Establishing a Connection
Creating a JDBC Data Source
You can create a JDBC data source to connect from your Java application. Creating a JDBC data source based on the CData JDBC Driver for WordPress consists of three basic steps:
- Add the driver JAR file to the classpath. The JAR file is located in the lib subfolder of the installation directory. Note that the .lic file must be located in the same folder as the JAR file.
- Provide the driver class. For example:
cdata.jdbc.wordpress.WordpressDriver
- Provide the JDBC URL. For example:
jdbc:wordpress:URL=http://www.yourwordpresshost.com;User=yourUsername;Password=yourPassword; or jdbc:cdata:wordpress:URL=http://www.yourwordpresshost.com;User=yourUsername;Password=yourPassword;
The second format above can be used whenever there is a conflict in your application between drivers using the same URL format to ensure you are using the CData driver. The URL must start with either "jdbc:wordpress:" or "jdbc:cdata:wordpress:" and can include any of the connection properties in name-value pairs separated with semicolons.
Connecting to WordPress
At this time, CData JDBC Driver for WordPress only supports connecting to self-hosted WordPress instances. To connect to data, supply the Url to your wordpress site, and then authenticate as described below.Supply the URL in its full form. For example, if your site is hosted at http://localhost/wp/wordpress', the URL should be http://localhost/wp/wordpress, and not 'htpp://localhost'. Failure to supply the URL in its full form results in a 'site not found' error.
WordPress supports two types of authentication:
- Basic authentication, which is recommended for use in a testing environment; and
- OAuth 2.0 authentication, which supports browser-based access from a Desktop application, Web application, or Headless Machine.
Basic Authentication
Basic authentication is recommended for testing environments only.Before you configure WordPress to use Basic Authentication:
- Ensure that your WordPress login has adminstrative privileges.
- Know what version of WordPress is running at the local host. (WordPress 4.7 and later support the WordPress REST API natively; earlier versions require the use of a Basic Authentication plug-in to secure access to the REST API.)
To configure Basic Authentication:
- Log into your WordPress host.
- If you are running an earlier WordPress version than 4.7, install the REST API plugin.
- Install the Basic Authentication plugin.
- To create custom taxonomies, install the Simple Taxonomy Refreshed
If you prefer installing the plugins manually, extract the compressed folders to the wp-content\plugins folder and then enable the plugins via the WordPress admin interface. - Set the following connection properties:
- AuthScheme: Basic.
- Url: Your WordPress URL.
- User: Your username.
- Password: Your password.
You are now ready to connect.
OAuth 2.0 Authentication
For all non-testing environments, WordPress supports OAuth authentication only. To enable this authentication from all OAuth flows, you must set AuthScheme to OAuth, and you must create a custom OAuth application.The following subsections describe how to authenticate to WordPress from three common authentication flows. For information about how to create a custom OAuth application, see Creating a Custom OAuth Application. For a complete list of connection string properties available in WordPress, see Connection.
Desktop Applications
To authenticate with the credentials for a custom OAuth application, you must get and refresh the OAuth access token. After you do that, you are ready to connect.Get and refresh the OAuth access token:
- InitiateOAuth: GETANDREFRESH. Used to automatically get and refresh the OAuthAccessToken.
- OAuthClientId: The client Id assigned when you registered your application.
- OAuthClientSecret: The client secret that was assigned when you registered your application.
- CallbackURL: The redirect URI that was defined when you registered your application.
When you connect, the driver opens WordPress's OAuth endpoint in your default browser. Log in and grant permissions to the application.
After you grant permissions to the application, the driver then completes the OAuth process:
- The driver obtains an access token from WordPress and uses it to request data.
- The OAuth values are saved in the path specified in OAuthSettingsLocation. These values persist across connections.
When the access token expires, the driver refreshes it automatically.
Web Applications
Authenticating via the Web requires you to create and register a custom OAuth application with WordPress, as described in Creating a Custom OAuth Application. You can then use the driver to get and manage the OAuth token values.This section describes how to get the OAuth access token, and how to have the driver refresh the OAuth access token automatically.
Get the OAuth access token:
- Set the following connection properties to obtain the OAuthAccessToken:
- OAuthClientId: The client Id in your application settings.
- OAuthClientSecret: The client secret in your application settings.
- Call stored procedures to complete the OAuth exchange:
- Call the GetOAuthAuthorizationURL stored procedure. Set the AuthMode input to WEB and the CallbackURL to the Redirect URI you specified in your application settings. The stored procedure returns the URL to the OAuth endpoint.
- Navigate to the URL that the stored procedure returned in Step 1. Log in and authorize the web application. You are redirected back to the callback URL.
- Call the GetOAuthAccessToken stored procedure. Set the AuthMode input to WEB. Set the Verifier input to the code parameter in the query string of the redirect URI.
After you obtain the access and refresh tokens, you can connect to data and refresh the OAuth access token automatically.
Automatic refresh of the OAuth access token:
To have the driver automatically refresh the OAuth access token, do the following:
- Before connecting to data for the first time, set the following connection parameters:
- InitiateOAuth: REFRESH.
- OAuthClientId: The client Id in your application settings.
- OAuthClientSecret: The client secret in your application settings.
- OAuthAccessToken: The access token returned by GetOAuthAccessToken.
- OAuthSettingsLocation: The path where you want the driver to save the OAuth values, which persist across connections.
- On subsequent data connections, set the following:
- InitiateOAuth
- OAuthSettingsLocation
Headless Machines
If you need to log in to a resource that resides on a headless machine, you must authenticate on another device that has an internet browser. You can do this in either of the following ways:
- Option 1: Obtain the OAuthVerifier value.
- Option 2: Install the driver on a machine with an internet browser and transfer the OAuth authentication values after you authenticate through the usual browser-based flow.
After you execute either Option 1 or Option 2, configure the driver to automatically refresh the access token on the headless machine.
Option 1: Obtaining and Exchanging a Verifier Code
To obtain a verifier code, you must authenticate at the OAuth authorization URL. Do the following:
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Authenticate from the machine with an internet browser, and obtain the OAuthVerifier connection property.
Set the following properties:
- InitiateOAuth: OFF.
- OAuthClientId: The client Id assigned when you registered your application.
- OAuthClientSecret: The client secret assigned when you registered your application.
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Call the GetOAuthAuthorizationURL stored procedure. The stored procedure returns the CallbackURL established when the custom OAuth application was registered. (See Creating a Custom OAuth Application.)
Copy this URL and paste it into a new browser tab.
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Log in and grant permissions to the driver. The OAuth application redirects you the redirect URI, with a parameter called code appended. Note the value of this parameter; you will need it later, to configure the OAuthVerifier connection property.
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Exchange the OAuth verifier code for OAuth refresh and access tokens. On the headless machine, set the following connection properties to obtain the OAuth authentication values:
- InitiateOAuth: REFRESH.
- OAuthVerifier: The noted verifier code (the value of the code parameter in the redirect URI).
- OAuthSettingsLocation: Persist the encrypted OAuth authentication values to the specified file.
- OAuthClientId: The client Id in your custom OAuth application settings.
- OAuthClientSecret: The client secret in the custom OAuth application settings.
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Test the connection to generate the OAuth settings file.
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After you re-set the following properties, you are ready to connect:
- InitiateOAuth: REFRESH.
- OAuthSettingsLocation: The file containing the encrypted OAuth authentication values. To enable the automatic refreshing of the access token, be sure that this file gives read and write permissions to the driver.
- OAuthClientId: The client Id assigned when you registered your application.
- OAuthClientSecret: The client secret assigned when you registered your application.
Option 2: Transferring OAuth Settings
Prior to connecting on a headless machine, you must install and create a connection with the driver on a device that supports an internet browser. Set the connection properties as described above in "Desktop Applications".
After completing the instructions in "Desktop Applications", the resulting authentication values are encrypted and written to the path specified by OAuthSettingsLocation. The default filename is OAuthSettings.txt.
Test the connection to generate the OAuth settings file, then copy the OAuth settings file to your headless machine.
To connect to data via the headless machine, set the following connection properties:
- InitiateOAuth: REFRESH
- OAuthSettingsLocation: The path to the OAuth settings file you copied from the machine with the browser. To enable automatic refreshing of the access token, ensure that this file gives read and write permissions to the driver.
- OAuthClientId: The client Id assigned when you registered your custom OAuth application.
- OAuthClientSecret: The client secret assigned when you registered your custom OAuth application.