Step 4: Configuring the Torque Runtime

Before we can start to write a Torque application, we have to configure the runtime environment:

• We have to make sure that the generated object model classes have access to the Torque runtime and associated libraries.
• The Torque runtime needs a configuration file in order to retrieve the data which is necessary to connect to the database.

Setting up the classpath

The libraries which the generated classes depend on are specified in the file project.xml in the top level directory of the project. You already created this file in step 3 of the tutorial; now it needs to be extended a bit. Assuming that you use JDK 1.4+, you need to add the following entries to the <dependencies> section of your project.xml

    <dependency>
      <artifactId>torque</artifactId>
      <groupId>torque</groupId>
      <version>3.3</version>
    </dependency>

    <dependency>
      <groupId>avalon-framework</groupId>
      <artifactId>avalon-framework-api</artifactId>
      <version>4.3</version>
      <url>http://avalon.apache.org/</url>
    </dependency>

    <dependency>
        <groupId>avalon-logkit</groupId>
        <artifactId>avalon-logkit</artifactId>
        <version>2.1</version>
        <type>jar</type>
    </dependency>

    <dependency>
      <groupId>commons-beanutils</groupId>
      <artifactId>commons-beanutils-core</artifactId>
      <version>1.7.0</version>
      <url>http://commons.apache.org/beanutils/</url>
    </dependency>

    <dependency>
      <groupId>commons-collections</groupId>
      <artifactId>commons-collections</artifactId>
      <version>3.2</version>
      <url>http://commons.apache.org/collections/</url>
    </dependency>

    <dependency>
      <groupId>commons-configuration</groupId>
      <artifactId>commons-configuration</artifactId>
      <version>1.4</version>
      <url>http://commons.apache.org/configuration/</url>
    </dependency>

    <dependency>
      <groupId>commons-dbcp</groupId>
      <artifactId>commons-dbcp</artifactId>
      <version>1.2.2</version>
      <url>http://commons.apache.org/dbcp/</url>
    </dependency>

    <dependency>
      <groupId>commons-lang</groupId>
      <artifactId>commons-lang</artifactId>
      <version>2.3</version>
      <url>http://commons.apache.org/lang/</url>
    </dependency>

    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.1</version>
      <url>http://commons.apache.org/logging/</url>
    </dependency>

    <dependency>
      <groupId>commons-pool</groupId>
      <artifactId>commons-pool</artifactId>
      <version>1.3</version>
      <url>http://commons.apache.org/pool/</url>
    </dependency>

    <dependency>
      <groupId>jcs</groupId>
      <artifactId>jcs</artifactId>
      <version>1.3</version>
      <url>http://jakarta.apache.org/jcs/</url>
    </dependency>

    <dependency>
      <artifactId>village</artifactId>
      <groupId>torque</groupId>
      <version>3.3</version>
    </dependency>

    <dependency>
      <groupId>xerces</groupId>
      <artifactId>xercesImpl</artifactId>
      <version>2.6.2</version>
      <url>http://xerces.apache.org/xerces2-j/</url>
    </dependency>

    <dependency>
      <groupId>xml-apis</groupId>
      <artifactId>xml-apis</artifactId>
      <version>2.0.2</version>
      <url>http://xml.apache.org/commons/</url>
    </dependency>

You don't need to download any of these libraries - Maven will download them automatically when you build your project.

Note: There is no need to include the torque-gen jar file in your project classpath, including it may adversly affect the logging configuration of your application.

Torque Runtime Properties

The second step in the configuration of the Torque Runtime are the Torque run-time properties. As the name suggests, these properties are used when your application is executing the object model code generated by Torque. The run-time properties control database parameters such as drivers, usernames, and passwords. These properties can be saved in any file because your application must explicitly initialize Torque (as you'll see later in this tutorial).

We will save our runtime properties in the a file called torque.properties. Create a subdirectory src/conf in the top-level directory of your project, and create a new file called torque.properties in it. Add the following lines to this file:

torque.database.default = bookstore
torque.database.bookstore.adapter = mysql

#Using commons-dbcp
torque.dsfactory.bookstore.factory = org.apache.torque.dsfactory.SharedPoolDataSourceFactory
torque.dsfactory.bookstore.connection.driver = org.gjt.mm.mysql.Driver
torque.dsfactory.bookstore.connection.url = jdbc:mysql://localhost:3306/bookstore
torque.dsfactory.bookstore.connection.user = user
torque.dsfactory.bookstore.connection.password = password
  

Change the adapter, driver, url, user and password parameters to match the parameters for your database. In the following table, the parameters used in the sample configuration are described. For further information, see the Runtime Configuration Reference.

It is worth re-iterating that these run-time properties are not used by Torque when generating your object model and creating your database. They are used only by the application utilizing the Torque-generated object model classes at run-time.

Logging configuration

Torque uses commons-logging as a logging interface. To enable logging in your application, read the commons-logging user guide.

If you have no trouble running the tutorial, you do not need to configure logging now. If, however, you experience runtime errors later on and do not find the reason immediately, it might be a good idea to configure logging and look at the log messages. Also, for a "serious" application, logging is indispensible in order to track down any unexpected errors.

Where to next

Now you have finished configuring the Torque runtime. You are now ready to use the generated classes to access the database.

Next we will look Writing a Sample Application.

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