Configure the CData JDBC Driver for Cosmos DB 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 Cosmos DB data from a connection pool in Tomcat.

Connect to Cosmos DB 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 obtain the connection string needed to connect to a Cosmos DB account using the SQL API, log in to the Azure Portal, select Azure Cosmos DB, and select your account. In the Settings section, click Connection String and set the following values:

   • AccountEndpoint: The Cosmos DB account URL from the Keys blade of the Cosmos DB account
   • AccountKey: In the Azure portal, navigate to the Cosmos DB service and select your Azure Cosmos DB account. From the resource menu, go to the Keys page. Find the PRIMARY KEY value and set AccountKey to this value.

   Built-in Connection String Designer

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

   java -jar cdata.jdbc.cosmosdb.jar
   

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

   👁 Using the built-in connection string designer to generate a JDBC URL (Salesforce is shown.)
   

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

   <Resource name="jdbc/cosmosdb" auth="Container" type="javax.sql.DataSource" driverClassName="cdata.jdbc.cosmosdb.CosmosDBDriver" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" url="jdbc:cosmosdb:AccountEndpoint=myAccountEndpoint;AccountKey=myAccountKey;" maxActive="20" maxIdle="10" maxWait="-1" />
   

   To allow a single application to access Cosmos DB 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 Cosmos DB for all applications.

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

    Cosmos DB data JSP
    jdbc/CosmosDB
    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/CosmosDB");
   Connection conn = ds.getConnection();
    

More Tomcat Integration

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