Problem JNDI DataSource - no Connection on MySQL DB

[in...@projektinter.net]

Hi,

trying to connect to my MySQL DB via JNDI but I do not get a Connection in detail:
Using Tomcat 4.03, Linux Suse 7.3, MySQL 3.23.14.

I try to connect with this code:
.
.
.
 Context initCtx = new InitialContext();
    if (initCtx == null) throw new JspException("No Context available for DataSource, can't get connetion");
    Context envCtx = (Context) initCtx.lookup("java:comp/env");
    if (envCtx == null) throw new SQLException("No DataSource availale for Connection (envCtx == null)");
      ds = (DataSource)envCtx.lookup("jdbc/wwa-mDB");
    if (ds == null) throw new SQLException("No DataSource availale for Connection (ds == null) " + ds + "envCtx = " + envCtx);
       verbin = ds.getConnection();
       verbin.setReadOnly(true);
    stmt = verbin.createStatement(); 
.
.
an the problem ist that ds == null (envCtx == org.apache.naming.NamingContext@452200).
I am wondering why I cannot connect the DB. Before I connectet directly like:

Class.forName("org.gjt.mm.mysql.Driver").newInstance(); 
String url = "jdbc:mysql://localhost:3306/wwa-m01?user=user&password=pwd";

And it worked just fine.

My web.xml-File lookes like:
<resource-ref>
 <description>
    Resource reference to a factory for java.sql.Connection
    instances that may be used for talking to a particular
    database that is configured in the server.xml file.
  </description>
  <res-ref-name>jdbc/wwa-mDB</res-ref-name>
  <res-type>javax.sql.DataSource</res-type>
  <res-auth>Container</res-auth>
</resource-ref>


und the server.xml:
<Resource name="jdbc/wwa-mDB" auth="Container"
                    type="javax.sql.DataSource"/>
          <ResourceParams name="jdbc/wwa-mDB">
            <parameter><name>user</name><value>user</value></parameter>
            <parameter><name>password</name><value>pwd</value></parameter>
            <parameter><name>driverClassName</name><value>org.gjt.mm.mysql.Driver</value></parameter>
            <parameter><name>url</name><value>jdbc:mysql://localhost:3306/wwa_m01</value></parameter>
          </ResourceParams>

Can you give me any assistance on how to find out what is wrong with my Connection an how I can find out about that?

Thanks a lot!

Rainer