Mybatis的常用配置总结（个人学习总结）

1.在resource导入依赖db.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=utf8
username=root
password=123456

2.在resource添加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>

    <!--导入properties文件-->
    <properties resource="db.properties"/>
    
<!--    设置日志等-->
<!--    <settings>-->
<!--        <setting name="logImpl" value="STDOUT_LOGGING"/>-->
<!--    </settings>-->

    <!--给实体类起别名-->
<!--    <typeAliases>-->
<!--        <typeAlias type="com.kuang.pojo.User" alias="User"></typeAlias>-->
<!--    </typeAliases>-->


    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <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="123456"/>
            </dataSource>
        </environment>
    </environments>


<!--    <mappers>-->
<!--        <mapper resource="com/kuang/dao/UserMapper.xml"/>-->
<!--    </mappers>-->

</configuration>

DOM节点要求：

configuration（配置）
	properties（属性，必须在settings前面）
	settings（设置）
	typeAliases（类型别名）
	typeHandlers（类型处理器）
	objectFactory（对象工厂）
	plugins（插件，少用）
	environments（环境配置，不配多环境，基本在Spring里面配置）
	environment（环境变量）
		transactionManager（事务管理器）
		dataSource（数据源）
	databaseIdProvider（数据库厂商标识）
	mappers（映射器）

设置

3.建设filetree样式如下：

4.配置pom

<?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>

    <groupId>com.kuang</groupId>
    <artifactId>Mybatis-Study</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>mybatis-01</module>
        <module>mybatis-02</module>
        <module>mybatis-03</module>
        <module>mybatis-04</module>
    </modules>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
        </dependency>

    </dependencies>

    <!--在build中配置resources,来防止我们资源导出失败的问题-->
    <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>

5.dao

创建方法名UserMapper

package com.kuang.dao;

import com.kuang.pojo.User;

import java.util.List;

public interface UserMapper {
    //查询全部用户
    List<User> getUserList();

    //根据id查询用户
    User getUserById(int id);

    //插入一个用户
    int addUser(User user);

    //修改用户
    int updateUser(User user);

    //删除用户
    int deleteUser(int id);



}

创建对应的UserMapper.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="com.kuang.dao.UserMapper">

<!--    结果集映射-->
    <resultMap id="UserMap" type="User">
        <result column="pwd" property="password"/>
    </resultMap>
    <select id="getUserById" resultMap="UserMap">
        select *from mybatis.user where id=#{id}
    </select>
<!--    <select id="getUserList" resultType="User" >-->
<!--        select * from mybatis.user-->
<!--    </select>-->

<!--    <select id="getUserById" parameterType="int" resultType="User">-->
<!--        select * from mybatis.user where id = #{id}-->
<!--    </select>-->

<!--    <insert id="addUser" parameterType="User">-->
<!--        insert into mybatis.user(id,name,pwd) value (#{id},#{name},#{pwd});-->
<!--    </insert>-->

<!--    <update id="updateUser" parameterType="com.kuang.pojo.User">-->
<!--        update mybatis.user set name =#{name},pwd=#{pwd} where id=#{id};-->
<!--    </update>-->

<!--    <delete id="deleteUser" parameterType="int">-->
<!--        delete from mybatis.user where id=#{id};-->
<!--    </delete>-->

</mapper>

6.创建一个实体类Javabean pojo.User

有参构造器、无参构造器、get和set方法、toString

package com.kuang.pojo;

import org.apache.ibatis.type.Alias;

//别名
@Alias("user")
public class User {
    private int id;
    private String name;
    private String 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 getPwd() {
        return password;
    }

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

    public User() {
    }

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

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

7.在dao下创建一个utils（死代码）

package com.kuang.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;

//SQLSessionFactory
public class MybatisUtils {

    private static SqlSessionFactory sqlSessionFactory;

    static {
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    //获取SqlSession连接
    public static SqlSession getSession(){
        return sqlSessionFactory.openSession();
    }

}

8.test示例（增删改查）

package com.kuang.dao;

import com.kuang.pojo.User;
import com.kuang.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.HashMap;
import java.util.List;

public class UserDaoTest {

    @Test
    public void test(){
        SqlSession sqlSession = MybatisUtils.getSession();
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = userMapper.getUserList();

        for (User user : userList) {
            System.out.println(user);
        }


        //关闭sqlsession
        sqlSession.close();
    }
    @Test
    public void getUserById(){
        SqlSession sqlSession = MybatisUtils.getSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);

        User user = mapper.getUserById(1);
        System.out.println(user);


        sqlSession.close();
    }
    //增删改需要提交事务
    @Test
    public void addUser(){
        SqlSession sqlSession = MybatisUtils.getSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        int res = mapper.addUser(new User(4, "hh", "123333"));

        if (res>0){
            System.out.println("输入成功");
        }

        //提交事务
        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void updateUser(){
        SqlSession sqlSession = MybatisUtils.getSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        mapper.updateUser(new User(4,"呵呵","123123"));

        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void deleteUser(){
        SqlSession sqlSession = MybatisUtils.getSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        mapper.deleteUser(4);

        sqlSession.commit();
        sqlSession.close();
    }

    
}