Rest Repositories & HAL Explorer

https://github.com/spring-boot-tutorials/spring-data-rest-repositories-hal-explorer

In this article we will configure Rest Repositories in Spring Boot.

Create Initial Code Base

Go to https://start.spring.io/
Add the following dependencies: - rest repositories - lombok - jpa - h2
Click Generate

Dependencies

Dependencies used in pom.xml

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.8</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <scope>runtime</scope>
</dependency>

Properties

Add the following properties to src/main/resources/application.properties:

spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=

spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=none

# enables H2 console http://localhost:8080/h2-console
spring.h2.console.enabled=true

data.sql

Add the following into src/main/resources/data.sql:

-- Spring Boot will automatically pick up the data.sql and run
-- it against our configured H2 database during application startup.
-- This is a good way to seed the database for testing or other purposes

DROP TABLE IF EXISTS billionaire;
CREATE TABLE billionaire (
  id INT AUTO_INCREMENT PRIMARY KEY,
  first_name VARCHAR(250) NOT NULL,
  last_name VARCHAR(250) NOT NULL,
  career VARCHAR(250) DEFAULT NULL
);

INSERT INTO billionaire (first_name, last_name, career) VALUES
  ('Aliko', 'Dangote', 'Billionaire Industrialist'),
  ('Bill', 'Gates', 'Billionaire Tech Entrepreneur'),
  ('Folrunsho', 'Alakija', 'Billionaire Oil Magnate');

Model

Let’s create a new POJO src/main/java/com/example/Billionaire.java

@Entity
@Data
@SuperBuilder
@NoArgsConstructor
public class Billionaire {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NonNull
    private String firstName;

    @NonNull
    private String lastName;

    @NonNull
    private String career;
}

Repository

Next we will create a Spring repository to CRUD against the database.

This file will be called src/main/java/com/example/BillionaireRepository.java

@Repository
public interface BillionaireRepository extends PagingAndSortingRepository<Billionaire, Long> {

    @RestResource(rel = "first-name-contains", path="first-name-contains")
    Page<Billionaire> findByFirstNameContaining(@Param("query") String query, Pageable page);

    @RestResource(rel = "last-name-contains", path="last-name-contains", exported = false)
    Page<Billionaire> findByLastNameContaining(@Param("query") String query, Pageable page);
}

Run Application

Open terminal at project root and execute the following:

mvn spring-boot:run