[Java知识库]SpringBoot+小程序

springboot后台

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

application.properties配置

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/mimi-boot
spring.datasource.username=root
spring.datasource.password=123456

数据库新建user表

CREATE TABLE `user` (
  `id` int NOT NULL AUTO_INCREMENT COMMENT '用户id',
  `username` varchar(50) COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '用户名',
  `password` varchar(50) COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '密码',
  `nickname` varchar(50) COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '昵称',
  `address` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT '地址',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

用户登录

User对象

@Entity
@Table(name = "user")
@Getter
@Setter
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String username;
    private String password;
    private String nickname;
    private String address;
}

登录-持久层

/**
 * 继承JpaRepository，指定一个泛型，第一个参数是实体类，第二个参数是实体类的主键类型
 */
@Repository
public interface UserRepository extends JpaRepository<User,Integer> {
}

登录-业务层

登录-控制层

@RestController
@RequestMapping("/user")
public class UserController {

    /**注入UserRepository**/
    @Resource
    private UserRepository userRepository;

    @PostMapping("/login")
    public User login(@RequestBody User user){
        return userRepository.findByUsernameAndPassword(user.getUsername(), user.getPassword());

    }

    @GetMapping("/{id}")
    public User getUserById(@PathVariable Integer id){
        Optional<User> user = userRepository.findById(id);
        /**如果查询成功返回User，否则返回null**/
        return user.orElseGet(null);
    }
}

小程序页面

npm创建Vant Weapp(官方参考文档)
添加组件

  "usingComponents": {
    "van-button": "@vant/weapp/button/index",
    "van-field": "@vant/weapp/field/index",
    "van-icon": "@vant/weapp/icon/index"
  }

数据请求request.js

// 同时发送异步请求的次数
let ajaxTimes = 0;
export const request = (params) => {
  ajaxTimes ++;
  wx.showLoading({
    title: '加载中',
    mask: true
  })
  
  // 后台的请求地址，记得修改成你自己的地址
  const baseUrl = 'http://localhost:8080';
  
  return new Promise((resolve, reject) => {
    wx.request({
      ...params,
      url: baseUrl + params.url,
      success: (result) => {
        resolve(result.data);
      },
      fail: (err) => {
        reject(err);
      },
      complete: () => {
        ajaxTimes --;
        if(ajaxTimes === 0) {  // 所有请求都完成后再关闭提示
          wx.hideLoading();
        }
      },
    })
  })
}