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

Create a DAO for the Gumroad CustomFields 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 MyCustomFieldsDAO {
  //request specific data from Gumroad (String type is used for simplicity)
  @SqlQuery("SELECT  FROM CustomFields WHERE ProductId = :productId")
  String findByProductId(@Bind("productId") String productId);

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

Open a Connection to Gumroad

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

Using OAuth Authentication

To authenticate to Gumroad and connect to your own data or to allow other users to connect to their data, you can use the OAuth 2.0 standard. This is the recommended authentication method.

First you need to register an OAuth application with Gumroad. You can create an OAuth application by visiting your Gumroad account settings at https://app.gumroad.com/settings/advanced and navigating to the Applications section.

After setting the following connection properties, you are ready to connect:

• AuthScheme: Set this to OAuth.
• InitiateOAuth: Set this to GETANDREFRESH. The CData API Profile for Gumroad will automatically walk through the OAuth process in order to obtain the access token.
• OAuthClientID: Set this to the client_id that is specified in your app settings.
• OAuthClientSecret: Set this to the client_secret that is specified in your app settings.
• CallbackURL: Set this to the Redirect URI you specified in your app settings.

Example connection string

Profile=C:\profiles\Gumroad.apip;AuthScheme=OAuth;InitiateOAuth=GETANDREFRESH;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;CallbackUrl=your_callback_url;

Built-in Connection String Designer

For assistance in constructing the JDBC URL, use the connection string designer built into the Gumroad 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 Gumroad will typically look like the following:

jdbc:api:Profile=C:\profiles\Gumroad.apip;AuthScheme=OAuth;InitiateOAuth=GETANDREFRESH;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;CallbackUrl=your_callback_url;

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\Gumroad.apip;AuthScheme=OAuth;InitiateOAuth=GETANDREFRESH;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;CallbackUrl=your_callback_url;");
MyCustomFieldsDAO dao = dbi.open(MyCustomFieldsDAO.class);

//do stuff with the DAO

dao.close();

Read Gumroad Data

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

//disply the result of our 'find' method
String  = dao.findByProductId("prod_abc123xyz");
System.out.println();

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