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

Create a DAO for the Postmark Bounces 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 MyBouncesDAO {
  //request specific data from Postmark (String type is used for simplicity)
  @SqlQuery("SELECT  FROM Bounces WHERE  = :")
  String findBy(@Bind("") String );

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

Open a Connection to Postmark

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

Using API Key Authentication

Postmark uses server API tokens to authenticate requests. Each Postmark server has its own API token, which controls access to messages, bounces, templates, and statistics associated with that server.

To obtain your Server API Token, log in to your Postmark account and navigate to the server you want to connect to. Go to API Tokens under the server settings and copy the token labeled Server API token.

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

• AuthScheme: Set this to APIKey.
• APIKey: Set this to your Postmark Server API Token. This value is sent as the X-Postmark-Server-Token header on every request.

Example connection string:

Profile=C:\profiles\Postmark.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your-server-api-token"

Connecting to Postmark

Once the authentication is configured, you can connect to Postmark and query data from any of the available tables such as OutboundMessages, Bounces, and Templates.

Built-in Connection String Designer

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

jdbc:api:Profile=C:\profiles\Postmark.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your-server-api-token"

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\Postmark.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your-server-api-token"");
MyBouncesDAO dao = dbi.open(MyBouncesDAO.class);

//do stuff with the DAO

dao.close();

Read Postmark Data

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

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

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