Integrating Derby with Spring Data JPA

September 21, 2025

This guide shows how to integrate Apache Derby with Spring Data JPA to manage data easily using repositories and minimal boilerplate code.

1. Add Dependencies

In pom.xml:

<dependency> <groupId>org.apache.derby</groupId> <artifactId>derby</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency>

2. Configure Derby

In application.properties:

spring.datasource.url=jdbc:derby:memory:demoDB;create=true spring.datasource.driver-class-name=org.apache.derby.jdbc.EmbeddedDriver spring.jpa.hibernate.ddl-auto=update

This sets up an in-memory Derby database that initializes on startup.

3. Create Entity

import jakarta.persistence.*; @Entity public class Employee { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; private String name; private String role; // getters and setters }

4. Create Repository

import org.springframework.data.jpa.repository.JpaRepository; public interface EmployeeRepository extends JpaRepository<Employee, Long> { }

Spring Data JPA automatically provides CRUD methods like save, findAll, findById, and deleteById.

5. Service Layer (Optional)

import org.springframework.stereotype.Service; import java.util.List; @Service public class EmployeeService { private final EmployeeRepository repo; public EmployeeService(EmployeeRepository repo) { this.repo = repo; } public List<Employee> getAll() { return repo.findAll(); } public Employee save(Employee e) { return repo.save(e); } }

6. REST Controller

import org.springframework.web.bind.annotation.*; import java.util.List; @RestController @RequestMapping("/employees") public class EmployeeController { private final EmployeeService service; public EmployeeController(EmployeeService service) { this.service = service; } @GetMapping public List<Employee> all() { return service.getAll(); } @PostMapping public Employee add(@RequestBody Employee e) { return service.save(e); } }

7. Test the API

Run Spring Boot:

mvn spring-boot:run

Test endpoints:

# Add employee curl -X POST http://localhost:8080/employees -H "Content-Type: application/json" -d '{"name":"Alice","role":"Developer"}' # Get all employees curl http://localhost:8080/employees