Object-Relational Mapping (ORM) with Outlook Data Entities in Java

Jerod Johnson
Jerod Johnson
Director, Technology Evangelism
Object-relational mapping (ORM) techniques make it easier to work with relational data sources and can bridge your logical business model with your physical storage model. Follow this tutorial to integrate connectivity to Outlook data into a Java-based ORM framework, Hibernate.

You can use Hibernate to map object-oriented domain models to a traditional relational database. The tutorial below shows how to use the CData JDBC Driver for Outlook to generate an ORM of your Outlook repository with Hibernate.

Though Eclipse is the IDE of choice for this article, the CData JDBC Driver for Outlook works in any product that supports the Java Runtime Environment. In the Knowledge Base you will find tutorials to connect to Outlook data from IntelliJ IDEA and NetBeans.

Install Hibernate

Follow the steps below to install the Hibernate plug-in in Eclipse.

  1. In Eclipse, navigate to Help -> Install New Software.
  2. Enter "http://download.jboss.org/jbosstools/neon/stable/updates/" in the Work With box.
  3. Enter "Hibernate" into the filter box.
  4. Select Hibernate Tools.

Start A New Project

Follow the steps below to add the driver JARs in a new project.

  1. Create a new project. Select Java Project as your project type and click Next. Enter a project name and click Finish.
  2. Right-click the project and click Properties. Click Java Build Path and then open the Libraries tab.
  3. Click Add External JARs to add the cdata.jdbc.api.jar library, located in the lib subfolder of the installation directory.

Add a Hibernate Configuration File

Follow the steps below to configure connection properties to Outlook data.

  1. Right-click on the new project and select New -> Hibernate -> Hibernate Configuration File (cfg.xml).
  2. Select src as the parent folder and click Next.
  3. Input the following values:

    • Hibernate version:: 5.2
    • Database dialect: Derby
    • Driver class: cdata.jdbc.api.APIDriver
    • Connection URL: A JDBC URL, starting with jdbc:api: and followed by a semicolon-separated list of connection properties.

      Using OAuth Authentication

      Microsoft Graph API uses OAuth 2.0 for authentication. You must register an application in the Microsoft Azure Portal to obtain OAuth credentials (Client ID and Client Secret).

      Obtaining OAuth Credentials

      1. Log in to the Azure Portal.
      2. Navigate to Azure Active Directory > App registrations.
      3. Click New registration to create a new application.
      4. Enter an application name and select the appropriate account types.
      5. Set the Redirect URI to your application's callback URL (e.g., http://localhost:33333 for desktop apps).
      6. Click Register to create the application.
      7. On the application overview page, copy the Application (client) ID - this is your OAuthClientId.
      8. Navigate to Certificates & secrets and create a new client secret.
      9. Copy the client secret value - this is your OAuthClientSecret.
      10. Navigate to API permissions and add the required Microsoft Graph API permissions:
        • Mail.Read - For accessing email messages
        • Contacts.Read - For accessing contacts
        • Calendars.Read - For accessing calendar events
        • Tasks.Read - For accessing To Do tasks
        • offline_access - For obtaining refresh tokens
      11. Click Grant admin consent to grant these permissions.

      Connecting with OAuth

      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 Outlook will automatically walk through the OAuth process in order to obtain the access token.
      • OAuthClientId: Set this to the Application (client) ID from Azure Portal.
      • OAuthClientSecret: Set this to the client secret value from Azure Portal.
      • TenantId: Set this to your Azure AD tenant identifier (GUID or domain name like 'contoso.onmicrosoft.com').
      • CallbackURL: Set this to the Redirect URI you specified in your app registration (e.g., http://localhost:33333 for desktop apps).

      Example connection string

      Profile=C:\profiles\Outlook.apip;AuthScheme=OAuth;InitiateOAuth=GETANDREFRESH;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;TenantId=your_tenant_id;CallbackUrl=http://localhost:33333;
      

      Built-in Connection String Designer

      For assistance in constructing the JDBC URL, use the connection string designer built into the Outlook 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 typical JDBC URL is below:

      jdbc:api:Profile=C:\profiles\Outlook.apip;AuthScheme=OAuth;InitiateOAuth=GETANDREFRESH;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;TenantId=your_tenant_id;CallbackUrl=http://localhost:33333;

Connect Hibernate to Outlook Data

Follow the steps below to select the configuration you created in the previous step.

  1. Switch to the Hibernate Configurations perspective: Window -> Open Perspective -> Hibernate.
  2. Right-click on the Hibernate Configurations panel and click Add Configuration.
  3. Set the Hibernate version to 5.2.
  4. Click the Browse button and select the project.
  5. For the Configuration file field, click Setup -> Use Existing and select the location of the hibernate.cfg.xml file (inside src folder in this demo).
  6. In the Classpath tab, if there is nothing under User Entries, click Add External JARS and add the driver jar once more. Click OK once the configuration is done.
  7. Expand the Database node of the newly created Hibernate configurations file.

Reverse Engineer Outlook Data

Follow the steps below to generate the reveng.xml configuration file. You will specify the tables you want to access as objects.

  1. Switch back to the Package Explorer.
  2. Right-click your project, select New -> Hibernate -> Hibernate Reverse Engineering File (reveng.xml). Click Next.
  3. Select src as the parent folder and click Next.
  4. In the Console configuration drop-down menu, select the Hibernate configuration file you created above and click Refresh.
  5. Expand the node and choose the tables you want to reverse engineer. Click Finish when you are done.

Configure Hibernate to Run

Follow the steps below to generate plain old Java objects (POJO) for the Outlook tables.

  1. From the menu bar, click Run -> Hibernate Code Generation -> Hibernate Code Generation Configurations.
  2. In the Console configuration drop-down menu, select the Hibernate configuration file you created in the previous section. Click Browse by Output directory and select src.
  3. Enable the Reverse Engineer from JDBC Connection checkbox. Click the Setup button, click Use Existing, and select the location of the hibernate.reveng.xml file (inside src folder in this demo).
  4. In the Exporters tab, check Domain code (.java) and Hibernate XML Mappings (hbm.xml).
  5. Click Run.

One or more POJOs are created based on the reverse-engineering setting in the previous step.

Insert Mapping Tags

For each mapping you have generated, you will need to create a mapping tag in hibernate.cfg.xml to point Hibernate to your mapping resource. Open hibernate.cfg.xml and insert the mapping tags as so:





  
    
      cdata.api.APIDriver
    
    
      jdbc:api:Profile=C:\profiles\Outlook.apip;AuthScheme=OAuth;InitiateOAuth=GETANDREFRESH;OAuthClientId=your_client_id;OAuthClientSecret=your_client_secret;TenantId=your_tenant_id;CallbackUrl=http://localhost:33333;
    
    
      org.hibernate.dialect.SQLServerDialect
    
    
     
    

Execute SQL

Using the entity you created from the last step, you can now search Outlook data:


import java.util.*;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
import org.hibernate.query.Query;

public class App {
  public static void main(final String[] args) {
    Session session =  new
    Configuration().configure().buildSessionFactory().openSession();
    String SELECT = "FROM CalendarGroupCalendars C WHERE CalendarGroupId = :CalendarGroupId";
    Query q = session.createQuery(SELECT, CalendarGroupCalendars.class);
    q.setParameter("CalendarGroupId","group_id");
    List<CalendarGroupCalendars> resultList = (List<CalendarGroupCalendars>) q.list();

    for(CalendarGroupCalendars s: resultList){
      System.out.println(s.get());
      System.out.println(s.get());
    }
  }
}

Ready to get started?

Connect to live data from Outlook with the API Driver

Connect to Outlook