title: Cannot create JDBC driver of class '' for connect URL 'null
body: <p>I am trying to configure JTA Transactions with Atomkios in Tomcat 5.5 for jndi support
      I am using spring,jpa+hybernate 
   when i m trying to access my database, i am getting the error like this</p>
  
  <pre><code>org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'
   org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:82)
   org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:572)
   org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:636)
   org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:665)
   org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:673)
   org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:713)
   com.evolvus.springsecurity.impl.CustomJdbcDaoImpl.loadUsersByUsername(CustomJdbcDaoImpl.java:78)
   org.springframework.security.core.userdetails.jdbc.JdbcDaoImpl.loadUserByUsername(JdbcDaoImpl.java:152)
   com.evolvus.springsecurity.impl.UsernamePasswordAuthenticationProvider.authenticate(UsernamePasswordAuthenticationProvider.java:27)
   org.springframework.security.authentication.ProviderManager.doAuthentication(ProviderManager.java:120)
   org.springframework.security.authentication.AbstractAuthenticationManager.authenticate(AbstractAuthenticationManager.java:48)
   com.evolvus.springsecurity.impl.LoginAuthenticationFilter.attemptAuthentication(LoginAuthenticationFilter.java:38)
   org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:200)
   org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
   org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
   org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
   org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
   org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
   org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:109)
   org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:355)
   org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:149)
   org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
   org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
   org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
   org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
  </code></pre>
  
  <p>my config.xml</p>
  
  <pre><code>&lt;beans: bean id="dataSource"
    class="org.springframework.jndi.JndiObjectFactoryBean" &gt;
    &lt;beans: property name="jndiName"&gt;
     &lt;beans:value&gt;java:comp/env/jdbc/welcome&lt;/beans:value&gt;
    &lt;/beans: property&gt;   
   &lt;/beans: bean&gt;
  and i configure data source in tomcat5.5/config/context.xml       
  
  
     &lt;Resource name="jdbc/welcome"  
       auth="Container" 
       type="com.atomikos.jdbc.AtomikosDataSourceBean" 
       factory="com.atomikos.tomcat.BeanFactory"
       uniqueResourceName="jdbc/myDB"
       xaDataSourceClassName="org.apache.derby.jdbc.EmbeddedXADataSource"
       maxPoolSize="3"
       minPoolSize="1"
       xaProperties.databaseName="payhub"
       xaProperties.url="jdbc\:mysql\://devserver\:3306/payhub" 
       /&gt;            
  </code></pre>
  
  <p>and in my application web.xml is</p>
  
  <pre><code>&lt;resource-ref&gt;
     &lt;description&gt;PaymentsDatabase&lt;/description&gt;
     &lt;res-ref-name&gt;jdbc/welcome&lt;/res-ref-name&gt;
     &lt;res-type&gt;javax.sql.DataSource&lt;/res-type&gt;
     &lt;res-auth&gt;Container&lt;/res-auth&gt;
     &lt;res-sharing-scope&gt;Shareable&lt;/res-sharing-scope&gt;
  &lt;/resource-ref&gt;
  </code></pre>
  
  <p>what mistake i have done here?</p>