8 Replies Latest reply on May 24, 2008 12:38 AM by unni s

    Implementing custom datasource

    unni s Newbie

      I am implementing my jdbc connections using datasource. Whenever I do a lookup for datasource in the JNDI, i gets the instance of following class

      org.jboss.resource.adapter.jdbc.WrapperDataSource

      and ds.getConncetion() will give the object of WrappedConnection

      Is there a way to change this using configuration. like when i am doing data source look up I should get the instance of CustomDatasource. What ever jboss implements using WrapperDataSource, I will implement in my Custom datasource also ( With some extra things ) .

      Any pointers or help is appreciated

      Thanls & Regards

      Unni

        • 1. Re: Implementing custom datasource
          Vicky Kak Master

           

          "unnis" wrote:

          Is there a way to change this using configuration. like when i am doing data source look up I should get the instance of CustomDatasource. What ever jboss implements using WrapperDataSource, I will implement in my Custom datasource also ( With some extra things ) .

          Any pointers or help is appreciated

          Thanls & Regards

          Unni


          You would need to develop your own custom JDBC resource adapter which you should not be doing unless you have a valid reason to do so .

          Go and grab Jboss Admin book and read the JCA chapter , you can find out the sample outbound JCA application there .
          http://docs.jboss.org/jbossas/jboss4guide/r5/html/ch7.chapt.html

          Also google a bit you should be able to see the sample jca/jdbc resource adapter implementation somewhere.







          • 2. Re: Implementing custom datasource
            unni s Newbie

            Dear vicky,

            Thanks for your reply.

            Jboss is already providing JDBC resource adaptor called "jboss-local-jdbc.rar".

            What might be the following properties in jboss-local-jdbc.rar/META-INF/ra.xml


            <managedconnectionfactory-class>org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory</managedconnectionfactory-class>
            <connectionfactory-interface>javax.sql.DataSource</connectionfactory-interface>
            <connectionfactory-impl-class>org.jboss.resource.adapter.jdbc.WrapperDataSource</connectionfactory-impl-class>
            <connection-interface>java.sql.Connection</connection-interface>
            <connection-impl-class>org.jboss.resource.adapter.jdbc.WrappedConnection</connection-impl-class>


            can we change the property "connectionfactory-impl-class" and rebuild the rar

            Thanks & Regards

            unnis


            • 3. Re: Implementing custom datasource
              Adrian Brock Master

               

              "unnis" wrote:

              can we change the property "connectionfactory-impl-class" and rebuild the rar

              Thanks & Regards

              unnis


              No you build your own rar and deploy it as a tx-connection-factory
              instead of a local-tx-datasource.

              I suspect your CustomDataSource isn't really a resource adapter
              (since you don't have implementations of the other required classes).

              In which case you should ignore the -ds.xml and use an MBean to
              instantiate and bind your datasource into JNDI.

              But that's not really a topic for this forum, it's not JCA if there's no resource adapter.

              • 4. Re: Implementing custom datasource
                Adrian Brock Master

                 

                "adrian@jboss.org" wrote:
                "unnis" wrote:

                can we change the property "connectionfactory-impl-class" and rebuild the rar

                Thanks & Regards

                unnis


                No you build your own rar and deploy it as a tx-connection-factory
                instead of a local-tx-datasource.


                local-tx-datasource is just a tx-connection-factory with some hardwiring
                to use our rar and easier xml config of the config properties.

                • 5. Re: Implementing custom datasource
                  unni s Newbie

                  Dear adrian,

                  Thanks for the reply. My exact requirement is the following.

                  Based on the user profile I need to connect multiple databases. All of my databases will reside in same mysql server and is having same structure.I can't use multiple datasource and multiple connection pool, since the number of databses is more. So my plan is to have a single datasource and swich the database using setCatalog() jdbc method.

                  My application does the data source lookup in the following ways

                  1) Direct JNDI lookup in EJB
                  2) Using Hibernate
                  3) Using KODO-JDO

                  In all the above cases I am using same JNDI name ( mySqlDS) .

                  How can I achive this ???

                  I feel that database switching has to be done before giving the connection to the client ( EJB/Hibernate/jdo) . So this has to be done at DataSource level so that ds.getConnection() should return the proper connection with proper catalog set.


                  If I am using CustomDataSource , Inside CustomDataSource is there a way to access values from EJbContext ???

                  Thanks & Regards

                  unnis

                  • 6. Re: Implementing custom datasource
                    unni s Newbie

                    Hello:

                    Am I missing anything obvious or haven't followed any standards in posting the question ?
                    thanks and regards,


                    unnis

                    • 7. Re: Implementing custom datasource
                      Adrian Brock Master

                      If the connections are not equivalent then they are not a pool.

                      However there is something called "re-authentication support" in JCA
                      which our datasources don't currently implement
                      http://jira.jboss.org/jira/browse/JBAS-1429

                      • 8. Re: Implementing custom datasource
                        unni s Newbie

                         

                        If the connections are not equivalent then they are not a pool.



                        The connections are equivalent , URL, user name , password are same only. only thing that i want to switch the database .


                        Thanks & regards

                        unnis