How to use BTM as the transaction manager in Tomcat 5.5.x

These instructions have been verified against BTM 1.1.

Contents

Step 1: Copy the BTM jars

Copy the following jars from the BTM distribution to the Tomcat common/lib/ directory:

• btm-1.1.jar
• geronimo-spec-jta-1.0.1B-rc4.jar
• slf4j-jdk14.jar (or any other one available here)

Step 2: Configure BTM as the transaction manager

Windows: Create a file named setenv.bat with the following commands under Tomcat's bin/ directory:

set CATALINA_OPTS=-Dbtm.root=%CATALINA_HOME% -Dbitronix.tm.configuration=%CATALINA_HOME%\conf\btm-config.properties

Unix: Create a file named setenv.sh with the following commands under Tomcat's bin/ directory:

CATALINA_OPTS="-Dbtm.root=$CATALINA_HOME -Dbitronix.tm.configuration=$CATALINA_HOME/conf/btm-config.properties"

Now create a file named btm-config.properties with the following properties under Tomcat's conf/ directory:

bitronix.tm.serverId=tomcat-btm-node0
bitronix.tm.journal.disk.logPart1Filename=${btm.root}/work/btm1.tlog
bitronix.tm.journal.disk.logPart2Filename=${btm.root}/work/btm2.tlog
bitronix.tm.resource.configuration=${btm.root}/conf/resources.properties

Finally, create an empty file named resources.properties under Tomcat's conf/ directory.

Step 3: Configure datasources that are transaction aware

You have to put your datasources configurations in Tomcat's conf/resources.properties file. Here's an example of using BTM with a DataSource that implements javax.sql.XADataSource:

resource.ds1.className=org.apache.derby.jdbc.EmbeddedXADataSource
resource.ds1.uniqueName=jdbc/mydatasource
resource.ds1.minPoolSize=0
resource.ds1.maxPoolSize=5
resource.ds1.driverProperties.databaseName=db1
resource.ds1.driverProperties.createDatabase=create

This will create a bitronix.tm.resource.jdbc.PoolingDataSource that implements javax.sql.DataSource and interacts with the javax.sql.XADataSource provided in this instance by Derby.

If your database vendor does not provide an XADataSource, you can use BTM's bitronix.tm.resource.jdbc.lrc.LrcXADataSource as the XADataSource to allow your database connections to be controlled by the transaction manager:

resource.ds2.className=bitronix.tm.resource.jdbc.lrc.LrcXADataSource
resource.ds2.uniqueName=jdbc/exampleNonXADS
resource.ds2.minPoolSize=0
resource.ds2.maxPoolSize=5
resource.ds2.driverProperties.driverClassName=org.apache.derby.jdbc.EmbeddedDriver
resource.ds2.driverProperties.url=jdbc:derby::db2;create=true

Again, we've used Derby as an example, but as the LrcXADataSource uses only the class name and url of a java.sql.Driver, you can use it with any database providing a JDBC driver.

Step 4: Configure transaction manager and datasources initialization in your META-INF/context.xml

In the web application where you want one or more datasource to be used, you have to create a META-INF/context.xml file.

<Context>

    <Resource name="jdbc/mydatasource" auth="Container" type="javax.sql.DataSource"
        factory="bitronix.tm.resource.ResourceObjectFactory" uniqueName="jdbc/mydatasource" />

    <Resource name="jdbc/exampleNonXADS" auth="Container" type="javax.sql.DataSource"
        factory="bitronix.tm.resource.ResourceObjectFactory" uniqueName="jdbc/exampleNonXADS" />

    <Transaction factory="bitronix.tm.BitronixUserTransactionObjectFactory" />

</Context>

The <Resource> tags will bind a bitronix.tm.resource.ResourceObjectFactory object each, passing it a javax.naming.Reference containing a javax.naming.StringRefAddr containing the datasource's uniqueName as addrType.

The bitronix.tm.resource.ResourceObjectFactory class will return the datasource previously configured in in Tomcat's conf/resources.properties with the specified uniqueName when it is fetched from JNDI.

The <Transaction> tag will just bind the transaction manager at the standard JNDI location java:comp/UserTransaction.

Step 5: Configure datasources references in your web.xml

Before your code can access configured datasources via JNDI ENC URLs, you need to declare resource references in your web.xml:

<?xml version="1.0" encoding="ISO-8859-1"?>
 <!DOCTYPE web-app PUBLIC
	"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
	"http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>
  <resource-env-ref>
    <resource-env-ref-name>jdbc/mydatasource</resource-env-ref-name>
    <resource-env-ref-type>javax.sql.DataSource</resource-env-ref-type>
  </resource-env-ref>

  <resource-env-ref>
    <resource-env-ref-name>jdbc/exampleNonXADS</resource-env-ref-name>
    <resource-env-ref-type>javax.sql.DataSource</resource-env-ref-type>
  </resource-env-ref>
</web-app>

Now you can perform JNDI lookups on those URLs to access the configured datasources:

DataSource exampleNonXADS = ctx.lookup("java:comp/env/jdbc/exampleNonXADS");
DataSource mydatasource = ctx.lookup("java:comp/env/jdbc/mydatasource");