Spring Boot 3.0 GA 正式版尝鲜之增删改查（CURD）Kotlin版 (gradle)

1. 创建工程

2. gradle开启snapshots库 repositories增加如下库

   repositories {
       maven("https://oss.sonatype.org/content/repositories/snapshots/")
   }
   

3. 增加依赖

   implementation("com.zaxxer:HikariCP")
   implementation("com.baomidou:mybatis-plus-boot-starter:3.5.2.7-SNAPSHOT")
   implementation ("cn.hutool:hutool-all:5.8.10")
   

4. 跨域访问配置，创建WebAppConfig类，填入如下内容，

   @Configuration
   class WebConfig {
       @Bean
       fun corsFilter(): CorsFilter? {
           val source = UrlBasedCorsConfigurationSource()
           val config = CorsConfiguration()
   
           // 允许跨域的头部信息
           config.addAllowedHeader("*")
           // 允许跨域的方法
           config.addAllowedMethod("*")
           // 可访问的外部域
           config.addAllowedOrigin("*")
           // 需要跨域用户凭证（cookie、HTTP认证及客户端SSL证明等）
           //config.setAllowCredentials(true);
           //config.addAllowedOriginPattern("*");
   
           // 跨域路径配置
           source.registerCorsConfiguration("/**", config)
           return CorsFilter(source)
       }
   }
   

5. 打开dbeaver（本人使用的数据库客户端工具），连接数据并创建数据库（spring-boot3-demo）, 并执行如下语句

   DROP TABLE IF EXISTS user;
   
   CREATE TABLE user
   (
       id BIGINT(20) NOT NULL COMMENT '主键ID',
       name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
       age INT(11) NULL DEFAULT NULL COMMENT '年龄',
       email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
       PRIMARY KEY (id)
   );
   

6. 填入数据库配置 application.yml

   spring:
     datasource:
       type: com.zaxxer.hikari.HikariDataSource
       driver-class-name: com.mysql.cj.jdbc.Driver
       username: demo
       password: demo
       url: jdbc:mysql://server.com:3306/spring-boot3-demo
   
   mybatis-plus:
     configuration:
       log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
   

7. 创建controller，service，model，mapper

   • UserController

     package cloud.mgl.controller
     
     import cloud.mgl.model.User
     import cloud.mgl.service.UserService
     import cn.hutool.json.JSONUtil
     import org.springframework.beans.factory.annotation.Autowired
     import org.springframework.web.bind.annotation.GetMapping
     import org.springframework.web.bind.annotation.PathVariable
     import org.springframework.web.bind.annotation.PostMapping
     import org.springframework.web.bind.annotation.PutMapping
     import org.springframework.web.bind.annotation.RestController
     
     @RestController
     class UserController {
     
     
         @Autowired
         private lateinit var service: UserService
     
         @GetMapping("/")
         fun home(user: User): String {
             val list = service.query(user)
             return JSONUtil.toJsonStr(list)
         }
     
         @PutMapping("/")
         fun put(user: User): String {
             val list = service.update(user)
             return JSONUtil.toJsonStr(list)
         }
     
         @PostMapping("/")
         fun post(user: User): String {
             val list = service.add(user)
             return JSONUtil.toJsonStr(list)
         }
     
         @GetMapping("/{id}")
         fun get(@PathVariable("id") id: Long): String {
             val user = service.get(id)
             return JSONUtil.toJsonStr(user)
         }
     
     }
     

   • UserService

     package cloud.mgl.service
     
     import cloud.mgl.model.User
     
     interface UserService {
         fun add(user: User)
         fun delete(id: Long)
         fun update(user: User)
         fun query(user: User): MutableList<User>
         fun get(id: Long): User?
     }
     

   • UserServiceImpl

     package cloud.mgl.service.impl
     
     import cloud.mgl.mapper.UserMapper
     import cloud.mgl.model.User
     import cloud.mgl.service.UserService
     import cn.hutool.core.bean.BeanUtil
     import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper
     import org.springframework.beans.factory.annotation.Autowired
     import org.springframework.stereotype.Service
     
     @Service
     class UserServiceImpl: UserService {
     
         @Autowired
         private lateinit var mapper: UserMapper
     
     
         override fun add(user: User) {
             mapper.insert(user)
         }
     
         override fun delete(id: Long) {
             mapper.deleteById(id)
         }
     
         override fun update(user: User) {
             mapper.updateById(user)
         }
     
         override fun query(user: User): MutableList<User> {
     
             val params = QueryWrapper<User?>()
     
             val userMap = BeanUtil.beanToMap(user,false,true)
     
             params.allEq(userMap)
     
             val list = mapper.selectList(params)
     
     
             list.forEach {
                 println(it.age)
             }
             return list
         }
     
         override fun get(id: Long): User? {
             return mapper.selectById(id)
         }
     }
     

   • UserMapper

     package cloud.mgl.mapper
     
     import cloud.mgl.model.User
     import com.baomidou.mybatisplus.core.mapper.BaseMapper
     
     interface UserMapper :BaseMapper<User> {
     }
     

   • UserModel

     package cloud.mgl.model
     
     class User {
         var id: Long? = null
         var name: String? = null
         var age: Int? = null
         var email: String? = null
     }
     

8. 启动类上面添加 @MapperScan("cloud.mgl.mapper") , 并启动程序即可

打包二进制

• 未来可期

源码地址

• https://github.com/mgl-pub/spring-boot-3.x