1、新建一个maven我的项目

<dependencies>    <!--单元测试包-->    <denpendency>        <groupId>junit</groupId>        <artifactId>junit</artifactId>        <version>4.12</version>    </dependency>        <!--mysql-->    <denpendency>        <groupId>mysql</groupId>        <artifactId>mysql-connerctor-java</artifactId>        <version>5.1.47</version>    </dependency>    <!--mybatis-->    <denpendency>        <groupId>org.mybatis</groupId>        <artifactId>mybatis</artifactId>        <version>3.5.2</version>    </dependency>        <!--spring-->    <denpendency>        <groupId>org.springframework</groupId>        <artifactId>spring-webmvc</artifactId>        <version>5.1.9.RELEASE</version>    </dependency>        <!--Spring操作数据库的话，还须要一个spring-jdbc-->    <denpendency>        <groupId>org.springframework</groupId>        <artifactId>spring-jdbc</artifactId>        <version>5.1.9.RELEASE</version>    </dependency>        <!--aop织入-->    <denpendency>        <groupId>org.aspectj</groupId>        <artifactId>aspectjweaver</artifactId>        <version>1.8.13</version>    </dependency>    <!--mybatis-spring整合-->    <denpendency>        <groupId>org.mybatis</groupId>        <artifactId>mybatis-spring</artifactId>        <version>2.0.2</version>    </dependency>    </dependencies><build>    <resources>        <resource>            <directory>src/main/java</directory>            <includes>                <include>**/*.properties</include>                <include>**/*.xml</include>            </includes>            <filtering>true</filtering>        </resource>        <resource>            <directory>src/main/resources</directory>            <includes>                <include>**/*.properties</include>                <include>**/*.xml</include>            </includes>            <filtering>true</filtering>        </resource>    </resources></build>

2.编写配置文件

3.测试

1.1、回顾Mybatis

1.编写实体类

package com.jialidun.pojo;import lombok .Data;@Datapublic class User{    private int id;    private String name;    private String pwd;}

2.编写外围配置文件mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE configuration    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"    "http://mybatis.org/dtd/mybatis-3-config.dtd"><!--configuration外围配置文件--><configuration>    <!--别名-->    <typeAliases>        <package name="com.jialidun.pojo"/>    </typeAliases>    <environments default="development">        <environment id="development">            <transactionManager type="JDBC"/>            <dataSource type="POOLED">              <property name="driver" value="com.mysql.cj.jdbc.Driver"/>              <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8&amp;serverTimezone=Asia/Shanghai"/>              <property name="username" value="root"/>              <property name="password" value="root"/>            </dataSource>        </environment>    </environments>    <mappers>        <mapper class="com.jialidun.mapper.UserMapper"/>    </mappers></configuration>

3.编写接口

package com.jialidun.mapper;public interface UserMapper{    public List<User> selectUser();}

4.编写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"><!--configuration外围配置文件--><mapper namespace="com.jialidun.mapper.UserMapper">    <select id="selectUser" resultType="user">        select * from mybatis.user;    </select></mapper>

5.测试

public class TestDemo{    @Test    public void test01{        String resources="mybatis-config.xml";        InputStream in = Resources.getResourceAsStream(resources);        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(in);        SqlSession sqlSession = sessionFactory.openSession(true);        UserMapper mapper = sqlSession.getMapper(UserMapper.class);        List<User> userList = mapper.selectUser();        for(User user:userList){            System.out.println(user);        }    }}