Create a Data Access Object for Azure Data Catalog Data using JDBI

JDBI is a SQL convenience library for Java that exposes two different style APIs, a fluent style and a SQL object style. The CData JDBC Driver for Azure Data Catalog integrates connectivity to live Azure Data Catalog data in Java applications. By pairing these technologies, you gain simple, programmatic access to Azure Data Catalog data. This article explains how to build a basic Data Access Object (DAO) and the accompanying code to read Azure Data Catalog data.

Create a DAO for the Azure Data Catalog Tables Entity

The interface below declares the desired behavior for the SQL object to create a single method for each SQL statement to be implemented.

public interface MyTablesDAO {
 //request specific data from Azure Data Catalog (String type is used for simplicity)
 @SqlQuery("SELECT Type FROM Tables WHERE Name = :name")
 String findTypeByName(@Bind("name") String name);

 /*
 * close with no args is used to close the connection
 */
 void close();
}

Open a Connection to Azure Data Catalog

Collect the necessary connection properties and construct the appropriate JDBC URL for connecting to Azure Data Catalog.

You can optionally set the following to read the different catalog data returned from Azure Data Catalog.

<>CatalogName: Set this to the CatalogName associated with your Azure Data Catalog. To get your Catalog name, navigate to your Azure Portal home page > Data Catalog > Catalog Name

Connect Using OAuth Authentication

You must use OAuth to authenticate with Azure Data Catalog. OAuth requires the authenticating user to interact with Azure Data Catalog using the browser. For more information, refer to the OAuth section in the help documentation.

Built-in Connection String Designer

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

java -jar cdata.jdbc.azuredatacatalog.jar

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

A connection string for Azure Data Catalog will typically look like the following:

jdbc:azuredatacatalog:InitiateOAuth=GETANDREFRESH;

Use the configured JDBC URL to obtain an instance of the DAO interface. The particular method shown below will open a handle bound to the instance, so the instance needs to be closed explicitly to release the handle and the bound JDBC connection.

DBI dbi = new DBI("jdbc:azuredatacatalog:InitiateOAuth=GETANDREFRESH;");
MyTablesDAO dao = dbi.open(MyTablesDAO.class);

//do stuff with the DAO

dao.close();

Read Azure Data Catalog Data

With the connection open to Azure Data Catalog, simply call the previously defined method to retrieve data from the Tables entity in Azure Data Catalog.

//disply the result of our 'find' method
String type = dao.findTypeByName("FactProductInventory");
System.out.println(type);

Since the JDBI library is able to work with JDBC connections, you can easily produce a SQL Object API for Azure Data Catalog by integrating with the CData JDBC Driver for Azure Data Catalog. Download a free trial and work with live Azure Data Catalog data in custom Java applications today.