Creating a Spring Boot CRUD REST API with MySQL and Image Upload – Step-by-Step Guide

In today’s full-stack development, building a robust backend API is essential for powering dynamic web or mobile applications. In this tutorial, we’ll walk you through creating a Spring Boot CRUD REST API using MySQL as the database and also handling image upload. Whether you’re building a user management system or an admin dashboard, CRUD operations (Create, Read, Update, Delete) form the backbone of your app.

✅ VS Code Setup

• Install Java 17+
• Install Maven
• Install MySQL Server
• Install VS Code with these extensions:

• Java Extension Pack
• Spring Boot Extension Pack
• Maven for Java
• Thunder Client (for API testing)
• Lombok Support

⚙️ Create Project Using Spring Initializr in VS Code

Open VS Code → Use Spring Initializr Extension → Choose:

• Project Type: Maven
• Language: Java
• Spring Boot: 3.x
• Dependencies: Spring Web, Spring Data JPA, MySQL Driver, Lombok

📁 Project Structure

src/
├── config/
│   └── SecurityConfig.java
├── controller/
│   └── UserController.java
├── dto/
│   └── UserDTO.java
├── entity/
│   └── User.java
├── repository/
│   └── UserRepository.java
├── service/
│   └── UserService.java
└── SpringAngularCrudApplication.java
  

🔁 Control Flow

Here’s how the control flows through the app:

• Client (Angular or Postman) sends HTTP requests
• Controller receives request, maps DTOs, calls Service
• Service handles business logic and file saving
• Repository handles DB interaction via JPA
• Entity represents DB table
• DTO ensures safe and efficient data transfer

💾 application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=root
spring.datasource.password=yourpassword
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
  

📦 Entity – User.java

@Entity
@Data
public class User {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;
  private String name;
  private String email;
  private String imageUrl;
}
  

🧾 DTO – UserDTO.java

@Data
public class UserDTO {
  private Long id;
  private String name;
  private String email;
  private MultipartFile image;
}
  

📁 Repository – UserRepository.java

public interface UserRepository extends JpaRepository<User, Long> {}
  

🔧 Service – UserService.java

@Service
public class UserService {
  @Autowired
  private UserRepository userRepository;

  public User saveUser(UserDTO dto) throws IOException {
    User user = new User();
    user.setName(dto.getName());
    user.setEmail(dto.getEmail());
    if (dto.getImage() != null) {
      String fileName = UUID.randomUUID() + "_" + dto.getImage().getOriginalFilename();
      Path path = Paths.get("uploads/" + fileName);
      Files.copy(dto.getImage().getInputStream(), path);
      user.setImageUrl(fileName);
    }
    return userRepository.save(user);
  }

  public List<User> getAllUsers() {
    return userRepository.findAll();
  }

  public void deleteUser(Long id) {
    userRepository.deleteById(id);
  }

  public User updateUser(Long id, UserDTO dto) throws IOException {
    User user = userRepository.findById(id).orElseThrow();
    user.setName(dto.getName());
    user.setEmail(dto.getEmail());
    if (dto.getImage() != null) {
      String fileName = UUID.randomUUID() + "_" + dto.getImage().getOriginalFilename();
      Path path = Paths.get("uploads/" + fileName);
      Files.copy(dto.getImage().getInputStream(), path, StandardCopyOption.REPLACE_EXISTING);
      user.setImageUrl(fileName);
    }
    return userRepository.save(user);
  }
}
  

🌐 Controller – UserController.java

@RestController
@RequestMapping("/api/users")
public class UserController {
  @Autowired
  private UserService userService;

  @PostMapping
  public ResponseEntity<User> createUser(@ModelAttribute UserDTO dto) throws IOException {
    return ResponseEntity.ok(userService.saveUser(dto));
  }

  @GetMapping
  public List<User> getAll() {
    return userService.getAllUsers();
  }

  @PutMapping("/{id}")
  public ResponseEntity<User> update(@PathVariable Long id, @ModelAttribute UserDTO dto) throws IOException {
    return ResponseEntity.ok(userService.updateUser(id, dto));
  }

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

🗂️ Static File Setup

@Configuration
public class WebConfig implements WebMvcConfigurer {
  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/uploads/**")
            .addResourceLocations("file:uploads/");
  }
}
  

✅ Summary

You’ve now built a complete Spring Boot backend with:

• REST APIs for user management (CRUD)
• MySQL as the persistent store
• Image uploading via MultipartFile
• Clean project structure with DTO, Entity, Repository, Service, and Controller layers
• VS Code as your lightweight, full-featured development environment