Kotlin+SpringBoot服务端restful框架搭建（2）集成mybatis

时间 2019-11-05

标签 kotlin+springboot kotlin springboot 服务 restful 框架搭建集成 mybatis 栏目 Spring 繁體版

原文原文链接

搭建完成简单的kotlin集成SpringBoot的框架，咱们再来尝试把mybatis也集成进去，数据库咱们采用mysql。java

要求

mybatis
mysql

快速搭建

建立一张表，表名ca_order

ID int
订单编号 order_no varchar(10)
订单金额 order_amount double
订单建立时间 create_time datetime
订单建立人 create_user varchar(10)
支付方式 pay_type varchar(10)
商品名称 commodity_name varchar(30)
商品数量 commodity_num int

DROP TABLE IF EXISTS `ca_order`;
CREATE TABLE `ca_order` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `order_no` varchar(20) DEFAULT NULL,
  `order_amount` double(10,2) DEFAULT NULL,
  `create_time` datetime DEFAULT NULL,
  `create_user` varchar(20) DEFAULT NULL,
  `pay_type` varchar(10) DEFAULT NULL,
  `commodity_name` varchar(20) DEFAULT NULL,
  `commodity_num` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;


INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1001', 1000, NOW(), '张三', '支付宝', '手机', 1);
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1002', 2799.00, NOW(), '张小凡', '支付宝','荣耀v10',1); 
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1003', 16863.00, NOW(), '郭靖', '银联', 'iPhoneX', 2);
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1004', 2677.00, NOW(), '张三风', '支付宝', 'vivoX21',1);
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1005', 4325.78, NOW(), '谢逊', '微信', '诺基亚', 3);
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1006', 2001, NOW(), '杨过', '支付宝', '小米mix', 2);
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1007', 4399.00, NOW(), '张无忌', '微信', '华为P20',1);
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1008', 2999, NOW(), '陈震', '支付宝', '荣耀v9', 3);
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1009', 1999, NOW(), '李狗蛋', '信用卡', '小米6',1);
INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES ('1010', 3200, NOW(), '郭德纲', '支付宝', 'iPhone6s', 1);

在application.yml添加datasource

spring:
  datasource:
     url: jdbc:mysql://127.0.0.1:3306/csdata?useUnicode=true&characterEncoding=utf-8
     username: root
     password: 123456
     driverClassName: com.mysql.jdbc.Driver

引入咱们须要的mybatis和mysqlmysql

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
 </dependency>
 <dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.34</version>
 </dependency>

建立实体类。kotlin建立实体类方式有两种，一种是相似java的class，一种是kotlin的data class(数据类)。数据类(data class)必须知足如下要求:

主构造函数至少有一个参数;
主构造函数的全部参数需标记为val 或 var;
数据类不能是抽象、开放、密封或者内部的;
自kotlin 1.1起,数据类能够扩展其余类;在1.1以前,数据类只能实现接口

编译器会为数据类(data class)自动生成如下函数:web

equals()/hashCode()
toString()
componentN()
copy()

lateinit只能用于非基本数据类型。Kotlin会使用null来对每个用lateinit修饰的属性作初始化，而基础类型是没有null类型。spring

class

class CaOrder {
    var id:Int=0
    var orderNo:String=""
    var orderAmount:Double=0.00
    var createTime:String=""
    var createUser:String=""
    var payType:String=""
    var commodityName:String=""
    var commodityNum:Int=0
}

开始使用lateinit var定义属性，可是运行的时候提示lateinit property has not been initialized，目前没找到解决方法，就直接给属性设置个默认值了sql

data class

data class CaOrder(
        var id:Int?,
        var orderNo:String,
        var orderAmount:Double?,
        var createTime:String,
        var createUser:String,
        var payType:String,
        var commodityName:String,
        var commodityNum:Int?
)

注意：Int后面的?号，若是不加这个问号，运行的时候会报No constructor found in void matching的错误。缘由是Int是kotlin的基础数据类型不能为null，会被映射成java中int，而实体类对应数据的时候某些字段会出现空值的，这就使kotlin在转成实体类的时候不肯定转成int仍是Integer，而加上问号以后是告诉它这个属性为空值的时候就返回null。具体能够参考一下kotlin的?的使用方法。数据库

建立Mapper，两种方式来实现Mapper，一种是经过注解标签@select,@insert,@update,@delete，另外一种经过xml配置文件，仍是推荐使用xml吧，使用起来相对方便，动态sql写起来更容易。

第一种。apache

实体类CaOrderDao微信

package com.kotliner.demo.mapper

import com.kotliner.demo.entity.CaOrder
import org.apache.ibatis.annotations.*

@Mapper
interface CaOrderMapper{

    @Select("""
        select id,order_no as orderNo, order_amount, date_format(create_time,'%Y-%m-%d %H:%i:%s') as create_time, create_user, pay_type, commodity_name, commodity_num from ca_order
        """)
    fun findOrderList(order: CaOrder):List<CaOrder>;


    @Insert("""
        INSERT INTO ca_order (order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num) VALUES
        (#{orderNo},#{orderAmount},NOW(),#{createUser},#{payType},#{commodityName},#{commodityNum})
    """)
    fun saveOrder(order: CaOrder):Int;


    @Update("""
        update ca_order set order_amount=#{orderAmount} where id=#{id}
    """)
    fun updateOrder(order: CaOrder):Int;

    @Delete("""
        delete from ca_order where id=#{id}
    """)
    fun deleteOrder(id:Int)
}

第二种，若是使用这种须要再application.yml添加以下代码用来指定xml位置mybatis

mybatis:
  type-aliases-package: com.kotliner.demo.entity
  mapper-locations: classpath:mapper/*.xml

这时候mapperr类就变得简单了app

package com.kotliner.demo.mapper

import com.kotliner.demo.entity.CaOrder
import org.apache.ibatis.annotations.Mapper

@Mapper
interface CaOrderMapper{

    fun findOrderList(order: CaOrder):List<CaOrder>;
    fun saveOrder(order: CaOrder):Int;
    fun updateOrder(order: CaOrder):Int;
    fun deleteOrder(id:Int);
}

而后在resource下面建立Mapper文件，放入xml文件

<mapper namespace="com.kotliner.demo.mapper.OrderMapper">

    <!-- 实体类映射-->
    <resultMap type="com.kotliner.demo.entity.CaOrder"   id="OrderMap">
        <result column="id" property="id"/>
        <result column="order_no" property="orderNo"/>
        <result column="order_amount" property="orderAmount"/>
        <result column="create_time" property="createTime"/>
        <result column="create_user" property="createUser"/>
        <result column="pay_type" property="payType"/>
        <result column="commodity_name" property="commodityName"/>
        <result column="commodity_num" property="commodityNum"/>
    </resultMap>
    <!-- 按条件查询-->

    <select id="findOrderList" parameterType="com.kotliner.demo.entity.CaOrder" resultMap="OrderMap" >
        select id,order_no, order_amount, create_time, create_user, pay_type, commodity_name, commodity_num from ca_order
    </select>


</mapper>

5.建立service和controller

服务接口ICaOrderService

package com.kotliner.demo.service

import com.kotliner.demo.entity.CaOrder


interface ICaOrderService{

    fun findAllOrder(order: CaOrder):List<CaOrder>;

    fun saveOrder(order: CaOrder):Int;

    fun updateOrder(order: CaOrder):Int;

    fun deleteOrder(id: Int);
}

服务实现类CaOrderMapper

package com.kotliner.demo.service


import com.kotliner.demo.entity.CaOrder
import com.kotliner.demo.mapper.CaOrderMapper
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.stereotype.Service


@Service
class CaOrderImpl : ICaOrderService {

    @Autowired
    lateinit  var dao: CaOrderMapper;

    override fun findAllOrder(order: CaOrder): List<CaOrder> {
        return dao.findOrderList(order);

    }

    override fun saveOrder(order: CaOrder): Int {
        return dao.saveOrder(order);
    }

    override fun updateOrder(order: CaOrder): Int {
        return dao.updateOrder(order);
    }

    override fun deleteOrder(id: Int) {
        dao.deleteOrder(id);
    }

}

注解的使用同java相同，只是具体方法属性定义须要注意

OrderController类

package com.kotliner.demo.controller

import com.kotliner.demo.entity.CaOrder
import com.kotliner.demo.mapper.OrderMapper
import com.kotliner.demo.service.ICaOrderService
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.web.bind.annotation.*


@RestController
class OrderController{

    @Autowired
    lateinit var service: ICaOrderService


    @RequestMapping(value = "/findAllOrder",method = arrayOf(RequestMethod.POST))
    fun findAllOrder(@RequestBody order: CaOrder):List<CaOrder>{
        return service.findAllOrder(order);
    }

    @RequestMapping(value = "/save",method = arrayOf(RequestMethod.POST))
    fun save(@RequestBody order: CaOrder):Int{
        return service.saveOrder(order);
    }

    @RequestMapping(value = "/update",method = arrayOf(RequestMethod.POST))
    fun update(@RequestBody order: CaOrder):Int{
        return service.updateOrder(order);
    }
    @RequestMapping(value = "/delete",method = arrayOf(RequestMethod.GET))
    fun delete(@RequestParam(value = "id") id:Int){
        service.deleteOrder(id);
    }
}

建立完成，启动一下服务。

建立的接口基本都是post的方式，咱们经过postman来调试接口。