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

Connect to AlloyDB 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.

   The following connection properties are usually required in order to connect to AlloyDB.

   • Server: The host name or IP of the server hosting the AlloyDB database.
   • User: The user which will be used to authenticate with the AlloyDB server.
   • Password: The password which will be used to authenticate with the AlloyDB server.

   You can also optionally set the following:

   • Database: The database to connect to when connecting to the AlloyDB Server. If this is not set, the user's default database will be used.
   • Port: The port of the server hosting the AlloyDB database. This property is set to 5432 by default.

   Authenticating with Standard Authentication

   Standard authentication (using the user/password combination supplied earlier) is the default form of authentication.

   No further action is required to leverage Standard Authentication to connect.

   Authenticating with pg_hba.conf Auth Schemes

   There are additional methods of authentication available which must be enabled in the pg_hba.conf file on the AlloyDB server.

   Find instructions about authentication setup on the AlloyDB Server here.

   Authenticating with MD5 Authentication

   This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to md5.

   Authenticating with SASL Authentication

   This authentication method must be enabled by setting the auth-method in the pg_hba.conf file to scram-sha-256.

   Authenticating with Kerberos

   The authentication with Kerberos is initiated by AlloyDB Server when the ∏ is trying to connect to it. You should set up Kerberos on the AlloyDB Server to activate this authentication method. Once you have Kerberos authentication set up on the AlloyDB Server, see the Kerberos section of the help documentation for details on how to authenticate with Kerberos.

   Built-in Connection String Designer

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

   java -jar cdata.jdbc.alloydb.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/alloydb" auth="Container" type="javax.sql.DataSource" driverClassName="cdata.jdbc.alloydb.AlloyDBDriver" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" url="jdbc:alloydb:User=alloydb;Password=admin;Database=alloydb;Server=127.0.0.1;Port=5432" maxActive="20" maxIdle="10" maxWait="-1" />
   

   To allow a single application to access AlloyDB 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 AlloyDB for all applications.

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

    AlloyDB data JSP
    jdbc/AlloyDB
    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/AlloyDB");
   Connection conn = ds.getConnection();
    

More Tomcat Integration

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