Create a Data Access Object for Contentful 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 Contentful integrates connectivity to live Contentful data in Java applications. By pairing these technologies, you gain simple, programmatic access to Contentful data. This article explains how to build a basic Data Access Object (DAO) and the accompanying code to read Contentful data.

Create a DAO for the Contentful Assets 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 MyAssetsDAO {
  //request specific data from Contentful (String type is used for simplicity)
  @SqlQuery("SELECT SpaceId FROM Assets WHERE ContentType = :contentType")
  String findSpaceIdByContentType(@Bind("contentType") String contentType);

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

Open a Connection to Contentful

Collect the necessary connection properties and construct the appropriate JDBC URL for connecting to Contentful.

Start by setting the Profile connection property to the location of the Contentful Profile on disk (e.g. C:\profiles\Contentful.apip). Next, set the ProfileSettings connection property to the connection string for Contentful (see below).

Contentful API Profile Settings

Obtain your Content Delivery API access token from your Contentful space settings under Settings > API Keys. Your SpaceId is visible in your Contentful workspace configuration.

Built-in Connection String Designer

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

java -jar cdata.jdbc.api.jar

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

A connection string for Contentful will typically look like the following:

jdbc:api:Profile=C:\profiles\Contentful.apip;ProfileSettings='APIKey=your_access_token;SpaceId=your_space_id';

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:api:Profile=C:\profiles\Contentful.apip;ProfileSettings='APIKey=your_access_token;SpaceId=your_space_id';");
MyAssetsDAO dao = dbi.open(MyAssetsDAO.class);

//do stuff with the DAO

dao.close();

Read Contentful Data

With the connection open to Contentful, simply call the previously defined method to retrieve data from the Assets entity in Contentful.

//disply the result of our 'find' method
String spaceId = dao.findSpaceIdByContentType("image/jpeg");
System.out.println(spaceId);

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