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

Create a DAO for the WordPress Categories 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 MyCategoriesDAO {
 //insert new data into WordPress
 @SqlUpdate("INSERT INTO Categories (Id, Name) values (:id, :name)")
 void insert(@Bind("id") String id, @Bind("name") String name);

 //request specific data from WordPress (String type is used for simplicity)
 @SqlQuery("SELECT Name FROM Categories WHERE Id = :id")
 String findNameById(@Bind("id") String id);

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

Open a Connection to WordPress

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

To connect to WordPress, set the URL property and other authentication properties. WordPress supports Basic (User and Password) and OAuth2.0 authentication, though Basic is recommended for a testing environment only. To connect with OAuth register an app with WordPress.

See the Getting Started guide in the CData driver documentation for more information.

Built-in Connection String Designer

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

java -jar cdata.jdbc.wordpress.jar

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

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

jdbc:wordpress:Url=http://www.yourwordpresshost.com;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:wordpress:Url=http://www.yourwordpresshost.com;InitiateOAuth=GETANDREFRESH;");
MyCategoriesDAO dao = dbi.open(MyCategoriesDAO.class);

//do stuff with the DAO

dao.close();

Read WordPress Data

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

//disply the result of our 'find' method
String name = dao.findNameById("1");
System.out.println(name);

Write WordPress Data

It is also simple to write data to WordPress, using the previously defined method.

//add a new entry to the Categories entity
dao.insert(newId, newName);

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