Tranql and XAPool

Geronimo uses an interesting project to transform a jdbc driver into a resource adapter. This project is called Tranql. Its home page is http://tranql.codehaus.org/.

This page doesn't show a lot of informations and it is preferable to go to look at directly in the cvs ;-). The cvs is hosted by codehaus (cvs.tranql.codehaus.org) and the cvs root is /home/projects/tranql/scm.

The project only wrap JDBC driver and doesn't add support to convert a no-xa driver into an xa driver... An interested approach is to develop an integration between Tranql and XAPool. So you can easily create an XA DataSource from a simple DataSource and manage its connections with a JCA connection manager.

For example, with Tranql, you can configure a pool of connections with JCA in this way (using the Spring JCA support of Spring):

<bean id="tranqlManagedConnectionFactory"
      class="org.tranql.connector.jdbc.XADriverMCF">
  <property name="driverName">
    <value>org.hsqldb.jdbcDriver</value>
  </property>
  <property name="url">
    <value>jdbc:hsqldb:hsql://localhost:9002</value>
  </property>
  <property name="user">
    <value>sa</value>
  </property>
  <property name="password">
    <value></value>
  </property>
</bean>

So, to transform this DataSource in a XA compliant one, you only need to change the implementation of the ManagedConnectionManager. This XAPoolDataSourceMCF one integrates XAPool and use its StandardXADataSource class.
The configuration is now:

<bean id="tranqlManagedConnectionFactory"
      class="org.tranql.connector.jdbc.XAPoolDataSourceMCF ">
  <property name="driverName">
    <value>org.hsqldb.jdbcDriver</value>
  </property>
  <property name="url">
    <value>jdbc:hsqldb:hsql://localhost:9002</value>
  </property>
  <property name="user">
    <value>sa</value>
  </property>
  <property name="password">
    <value></value>
  </property>
</bean>

Note: A big problem is that XAPool internally manages the enlistment/delistment of XAResource. So you need to patch this tool to remove the call of enlist and delist on the current transaction.

Here is a sample implementation of XAPoolDataSourceMCF:

package org.tranql.connector.jdbc;

import java.sql.SQLException;

import javax.sql.XAConnection;
import javax.sql.XADataSource;

import org.enhydra.jdbc.standard.StandardXADataSource;
import org.tranql.connector.AllExceptionsAreFatalSorter;

public class XAPoolDataSourceMCF extends AbstractXADataSourceMCF {

  public XAPoolDataSourceMCF() {
    super(new StandardXADataSource(),new AllExceptionsAreFatalSorter());
  }

  public String getUserName() {
    return ((StandardXADataSource)xaDataSource).getUser();
  }

  public String getPassword() {
    return ((StandardXADataSource)xaDataSource).getPassword();
  }

  public void setDriverName(String driverName) {
    try {
      ((StandardXADataSource)xaDataSource).setDriverName(driverName);
    } catch (SQLException ex) { ex.printStackTrace(); }
  }

  public void setUrl(String url) {
    ((StandardXADataSource)xaDataSource).setUrl(url);
  }

  public void setUser(String user) {
    ((StandardXADataSource)xaDataSource).setUser(user);
  }

  public void setPassword(String password) {
    ((StandardXADataSource)xaDataSource).setPassword(password);
  }

}

The latest ManagedConnectionFactory implementation supports XA transactions!

Spring JCA support is out

The JCA CCI support is now integrated in the Spring framework 1.2.
You can view the corresponding org.springframework.jca package in the Spring CVS of at the following url:

http://cvs.sourceforge.net/viewcvs.py/springframework/spring/src/org/springframework/jca/