firstcrud

Simple Spring Boot application to manage students (CRUD) using Spring Data JPA.

Description

Demo project that exposes a REST API to create, read, update and delete Student entities.

Requirements

• Java 17
• Maven (the wrapper mvnw / mvnw.cmd is included)
• MySQL running (or change the configuration to another database)

Configuration

Default configuration is in src/main/resources/application.properties:

spring.datasource.url=jdbc:mysql://localhost:3306/first_crud spring.datasource.username=root spring.datasource.password=

Create the first_crud database in your MySQL server or adjust the URL/credentials to match your environment. The application uses spring.jpa.hibernate.ddl-auto=create-drop (it creates tables on startup and drops them on shutdown). Change this for production.

Relevant structure

• com.example.firstcrud.entity.Student — JPA entity with fields:

  • studentId (Long, @Id, auto-generated)
  • firstName (String)
  • lastname (String)
  • email (String) — column email_address, unique and not null

• com.example.firstcrud.controller.StudentController — REST endpoints under api/v1/students:

  • GET /api/v1/students — get all students
  • GET /api/v1/students/{studentId} — get a student by id
  • POST /api/v1/students — create or update a student (send JSON with entity fields)
  • DELETE /api/v1/students/{studentId} — delete by id

• com.example.firstcrud.service.StudentService — simple logic delegating to StudentRepository (Spring Data JPA)

• com.example.firstcrud.repository.StudentRepository — extends JpaRepository<Student, Long>

Build and run

In Windows PowerShell (from the project root C:\MyDevs\firstcrud):

1. Build and package:

.\mvnw.cmd clean package -DskipTests

2. Run the generated JAR:

java -jar target\firstcrud-0.0.1-SNAPSHOT.jar

Alternatively run in development mode with the wrapper:

.\mvnw.cmd spring-boot:run

Run tests

.\mvnw.cmd test

API usage examples

Using curl (examples):

• Get all students:

curl -X GET http://localhost:8080/api/v1/students

• Get a student by id (e.g. id=1):

curl -X GET http://localhost:8080/api/v1/students/1

• Create or update a student (POST) — example JSON:

curl -X POST http://localhost:8080/api/v1/students \
  -H "Content-Type: application/json" \
  -d '{"firstName":"Juan","lastname":"Pérez","email":"juan.perez@example.com"}'

If you prefer PowerShell you can use Invoke-RestMethod:

Invoke-RestMethod -Method Post -Uri http://localhost:8080/api/v1/students -ContentType 'application/json' -Body '{"firstName":"Juan","lastname":"Pérez","email":"juan.perez@example.com"}'

Notes and considerations

• Lombok is included to generate getters/setters automatically; if your IDE flags the annotations, install the Lombok plugin or enable annotation processing.
• The property spring.jpa.hibernate.ddl-auto=create-drop will delete data when the app stops. To persist data change it to update or manage schema migrations with Flyway/Liquibase.
• Update database credentials and URL in application.properties before running.
• Default port: 8080 (you can change it with server.port in application.properties).

Contributing

This project is a simple example. If you want to improve validation, error handling, add DTOs, tests or authentication, create a fork/branch and open a PR.

Contact

If you need help running the project, share the error you get and your database configuration.