Connect to Azure Data Lake Storage Data from a Connection Pool in Jetty

The CData JDBC driver for Azure Data Lake Storage is easy to integrate with Java Web applications. This article shows how to efficiently connect to Azure Data Lake Storage data in Jetty by configuring the driver for connection pooling. You will configure a JNDI resource for Azure Data Lake Storage in Jetty.

Configure the JDBC Driver for Salesforce as a JNDI Data Source

Follow the steps below to connect to Salesforce from Jetty.

1. Enable the JNDI module for your Jetty base. The following command enables JNDI from the command-line:

   java -jar ../start.jar --add-to-startd=jndi
2. Add the CData and license file, located in the lib subfolder of the installation directory, into the lib subfolder of the context path.

3. Declare the resource and its scope. Enter the required connection properties in the resource declaration. This example declares the Azure Data Lake Storage data source at the level of the Web app, in WEB-INF\jetty-env.xml.

   <Configure id='azuredatalakedemo' class="org.eclipse.jetty.webapp.WebAppContext"> <New id="azuredatalakedemo" class="org.eclipse.jetty.plus.jndi.Resource"> <Arg><Ref refid="azuredatalakedemo"/></Arg> <Arg>jdbc/azuredatalakedb</Arg> <Arg> <New class="cdata.jdbc.adls.ADLSDriver"> <Set name="url">jdbc:adls:</Set> <Set name="Schema">ADLSGen2</Set> <Set name="Account">myAccount</Set> <Set name="FileSystem">myFileSystem</Set> <Set name="AccessKey">myAccessKey</Set> <Set name="InitiateOAuth">GETANDREFRESH</Set> </New> </Arg> </New> </Configure>

   Authenticating to a Gen 1 DataLakeStore Account

   Gen 1 uses OAuth 2.0 in Azure AD for authentication.

   For this, an Active Directory web application is required. You can create one as follows:

   1. Sign in to your Azure Account through the .
   2. Select "Azure Active Directory".
   3. Select "App registrations".
   4. Select "New application registration".
   5. Provide a name and URL for the application. Select Web app for the type of application you want to create.
   6. Select "Required permissions" and change the required permissions for this app. At a minimum, "Azure Data Lake" and "Windows Azure Service Management API" are required.
   7. Select "Key" and generate a new key. Add a description, a duration, and take note of the generated key. You won't be able to see it again.

   To authenticate against a Gen 1 DataLakeStore account, the following properties are required:

   • Schema: Set this to ADLSGen1.
   • Account: Set this to the name of the account.
   • OAuthClientId: Set this to the application Id of the app you created.
   • OAuthClientSecret: Set this to the key generated for the app you created.
   • TenantId: Set this to the tenant Id. See the property for more information on how to acquire this.
   • Directory: Set this to the path which will be used to store the replicated file. If not specified, the root directory will be used.

   Authenticating to a Gen 2 DataLakeStore Account

   To authenticate against a Gen 2 DataLakeStore account, the following properties are required:

   • Schema: Set this to ADLSGen2.
   • Account: Set this to the name of the account.
   • FileSystem: Set this to the file system which will be used for this account.
   • AccessKey: Set this to the access key which will be used to authenticate the calls to the API. See the property for more information on how to acquire this.
   • Directory: Set this to the path which will be used to store the replicated file. If not specified, the root directory will be used.

4. Configure the resource in the Web.xml:

   jdbc/azuredatalakedb javax.sql.DataSource Container

5. You can then access Azure Data Lake Storage with a lookup to java:comp/env/jdbc/azuredatalakedb: InitialContext ctx = new InitialContext(); DataSource myazuredatalake = (DataSource)ctx.lookup("java:comp/env/jdbc/azuredatalakedb");

More Jetty Integration

The steps above show how to configure the driver in a simple connection pooling scenario. For more use cases and information, see the Working with Jetty JNDI chapter in the Jetty documentation.