1、Maven 依赖

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>constxiong</groupId>
        <artifactId>demo</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <artifactId>mybatis-spring</artifactId>

    <dependencies>
        <!-- MySQL 8.0.21 驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.21</version>
        </dependency>

        <!-- MyBatis -->
        <dependency>
		  <groupId>org.mybatis</groupId>
		  <artifactId>mybatis</artifactId>
		  <version>3.5.5</version>
		</dependency>

        <!-- MyBatis-Spring -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.5</version>
        </dependency>

        <!-- spring context -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.9.RELEASE</version>
        </dependency>

        <!-- spring jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.9.RELEASE</version>
        </dependency>

    </dependencies>

    <build>

    </build>
</project>

2、Spring 配置文件

<?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
        http://www.springframework.org/schema/context/spring-context-4.3.xsd
        ">

    <context:property-placeholder location="classpath:db.properties" ignore-unresolvable="true" />

    <bean id="dataSource" class="org.apache.ibatis.datasource.pooled.PooledDataSource">
        <!-- 基本属性 url、user、password -->
        <property name="driver" value="${jdbc_driver}" />
        <property name="url" value="${jdbc_url}"/>
        <property name="username" value="${jdbc_username}"/>
        <property name="password" value="${jdbc_password}"/>
    </bean>

    <!-- spring 和 Mybatis整合 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="mapperLocations" value="classpath:constxiong/mapper/*.xml" />
    </bean>

    <!-- DAO接口所在包，配置自动扫描 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="constxiong.mapper"/>
    </bean>

</beans>

3、db配置

#5.0 5.7
#jdbc_driver=com.mysql.jdbc.Driver
#jdbc_url=jdbc\:mysql\://localhost\:3306/blog?useUnicode\=true&allowMultiQueries\=true&characterEncoding\=UTF-8&zeroDateTimeBehavior\=convertToNull
#jdbc_username=root
#jdbc_password=root

#8.0.21
jdbc_driver=com.mysql.cj.jdbc.Driver
jdbc_url=jdbc\:mysql\://localhost\:3306/constxiong?serverTimezone\=UTC&useSSL\=false&useUnicode\=true&characterEncoding\=UTF-8
jdbc_username=root
jdbc_password=constxiong@123

3、Mapper 接口

package constxiong.mapper;

import constxiong.po.User;

import java.util.List;

/**
 * UserMapper 接口，映射对数据库的操作
 */
public interface UserMapper {

    List<User> selectUsers();

    int insertUser(User user);

    int deleteUsers();

}

4、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="constxiong.mapper.UserMapper">

    <select id="selectUsers" resultType="constxiong.po.User">
        select * from user
    </select>

    <insert id="insertUser" parameterType="constxiong.po.User">
        insert into user values(#{id}, #{name})
    </insert>

    <delete id="deleteUsers">
      delete from user
    </delete>

</mapper>

5、User PO

package constxiong.po;

/**
 * 用户表模型
 */
public class User {
    private Integer id;

    private String name;

    private String mc;

    public User(Integer id, String name) {
        this.id = id;
        this.name = name;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getMc() {
        return mc;
    }

    public void setMc(String mc) {
        this.mc = mc;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", mc='" + mc + '\'' +
                '}';
    }
}

6、测试代码