Java Spring Web App - Database Access Exception

Hi iv been struggling with this error for some time and really cant figure out why its occurring , i have a web application that uses springs simpleJdbctemplate to access a database i can use this locally and it has been tested but when i deploy the application jersey has some problems running the queries on the server this is the stacktrace from the tomcat logs

10-Jan-2011 21:15:28 com.sun.jersey.spi.container.ContainerResponse mapMappableContainerException
SEVERE: The RuntimeException could not be mapped to a response, re-throwing to the HTTP container
java.lang.NullPointerException
    at example.jersey.spring.dao.testDAO.getUsers(testDAO.java:20)
    at example.jersey.spring.MyResource.getIt(MyResource.java:23)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$TypeOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:168)
    at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:70)
    at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:279)
    at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:86)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:136)
    at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.j开发者_如何学编程ava:74)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1357)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1289)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1239)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1229)
    at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:420)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:497)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:684)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
    at java.lang.Thread.run(Unknown Source)

This is my resource

 @GET 
    @Produces("text/plain")
    public String getIt() {
        return "the number of users are " +db.getUsers();
    }

TestDAO.java

 SimpleJdbcTemplate simpleJdbcTemplate ;

        public void setDataSource(final DataSource dataSource) {
            this.simpleJdbcTemplate = new SimpleJdbcTemplate(dataSource);
        }

applicationContext.xml

  <bean id="dataSource" destroy-method="close" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
    </bean>

<bean id="testDAO" class="com.example.testDAOimpl">
        <property name="dataSource" ref="dataSource"/>
    </bean>

running locally in eclipse the db.getusers returns - the correct value of 1 so i cant understand why it doesnt work when deployed

Any help greatly appreciated

(Seems to be no real difference from the local set up and the server set up ) if anyone has encountered this anyhelp is much appreciated)

Thanks Chris

Not sure if this is your problem. But I was facing a similar issue. And what ended up happening is I was missing the MimeMultipart.class on my class path in my server code. Jersey was unable to find the class, and therefore unable to map the server request properly. Strangest thing was I never saw any kind of error message on the server side indicating a class not found.

Assuming you use a bean factory, do something like this to get it from spring:

BeanFactoryLocator beanFactoryLocator = SingletonBeanFactoryLocator.getInstance();
BeanFactoryReference beanFactoryReference = beanFactoryLocator.useBeanFactory("ctx");

testDAOimpl myDao = (testDAOimpl)beanFactoryReference.getFactory().getBean("testDAO");