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
ain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
va:214)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContext
Valve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
va:152)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137
)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:104)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118
)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:102)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
:109)
at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContex
t.java:104)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConne
ction(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.jav
a:683)
at java.lang.Thread.run(Unknown Source)
Caused by: java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getDriver(Unknown Source)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.jav
a:773)
... 29 more

[David O'Meara]

It doesn't look like your DataSource is configured correctly. Did you want to paste the settings and some (small) sample code showing how you're calling it?

Dave