太卷了！现在面试上来就问SpringBoot源码实现，CRUD工程师能招架得住吗今晚这节SpringBoot直播课千万不能错过，听完就能掌握SpringBoot源码，征服面试官

demo代码：

新建工程 springBoot1.5+Web+JPA+MYSQL+JDBC

目录结构

1、新建一个实体类User

//使用JPA注解配置映射关系@Entity//告诉JPA这是一个实体类（和数据表映射的类）@Table(name="tbl_user") //@Table来指定和那个数据表对应，如果省略默认表明就是user;public class User {    @Id //这是一个主键    @GeneratedValue(strategy = GenerationType.IDENTITY)//自增组件    private Integer id ;    @Column(name="last_name",length = 50) //这是和数据表对应的一个列    private String lastName;    @Column//省略默认列名就是属性名    private String email;    @Column    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    public String getLastName() {        return lastName;    }    public void setLastName(String lastName) {        this.lastName = lastName;    }    public String getEmail() {        return email;    }    public void setEmail(String email) {        this.email = email;    }}

2、新建一个UserRepository来继承jpa的绝大多数功能

//继承jpaRepositorypublic interface UserRepository extends JpaRepository<User,Integer> {}

3、编写配置文件application.yml

spring:  datasource:    url: jdbc:mysql://192.168.179.131/jpa    username: root    password: Welcome_1    driver-class-name: com.mysql.jdbc.Driver  jpa:    hibernate:    #更新或创建      ddl-auto: update    show-sql: true

4、编写Controller测试

@RestControllerpublic class UserController {    @Autowired    UserRepository userRepository;    @GetMapping("/user/{id}")    public User getUser(@PathVariable("id") Integer id){        User user = userRepository.findOne(id);        return user;    }    @GetMapping("/insert")    public User insertUser(User user){        User user1 = userRepository.save(user);        return  user1;    }}