strut problem

this my connectivity code using mysql server while runing the page it give this type error. what its means.

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;

import org.apache.struts.action.ActionForm;

import org.apache.struts.action.ActionForward;

import org.apache.struts.action.ActionMapping;

import java.sql.*;

public class TestDataSource extends Action

{

public ActionForward execute(

ActionMapping mapping,

ActionForm form,

HttpServletRequest request,

HttpServletResponse response) throws Exception{

javax.sql.DataSource dataSource;

java.sql.Connection myConnection=null;

try {

dataSource = getDataSource(request);

myConnection = dataSource.getConnection();

Statement stmt=myConnection.createStatement();

ResultSet rst=stmt.executeQuery("select * from test");

System.out.println("******************************************");

System.out.println("********Out Put from TestDataSource ******");

while(rst.next()){

System.out.println("User Name is: " + rst.getString("username"));

}

System.out.println("******************************************");

rst.close();

stmt.close();

// do what you wish with myConnection

} catch (SQLException sqle) {

System.out.println("sql"+sqle);

getServlet().log("Connection.process", sqle);

} finally {

//enclose this in a finally block to make

//sure the connection is closed

try {

myConnection.close();

} catch (SQLException e) {

System.out.println("e1"+e);

getServlet().log("Connection.close", e);

}

return mapping.findForward("success");

}

this my connectivity code using mysql server while runing the page it give this type error. what 's problem

javax.servlet.ServletException

at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:286)

at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)

at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:696)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:809)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:198)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:209)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:595)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:432)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:954)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:138)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:595)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:432)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:954)

at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2459)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:132)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:595)

at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:118)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:593)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:116)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:593)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:432)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:954)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:126)

at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:595)

at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:432)

at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:954)

at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:152)

at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)

at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)

at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)

at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)

at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)

at java.lang.Thread.run(Thread.java:595)

root cause

java.lang.NullPointerException

at TestDataSource.execute(TestDataSource.java:43)

at org.apache.struts.chain.commands.servlet.ExecuteAction.execute(ExecuteAction.java:58)

at org.apache.struts.chain.commands.AbstractExecuteAction.execute(AbstractExecuteAction.java:67)

at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)

at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)

at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)

at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)

at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)