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  1. Jetspeed 2 (Retired)
  2. JS2-326

Problem with LocalDataSourceConnectionFactory

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Details

    • Bug
    • Status: Closed
    • Major
    • Resolution: Fixed
    • 2.0-M4
    • 2.0-M4
    • Persistence and DAO
    • None
    • JBoss/HSQL

    Description

      I'm trying to get the JBoss security module back to work after the changes made in the recent weeks. The really big problem is that OJB.properties has changed and uses LocalDataSourceConnectionFactory now:

      ConnectionFactoryClass=org.springframework.orm.ojb.support.LocalDataSourceConnectionFactory

      This is rather fatal (at least until we get and use dbojb 1.1). Let me briefly explain why.

      There is a problem when using dbojb in a library or framework or simply anything that is meant to integrate with other code. The problem is the usage of static classes and singletons for configuration in dbojb. It implies that you can configure only a single instance of OJB (within the same classloader). The issue is known and to be resolved with dbojb 1.1 (http://nagoya.apache.org/eyebrowse/ReadMsg?listName=ojb-dev@db.apache.org&msgNo=11150).

      Jetspeed uses dbojb and is thus "in control" of dbojb. Anything that wants to use dbojb too must either live with the configuration provided by Jetspeed (at least the parts Jetspeed relies on, some things can certainly be changed in OJB.properties without breaking Jetspeed) or somehow use dbojb in its own classloader (not that easily chievable in the J2EE environment).

      The JBoss security module for Jetspeed is provided by an MBean in the form of a "server extension". Obviously, this MBean cannot depend on the deployment of some WebApplication (Jetspeed) and therefore the MBean
      needs its own "instance" of dbojb. Up to M3, this has been no problem because the MBean simply used the dbojb classes with the configuration information also used by Jetspeed and thus the Jetspeed web applications never "noticed" that it wasn't really them that instantiated dbojb (or vice vera, whoever caused loading first). The MBean augmented the dbojb configuration, however, by specifying a new JDBC connection description (using the API). This is necessary because the datasource used by the web application is not available outside the web application. This has been no problem, the JDBC connection description has simply been registered in the dbojb ConnectionRepository as another connection that uses the "global" JNDI entry for the data source.

      All this has worked fine up to M3 because the ConnectionRepository is used to lookup connections by the ConnectionFactoryManagedImpl. But currently, the LocalDataSourceConnectionFactory is used in place of the ConnectionFactoryManagedImpl. This means that connection descriptions are no longer looked up in the ConnectionRespository but must rather exist in a specific Spring BeanContext (set once). Of course, this is the BeanContext used (and set) by Jetspeed and this context is not accessible outside Jetspeed, i.e. it is not accessible by the MBean.

      What has been achieved by using LocalDataSourceConnectionFactory? IMO very little: the connection used by Jetspeed is now configured using a Spring controlled JavaBean instead of providing the information in repository_database.xml. What has been lost? A lot: the possibility to sustain (within the ojb configuration restrictions of Jetspeed) other data base connections in parallel and thus use dbojb for more object persistence tasks in parallel to Jetspeed.

      I therefore propose to revert this change. Configuration of the db connection in a JavaBean could still be done (even better) by writing a JavaBean that creates the JDBC connection description in the ConnectionRepository. Most of the code can be taken from JetspeedSecurityService. boot/datasource.xml would instantiate this JavaBean and thus create the entry in the ConnectionRepository (it is the currently used solution provided by Spring that leads to the problems). There would be another major advantage to this solution: dbojb 1.0.3 provides JdbcMetadataUtils.fillJCDFromDataSource which can be used to obtain initial information for the JDBC connection descriptor from the JDBC data source. Among this information is the value of "platform". I.e. we could get rid of the necessity to provide this information by patching it in the maven scripts (ending up with a WAR that can be deployed with a single RDBMS type only). The Jetspeed web application would then automatically adapt to the RDBMs used (as does JetspeedSecurityService already)!

      As has been discussed on the developer's list I'm going to provide the patches for the proposed change.

      Attachments

        1. j2-LocalDS-patches-20050811.txt.gz
          7 kB
          Michael Lipp
        2. j2-LocalDS-patches-20050817.txt.gz
          9 kB
          Michael Lipp
        3. j2-LocalDS-patches-20050820.txt
          9 kB
          Ate Douma
        4. j2-JNDI-lookup-20050910.txt
          6 kB
          Michael Lipp

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            ate Ate Douma
            drmlipp Michael Lipp
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              Updated:
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