idea配置MyBatis

新建工程

删掉src

创建Module

在工程中的porn.xml输入以下依赖

<?xml version="1.0" encoding="UTF-8"?>
<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>

    <!--父工程-->
    <groupId>org.example</groupId>
    <artifactId>MyBatis_Study</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>test01</module>
    </modules>
    <!--导入依赖-->
    <dependencies>
        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.9</version>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.1</version>
        </dependency>
        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
        <java.version>14</java.version>
        <maven.compiler.source>14</maven.compiler.source>
        <maven.compiler.target>14</maven.compiler.target>
    </properties>
</project>

Module中的porn.xml中输入

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>MyBatis_Study</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.shao</groupId>
    <artifactId>test01</artifactId>

    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>

</project>

右边MAVEN点击刷新

在test01/src/main/resources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>
    <!--  JavaBean类型自动映射扫描包配置 Java类型别名  -->
    <typeAliases>
        <package name="com.brok1n.web.java.springmvcdemo1.bean"/>
        <!--<typeAlias alias="User" type="com.brok1n.web.java.springmvcdemo1.bean.User" />-->
    </typeAliases>

    <environments default="development">
        <!-- 数据库环境 -->
        <environment id="development">
            <!-- 使用JDBC使用管理 -->
            <transactionManager type="JDBC"/>
            <!-- 数据源配置 -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=utf8"/>
                <property name="username" value="root"/>
                <property name="password" value="333"/>
            </dataSource>
        </environment>
    </environments>
    <!-- 映射器 , 每一个mapper.xml都需要在mybatis-config中注册-->
    <mappers>
        <mapper resource="com/shao/dao/UserMapper.xml"/>
    </mappers>
</configuration>

在test01/src/main/java创建三个文件夹dao、pojo、utils

在utils创建MybatisUtils

package com.shao.utils;

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;

public class MybatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            //获取SQLSessionFactory
            String resoure = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resoure);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }
}

pojo创建User

package com.test.pojo;
//实体类
public class User {
    private int id;
    private String name;
    private String password;

    public User() {
    }

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

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

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

在DAO中创建UserDao接口和UserMapper.xml

//UserDao
package com.test.dao;

import com.test.pojo.User;

import java.util.List;

public interface UserDao {
    List<User> getUserList();
}

<?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绑定一个dao/mapper接口 -->
<mapper namespace="com.test.dao.UserDao">
    <select id="getUserList" resultType="com.test.pojo.User">
        select * from user
    </select>

</mapper>

在test/java中创建test/dao.测试

package com.test.dao;

import com.test.pojo.User;
import com.test.utils.MybatisUtils;
import junit.framework.TestCase;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;

public class UserDaoTest extends TestCase {
    @Test
    public void test(){
        //获取SqlSession对象
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        List<User> userList = userDao.getUserList();
        for (User user:userList) {
            System.out.println(user);
        }
        sqlSession.close();
    }

}

一些坑

记得连接MySQL，且连接的table必须和配置一致



读错要从后往前读！