To add Spring Data JPA and H2 to our already drafted app, we can easily use the same tactic from Chapter 2, Creating a Web Application with Spring Boot (using start.spring.io to build apps):
Visit start.spring.io.
Enter the same project artifact details as before.
Click on DEPENDENCIES.
Select Spring Data JPA and H2.
Click on EXPLORE.
Look for the pom.xml file and click on it.
Copy the new bits onto the clipboard.
Open up our previous project inside our IDE.
Open our pom.xml file and paste the new bits into the right places.