spring boot写java web和接口
流程:
Springboot开发过程
还有一个是mybatis
的依赖
测试接口
@RestController public class Hello { @RequestMapping("/hello") public String hello(){ return "helloworld"; } }
***.yml文件配置
spring: datasource: driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://localhost:3306/student?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=Asia/Shanghai username: root password: 123456 mybatis: mapper-locations: classpath:mapper/*.xml
数据库字段:
pojo
@Data public class User { private int id ; private String name; private int age; private String email; *****
剩下的就是get
和set
方法自行完成
mapper
@Mapper public interface UserMapper { List<User> findAll(); }
如果是springboot
,在启动类中使用@MapperScan
(“mapper接口所在包全名”)即可,不用一个一个的在Mapper接口中加@Mapper注解。@Mapper注解是识别他为mybatis的mapper接口,会自动的把 加@Mapper 注解的接口生成动态代理类。
让springboot
认识你的mapper层,也可以在启动类上面加MapperScan
(“mapper层所在包的全名”)
mapper.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.liuyang.mapper.UserMapper"> <select id="findAll" resultType="com.liuyang.entity.User"> SELECT * FROM user </select> </mapper>
controller
@RestController public class UserController { @Autowired //把userService实例化 private UserService userService; @RequestMapping("/user") public List<User> getUser(){ return userService.findAll(); } }
注意一定要把userService
注入到容器中
数据成功拿到
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