Connecting Spring Boot with PostgreSQL: Complete Example

PostgreSQL is one of the most powerful and popular open-source relational databases available today. Whether you’re building a CRUD API, a SaaS platform, or a microservice, connecting Spring Boot to PostgreSQL is a common and essential skill for backend Java developers. If you’re looking for a practical Spring Boot PostgreSQL example, you’re in the right place.

In this guide, you’ll learn how to connect a Spring Boot 3 application to PostgreSQL, set up your configuration, define your models, and perform basic CRUD operations using Spring Data JPA — all using best practices in 2025.

🧱 Prerequisites

Java 17 or higher
Spring Boot 3.x
PostgreSQL installed and running locally or in the cloud (e.g., Docker, pgAdmin, or Supabase)
IDE (IntelliJ IDEA, VSCode, etc.)

⚙️ Step 1: Create a New Spring Boot Project

Use Spring Initializr with the following setup:

Dependencies:
- Spring Web
- Spring Data JPA
- PostgreSQL Driver
- Spring Boot DevTools

Then click “Generate” to download your project and open it in your IDE.

🧾 Step 2: Configure PostgreSQL in `application.properties`

spring.datasource.url=jdbc:postgresql://localhost:5432/demo_db
spring.datasource.username=postgres
spring.datasource.password=your_password

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect

🔐 Tip: For production apps, store credentials securely using environment variables or Spring Cloud Config.

📦 Step 3: Create an Entity

@Entity
public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;
    private Double price;

    // Getters and setters omitted for brevity
}

💾 Step 4: Create a Repository

public interface ProductRepository extends JpaRepository {
}

Spring Data JPA provides all the basic CRUD methods out-of-the-box — no need to implement them manually.

🎯 Step 5: Create a REST Controller

@RestController
@RequestMapping("/api/products")
public class ProductController {

    @Autowired
    private ProductRepository productRepository;

    @GetMapping
    public List getAll() {
        return productRepository.findAll();
    }

    @PostMapping
    public Product create(@RequestBody Product product) {
        return productRepository.save(product);
    }

    @GetMapping("/{id}")
    public Product getById(@PathVariable Long id) {
        return productRepository.findById(id)
                .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
    }

    @DeleteMapping("/{id}")
    public void delete(@PathVariable Long id) {
        productRepository.deleteById(id);
    }
}

✅ You now have a fully functional CRUD API connected to PostgreSQL.

🧪 Test It with Postman

POST /api/products

{
  "name": "MacBook Air M3",
  "price": 1299.99
}

GET /api/products
Returns all products
GET /api/products/{id}
Returns a single product
DELETE /api/products/{id}
Deletes a product

🐘 PostgreSQL Setup Tips

Use tools like pgAdmin, TablePlus, or DBeaver for easy DB management
Use Docker for consistent local development:

docker run --name pgdb -e POSTGRES_PASSWORD=your_password -p 5432:5432 -d postgres

Use schemas and constraints (@Column(nullable = false) or @UniqueConstraint) for production-grade models

How to Handle Exceptions Globally in Spring Boot

🧠 Final Thoughts

Spring Boot and PostgreSQL work seamlessly together — especially when paired with Spring Data JPA, which removes the boilerplate of database interaction. This setup is perfect for REST APIs, internal tools, and full-stack apps needing robust relational data.

Now that you’re connected, you can explore:

✅ Adding validation with @Valid and @Validated
✅ Advanced querying with @Query or Specification API
✅ Security with Spring Security + JWT
✅ Containerizing your app with Docker

🧱 Prerequisites

⚙️ Step 1: Create a New Spring Boot Project

🧾 Step 2: Configure PostgreSQL in application.properties