07_product_api.md

🟢 07 - Product API

Documentation for the REST API to manage products, structured in layers: model, repository, service, and controller.

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Model

Product entity with fields id, name, and price.

package com.example.spring_boot_project.model;

import jakarta.persistence.*;

@Entity
@Table(name = "products")
public class Product {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private Double price;

    // Constructors, getters, and setters
}

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Repository

ProductRepository interface extending JpaRepository for CRUD operations.

package com.example.spring_boot_project.repository;

import com.example.spring_boot_project.model.Product;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface ProductRepository extends JpaRepository<Product, Long> {}

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Service

ProductService class with CRUD methods for products.

package com.example.spring_boot_project.service;

import com.example.spring_boot_project.model.Product;
import com.example.spring_boot_project.repository.ProductRepository;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Optional;

@Service
public class ProductService {
private final ProductRepository productRepository;

    public ProductService(ProductRepository productRepository) {
        this.productRepository = productRepository;
    }

    public List<Product> getAllProducts() { return productRepository.findAll(); }
    public static Optional<Product> getProductById(Long id) { return productRepository.findById(id); }
    public Product saveProduct(Product product) { return productRepository.save(product); }
    public void deleteProduct(Long id) { productRepository.deleteById(id); }
}

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Controller

Exposes REST endpoints:

• GET /api/products/list — lists all products
• GET /api/products/{id} — get product by ID
• POST /api/products — create product
• DELETE /api/products/{id} — delete product

package com.example.spring_boot_project.controller;

import com.example.spring_boot_project.model.Product;
import com.example.spring_boot_project.service.ProductService;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/api/products")
public class ProductController {
private final ProductService productService;

    public ProductController(ProductService productService) { this.productService = productService; }

    @GetMapping("/list")
    public List<Product> getAllProducts() { return productService.getAllProducts(); }

    @GetMapping("/{id}")
    public ResponseEntity<Product> getProductById(@PathVariable Long id) {
        return ProductService.getProductById(id)
                .map(ResponseEntity::ok)
                .orElse(ResponseEntity.notFound().build());
    }

    @PostMapping
    public Product createProduct(@RequestBody Product product) { return productService.saveProduct(product); }

    @DeleteMapping("/{id}")
    public ResponseEntity<Void> deleteProduct(@PathVariable Long id){
        productService.deleteProduct(id);
        return ResponseEntity.noContent().build();
    }
}

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