一.创建maven工程,引入jar包

pom.xml

<!--MyBatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.0</version>
        </dependency>
        <!--日志-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <!--oracle数据库连接-->
        <dependency>
            <groupId>com.oracle.database.jdbc</groupId>
            <artifactId>ojdbc6</artifactId>
            <version>11.2.0.4</version>
        </dependency>
        <!--单元测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

二.在resource资源文件夹下导入log4j.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
    <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
        <param name="Encoding" value="UTF-8"/>
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%-5p %d{MM-dd HH:mm:ss,SSS} %m  (%F:%L) \n"/>
        </layout>
    </appender>
    <logger name="java.sql">
        <level value="debug"/>
    </logger>
    <logger name="org.apache.ibatis">
        <level value="info"/>
    </logger>
    <root>
        <level value="debug"/>
        <appender-ref ref="STDOUT"/>
    </root>
</log4j:configuration>

三.创建mybatis-config.xml

<?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">
<configuration>
    <!--引入log4j日志-->
    <settings>
        <setting name="logImpl" value="LOG4J"/>
    </settings>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="oracle.jdbc.driver.OracleDriver"/>
                <property name="url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/>
                <property name="username" value="scott"/>
                <property name="password" value="tiger"/>
            </dataSource>
        </environment>
    </environments>
</configuration>

四.创建Dept表的pojo类以及dao层

Dept.java

package com.etc.pojo;

/**
 * @Author Gao Xiaozhuang
 * @Date 2020/11/26  12:51
 * @Version 1.0
 * @Description
 */
public class Dept {
    private Integer deptno;
    private String dname;
    private String loc;

    public Integer getDeptno() {
        return deptno;
    }

    public void setDeptno(Integer deptno) {
        this.deptno = deptno;
    }

    public String getDname() {
        return dname;
    }

    public void setDname(String dname) {
        this.dname = dname;
    }

    public String getLoc() {
        return loc;
    }

    public void setLoc(String loc) {
        this.loc = loc;
    }

    @Override
    public String toString() {
        return "Dept{" +
                "deptno=" + deptno +
                ", dname='" + dname + '\'' +
                ", loc='" + loc + '\'' +
                '}';
    }
}

DeptDao.java

package com.etc.dao;

import com.etc.pojo.Dept;

/**
 * @Author Gao Xiaozhuang
 * @Date 2020/11/26  12:49
 * @Version 1.0
 * @Description
 */
public interface DeptDao {
    Dept selectById(int id);
}

五.在资源文件夹下创建对应dao的mapper文件

DeptMapper.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">
<!--namespace 对应dao位置-->
<mapper namespace="com.etc.dao.DeptDao">
<!--id对应dao中的方法  parameterType对应参数类型 resultType对应结果集返回类型-->
    <select id="selectById" parameterType="int" resultType="com.etc.pojo.Dept">
    select deptno,dname,loc from Dept where deptno = #{id}
  </select>
</mapper>

六.在mybatis-config.xml中引入DeptMapper.xml,加载映射文件

 <!--加载映射文件-->
    <mappers>
        <mapper resource="com.etc.dao.imp/EmpMapper.xml"/>
        <mapper resource="com.etc.dao.imp/DeptMapper.xml"/>
    </mappers>

七.在test中编写测试单元

    @Test
    public void DeptDemo() throws IOException {
        String resource = "mybatis-config.xml";
        //读取配置文件
        InputStream inputStream = Resources.getResourceAsStream(resource);
        //创建工厂
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        DeptDao deptDao = sqlSession.getMapper(DeptDao.class);
        Dept dept = deptDao.selectById(10);
        System.out.println(dept);
        sqlSession.close();
    }

八.运行结果

本文地址：https://blog.csdn.net/gxzhaha/article/details/110219071