SpringBoot+MySQL(官方案例)

1. 在线文档
2. 项目结构

   1.源码克隆：git clone https://github.com/spring-guides/gs-accessing-data-mysql.git
   2.包含两个项目initial和complete，initial可以根据文档练习完善，complete是完整项目
   3.功能描述：构建应用程序，并将其连接到MySQL数据库，使用 Spring Data JPA 来访问数据库
   4.MySQL安装：https://blog.csdn.net/tongxin_tongmeng/article/details/127485630
   5.MySQL数据库和用户创建及授权：
   mysql> create database db_example; -- Creates the new database
   mysql> create user 'springuser'@'%' identified by 'ThePassword'; -- Creates the user
   mysql> grant all on db_example.* to 'springuser'@'%'; -- Gives all privileges to the new user on the newly created database
   5.MySQL数据库连接配置(application.properties)：
   spring.jpa.hibernate.ddl-auto=update
   spring.datasource.url=jdbc:mysql://${MYSQL_HOST:localhost}:3306/db_example
   spring.datasource.username=springuser
   spring.datasource.password=ThePassword
   spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

   

3. 源码分析

   1.POM依赖
   
   	
   	
   		org.springframework.boot
   		spring-boot-starter-data-jpa
   	
   	
   		org.springframework.boot
   		spring-boot-starter-web
   	
   	
   	
   		mysql
   		mysql-connector-java
   		runtime
   	
   	
   		org.springframework.boot
   		spring-boot-starter-test
   		test
   	
   

   2.POJO类
   @Entity // This tells Hibernate to make a table out of this class
   public class User {
   	@Id
   	@GeneratedValue(strategy=GenerationType.AUTO)
   	private Integer id;
   
   	private String name;
   
   	private String email;
   
   	public Integer getId() {
   		return id;
   	}
   
   	public void setId(Integer id) {
   		this.id = id;
   	}
   
   	public String getName() {
   		return name;
   	}
   
   	public void setName(String name) {
   		this.name = name;
   	}
   
   	public String getEmail() {
   		return email;
   	}
   
   	public void setEmail(String email) {
   		this.email = email;
   	}
   }

   3.接口类
   public interface UserRepository extends CrudRepository {
   
   }

   4.控制器
   @Controller	// This means that this class is a Controller
   @RequestMapping(path="/demo") // This means URL's start with /demo (after Application path)
   public class MainController {
   	@Autowired // This means to get the bean called userRepository
   			   // Which is auto-generated by Spring, we will use it to handle the data
   	private UserRepository userRepository;
   
   	@PostMapping(path="/add") // Map ONLY POST Requests
   	public @ResponseBody String addNewUser (@RequestParam String name
   			, @RequestParam String email) {
   		// @ResponseBody means the returned String is the response, not a view name
   		// @RequestParam means it is a parameter from the GET or POST request
   
   		User n = new User();
   		n.setName(name);
   		n.setEmail(email);
   		userRepository.save(n);
   		return "Saved";
   	}
   
   	@GetMapping(path="/all")
   	public @ResponseBody Iterable getAllUsers() {
   		// This returns a JSON or XML with the users
   		return userRepository.findAll();
   	}
   }

4. 项目演示