Question

I have created a connection pool in Glassfish 3.1.2 called ‘userdb’ and a Datasource called ‘userdbresource’. While creating the datasource I have given the type as ‘javax.sql.Datasource’ in the admin console.

In my REST webservice I have written the following code

         DataSource ds = null;
        try
        {
        InitialContext ctx = new InitialContext();


            ds = (DataSource) ctx.lookup("userdbresource");
        }
        catch (NamingException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Connection con = (Connection) ds.getConnection();
        Statement stmt=con.createStatement();

I always get a ClassCast exception at Connection con = (Connection) ds.getConnection();

I have added the following to the web.xml

 <resource-ref>
        <res-ref-name>userdbresource</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
        <res-sharing-scope>Shareable</res-sharing-scope>
    </resource-ref>

But no change. I have tried to unwrap the connection after I look it up using com.mysql.jdbc.Connection. But no change.

The actual classcast exception in logs is

java.lang.ClassCastException: com.sun.gjc.spi.jdbc40.ConnectionHolder40 cannot be cast to com.mysql.jdbc.Connection

If anyone knows what changes I need to make to use the connection i retrieve from the pool please let me know!!

Thanks
Kavita

Answer 1

import java.sql.Connection; not jdbc connection thus you wont need any connection casting
and your datasource connection becomes

Connect con = ds.getConnection();