Derby (JPA) #WIP#

https://github.com/spring-boot-tutorials/spring-data-derby-jpa

In this article we will configure Spring Boot to connect to a Derby database.

Derby Server

Run Derby database without saving to local filesystem:

docker run \
  -p 1527:1527 \
  -e DBNAME=testdb \
  -e DERBY_USER=my_user \
  -e DERBY_PASSWORD=my_password \
  --name derby_instance \
  adito/derby

Run Derby database while saving to local filesystem:

docker run \
  -p 1527:1527 \
  -e DBNAME=testdb \
  -e DERBY_USER=my_user \
  -e DERBY_PASSWORD=my_password \
  -v $(pwd)/dbs:/dbs \
  --name derby_instance \
  adito/derby

Create Initial Code Base

• Go to https://start.spring.io/

• Click Add Dependencies, search for Derby, then add

• Click Add Dependencies, search for Lombok, then add

• 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.apache.derby</groupId>
    <artifactId>derbyclient</artifactId>
</dependency>
<dependency>
    <groupId>org.apache.derby</groupId>
    <artifactId>derby</artifactId>

<!– <scope>runtime</scope>–>

</dependency> <dependency>

<groupId>org.apache.derby</groupId> <artifactId>derbytools</artifactId>

<!– <scope>runtime</scope>–>

</dependency> <dependency>

<groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional>

</dependency>

Properties

In src/main/resources/application.properties let’s add the following properties so the Spring Boot application can connect to the Cassandra database

# Increased timeout to fit slower environments like TravisCI
spring.couchbase.env.timeouts.view=15000
spring.couchbase.env.timeouts.query=15000
spring.couchbase.connection-string=couchbase://127.0.0.1
spring.couchbase.username=admin
spring.couchbase.password=password
spring.data.couchbase.bucket-name=travel-sample
spring.data.couchbase.auto-index=true

Configuration

Let’s create a file src/main/java/com/example/Couchbase/config/CouchbaseConfiguration.java:

@Configuration
public class CouchbaseConfiguration {

    @Autowired
    CouchbaseTemplate couchbaseTemplate;

    @Autowired
    Cluster cluster;

    /**
     * Add the _class field to all Airline documents
     */
    @PostConstruct
    private void postConstruct() {
        cluster.queryIndexes().createPrimaryIndex(
                couchbaseTemplate.getBucketName(),
                CreatePrimaryQueryIndexOptions.createPrimaryQueryIndexOptions().ignoreIfExists(true)
        );

        // Need to post-process travel data to add _class attribute
        cluster.query("update `travel-sample` set _class='" + Airline.class.getName() + "' where type = 'airline'");
    }
}

Model

Let’s create a new POJO src/main/java/com/example/cassandra/model/Airline.java

@Data
@Document
@SuperBuilder
@NoArgsConstructor
@JsonIgnoreProperties(ignoreUnknown = true)
public class Airline {

    @Id
    private String id;
    private String name;
    private String iata;
    private String icao;
    private String callsign;
    private String country;
}

Repository

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

This file will be called src/main/java/com/example/Couchbase/repository/AirlineRepository.java

@Repository
public interface AirlineRepository extends CrudRepository<Airline, String> {

    List<Airline> findByIata(String code);
}

Main

Now let’s use this repository.

Go back to CassandraApplication.java and add the following:

...
@SpringBootApplication
public class CouchbaseApplication implements CommandLineRunner {

    public static void main(String[] args) {
            SpringApplication.run(CouchbaseApplication.class, args);
    }

    @Autowired
    AirlineRepository airlineRepository;

    @Override
    public void run(String... args) throws Exception {
            airlineRepository.deleteAll();

            // 1. save
            Airline airline = Instancio.create(Airline.class);
            airline.setIata("iata");
            airline = airlineRepository.save(airline);
            System.out.println("1. " + airline);

            // 2. saveAll
            int count = 10;
            var airlines = Instancio.ofList(Airline.class)
                            .size(count)
                            .create();
            System.out.println("2. saveAll");
            airlineRepository.saveAll(airlines)
                            .forEach(System.out::println);

            // 3. Query Methods
            System.out.println("3. query methods");
            airlineRepository.findByIata("iata").forEach(System.out::println);
    }
}

Run Application

Open terminal at project root and execute the following:

mvn spring-boot:run

There should be no errors and the output will display all the CRUD operations.