一、pom.xml添加mybatis-plus相关依赖

 <dependency>
      <groupId>com.baomidougroupId>
      <artifactId>mybatis-plusartifactId>
      <version>3.4.2version>
    dependency>

   <dependency>
      <groupId>com.alibabagroupId>
      <artifactId>druidartifactId>
      <version>1.1.22version>
    dependency>

   <dependency>
      <groupId>org.elasticsearchgroupId>
      <artifactId>elasticsearchartifactId>
      <version>2.4.1version>
    dependency>

二、新建数据库连接配置文件database.properties

三、调整配置文件applicationContext.xml，添加mybatis-plus数据库对应配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd">

    
    <context:component-scan base-package="com.kongpkp.infrastructure"/>

    
    <context:property-placeholder location="classpath:database.properties"/>
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${user}"/>
        <property name="password" value="${password}"/>
    bean>

    
    <bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>

        <property name="configuration">
            <bean class="com.baomidou.mybatisplus.core.MybatisConfiguration">
                <property name="autoMappingBehavior" value="FULL"/>
                <property name="mapUnderscoreToCamelCase" value="true"/>
            bean>
        property>
        
        <property name="plugins">
            <array>
                <bean class="com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor">
                    <property name="dbType" value="MYSQL"/>
                bean>
            array>
        property>
    bean>

    
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.kongpkp.infrastructure.mapper"/>
    bean>

beans>

配置调整好之后，我们后续就在项目中进行数据库操作

四、新建service，mapper，impl

四.一、新建service

public interface CouponService {
    public Coupon getCouponByGuid(String guid);
}

四.二、新建mapper用于操作dao

public interface BusinessMapper extends BaseMapper {
}

四.三、新建impl用于实现service

@Service
public class CouponImpl implements CouponService {

    @Autowired
    private CouponMapper couponMapper;

    @Override
    public Coupon getCouponByGuid(String guid){
        QueryWrapper wrapper = new QueryWrapper<>();
        wrapper.eq("guid",guid);
        Coupon coupon =   couponMapper.selectOne(wrapper);
        return  coupon;
    }
}

四.四、在controller中实际操作数据

@Controller
@RequestMapping("/index")
public class IndexController{

    @Autowired
    CouponService couponService;

    @RequestMapping("/index")
    public ModelAndView index(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception {
        Coupon coupon = new Coupon();
        coupon =  couponService.getCouponByGuid("24bed1d2-f732-11ea-bac5-62fdb9de135c");
        System.out.println(JSON.toJSONString(coupon));
        return new ModelAndView("index");

 } 
}