day02_springboot综合案例

**Day02 SpringBoot 综合案例**

在前面的两天，我们已经学习了Spring Boot的基本概念、配置文件、依赖管理以及RESTful API等内容。今天，我们将综合这些知识，来构建一个完整的Spring Boot应用。

**案例描述**

我们的案例是一个简单的在线商城系统，包含以下功能：

* 用户注册和登录* 商品列表展示* 商品详情展示* 购物车管理**项目结构**

首先，我们需要创建一个新的Spring Boot项目。我们使用Spring Initializr来创建一个新项目。

java// pom.xml<dependencies>
 <!-- Spring Boot Starter Web -->
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-web</artifactId>
 </dependency>

 <!-- MySQL Connector -->
 <dependency>
 <groupId>mysql</groupId>
 <artifactId>mysql-connector-java</artifactId>
 <scope>runtime</scope>
 </dependency>

 <!-- Spring Boot Starter Test -->
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-test</artifactId>
 <scope>test</scope>
 </dependency>
</dependencies>

properties# application.propertiesspring.datasource.url=jdbc:mysql://localhost:3306/mydbspring.datasource.username=rootspring.datasource.password=123456spring.jpa.hibernate.ddl-auto=updateserver.servlet.context-path=/online-shop

java// User.java@Entitypublic class User {
 @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
 private Long id;

 private String username;
 private String password;

 // getters and setters}

java// Product.java@Entitypublic class Product {
 @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
 private Long id;

 private String name;
 private Double price;

 // getters and setters}

java// UserService.java@Servicepublic class UserService {
 @Autowired private UserRepository userRepository;

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

 public User getUserById(Long id) {
 return userRepository.findById(id).orElse(null);
 }
}

java// ProductService.java@Servicepublic class ProductService {
 @Autowired private ProductRepository productRepository;

 public List getAllProducts() {
 return productRepository.findAll();
 }

 public Product getProductById(Long id) {
 return productRepository.findById(id).orElse(null);
 }
}

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

 @GetMapping public List getAllUsers() {
 return userService.getAllUsers();
 }

 @GetMapping("/{id}")
 public User getUserById(@PathVariable Long id) {
 return userService.getUserById(id);
 }
}

java// ProductController.java@RestController@RequestMapping("/products")
public class ProductController {
 @Autowired private ProductService productService;

 @GetMapping public List getAllProducts() {
 return productService.getAllProducts();
 }

 @GetMapping("/{id}")
 public Product getProductById(@PathVariable Long id) {
 return productService.getProductById(id);
 }
}

java// CartController.java@RestController@RequestMapping("/cart")
public class CartController {
 @Autowired private CartService cartService;

 @PostMapping public Cart addProductToCart(@RequestBody Product product) {
 return cartService.addProductToCart(product);
 }

 @GetMapping public List getAllCarts() {
 return cartService.getAllCarts();
 }
}