<dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.7</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.26</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.14.1</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.7.0</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

package com.xiongshou.domain;

import java.io.Serializable;
import java.util.Date;

public class User implements Serializable {//序列化
    private Integer id;
    private  String username;
    private Date brithday;
    private String sex;
    private String address;

    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Date getBrithday() {
        return brithday;
    }

    public void setBrithday(Date brithday) {
        this.brithday = brithday;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", brithday=" + brithday +
                ", sex='" + sex + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

package com.xiongshou.dao;

import com.xiongshou.domain.User;

import java.util.List;

public interface IUserDao {
    /**
     * 查询表中所有
     * @return
     */
    List<User> FindAll();
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<!--mybatis主配置文件-->
<configuration>
    <!-- 配置环境 -->
    <environments default="mysql">
        <!--配置mysql环境-->
        <environment id="mysql">
            <!--配置事务-->
            <transactionManager type="JDBC"></transactionManager>
            <!--配置数据源（连接池）-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
                <property name="username" value="root"/>
                <property name="password" value="adminadmin"/>
            </dataSource>
        </environment>
    </environments>
    <!--指定映射配置文件，即每个dao独立的配置文件-->
    <mappers>
        <mapper resource="com/xiongshou/dao/IUserDao.xml"/>
    </mappers>
</configuration>

<?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="com.xiongshou.dao.IUserDao">
    <!--配置查询所有  id为方法名称-->
    <select id="FindAll" resultType="com.xiongshou.domain.User">
        select *
        from user;
    </select>
</mapper>

package com.xionghsou.test;

import com.xiongshou.dao.IUserDao;
import com.xiongshou.domain.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * 入门案例
 */
public class MybatisTest {
    public static void main(String[] args) throws IOException {
        //1.读取配置文件
        InputStream in= Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.创建SqlsessionFactory工厂
        SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
        SqlSessionFactory factory=builder.build(in);
        //3.使用工厂生产Sqlsession对象
        SqlSession session=factory.openSession();
        //4。使用Sqlsession创建dao接口的代理对象
        IUserDao userDao=session.getMapper(IUserDao.class);
        //5.使用代理对象执行方法
        List<User> list=userDao.FindAll();
        for (User i: list) {
            System.out.println(i);
        }
        //6.释放资源
        session.close();
        in.close();
    }
}

    <!--指定映射配置文件，即每个dao独立的配置文件-->
    <mappers>
        <mapper class="com.xiongshou.dao.IUserDao"/>
    </mappers>