Introduction to Spring Data JPA

Use packages exercise1 and exercise2 when implementing the exercises.

The solutions can be found in the corresponding solution packages. For example the solution for exercise1 can be found in the package solution1.

Exercise 1

In this exercise you will implement a JPA repository for a simple blog application with the help of Spring Data JPA.

The application contains a simple model class blog.model.BlogPost. The application also defines a business interface blog.services.BlogService. At the moment the interface contains methods related only to the data access logic, but in the future it could be expanded to contain other logic as well.

Create a repository interface using Spring Data JPA and use that interface to implement the blog.services.BlogService interface. Please remember that Spring Data JPA provides most of the methods in its interfaces such as CrudRepository. You will only need to add finder methods with custom parameters.

Use autowiring to have Spring inject the repository implementation to your service class.

Before you can test the application, complete the Spring Data JPA configuration in exercise1/applicationContext.xml which you can find under src/main/resources. The XML namespace has already been defined as data-jpa.

Test the application by running the main application class exercise1.BlogConsole.

Exercise 2

In this second exercise you should use JPA Criteria API with Spring Data JPA instead of defining query methods in the DAO interface directly.

Remove queries from the repository interface. Rewrite the BlogService implementation to use the Specification interface instead.

Test the application by running the main application class exercise2.BlogConsole.