Initially, before implementing the domain model, the dependencies and configuration classes need to be specified. The following Maven starter dependency and H2 database dependency need to be included:

<dependencies>
    ...
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
 
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <version>1.4.196</version>
    </dependency>
</dependencies>

The following RepoConfig is used:

@Configuration
@EnableJpaRepositories(basePackages = "com.packtpub.spring.boot.email.formatter.model")
@EnableTransactionManagement
@EntityScan(basePackages = "com.packtpub.spring.boot.email.formatter.model.domain")
public class RepoConfig {
}

The @EnableJpaRepositories annotation is used to set the base package where repositories are available. @EnableTransactionManagement is used to enable the Spring JPA Transaction Manager. The @EntityScan annotation is used to set the base package where domain entities are available.