Configure the CData JDBC Driver for Lakebase in a Connection Pool in Tomcat

The CData JDBC Drivers support standard JDBC interfaces to integrate with Web applications running on the JVM. This article details how to connect to Lakebase data from a connection pool in Tomcat.

Connect to Lakebase Data through a Connection Pool in Tomcat

1. Copy the CData JAR and CData .lic file to $CATALINA_HOME/lib. The CData JAR is located in the lib subfolder of the installation directory.
2. Add a definition of the resource to the context. Specify the JDBC URL here. To connect to Databricks Lakebase, start by setting the following properties:
   • DatabricksInstance: The Databricks instance or server hostname, provided in the format instance-abcdef12-3456-7890-abcd-abcdef123456.database.cloud.databricks.com.
   • Server: The host name or IP address of the server hosting the Lakebase database.
   • Port (optional): The port of the server hosting the Lakebase database, set to 5432 by default.
   • Database (optional): The database to connect to after authenticating to the Lakebase Server, set to the authenticating user's default database by default.

   OAuth Client Authentication

   To authenicate using OAuth client credentials, you need to configure an OAuth client in your service principal. In short, you need to do the following:

   1. Create and configure a new service principal
   2. Assign permissions to the service principal
   3. Create an OAuth secret for the service principal

   For more information, refer to the Setting Up OAuthClient Authentication section in the Help documentation.

   OAuth PKCE Authentication

   To authenticate using the OAuth code type with PKCE (Proof Key for Code Exchange), set the following properties:

   • AuthScheme: OAuthPKCE.
   • User: The authenticating user's user ID.

   For more information, refer to the Help documentation.

   Built-in Connection String Designer

   For assistance in constructing the JDBC URL, use the connection string designer built into the Lakebase JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

   java -jar cdata.jdbc.lakebase.jar
   

   Fill in the connection properties and copy the connection string to the clipboard.

   

   You can see the JDBC URL specified in the resource definition below.

   
   <Resource name="jdbc/lakebase"   auth="Container" type="javax.sql.DataSource" driverClassName="cdata.jdbc.lakebase.LakebaseDriver" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" url="jdbc:lakebase:DatabricksInstance=lakebase;Server=127.0.0.1;Port=5432;Database=my_database;InitiateOAuth=GETANDREFRESH;" maxActive="20" maxIdle="10" maxWait="-1" />
   

   To allow a single application to access Lakebase data, add the code above to the context.xml in the application's META-INF directory.

   For a shared resource configuration, add the code above to the context.xml located in $CATALINA_BASE/conf. A shared resource configuration provides connectivity to Lakebase for all applications.

3. Add a reference to the resource to the web.xml for the application.

   
     Lakebase data JSP
     jdbc/Lakebase
     javax.sql.DataSource
     Container
   
   

4. Initialize connections from the connection pool:

   Context initContext = new InitialContext();
   Context envContext  = (Context)initContext.lookup("java:/comp/env");
   DataSource ds = (DataSource)envContext.lookup("jdbc/Lakebase");
   Connection conn = ds.getConnection();
     

More Tomcat Integration

The steps above show how to connect to Lakebase data in a simple connection pooling scenario. For more use cases and information, see the JNDI Datasource How-To in the Tomcat documentation.