MyBatis项目相关配置（IDEA）

1.创建一个普通的Maven项目
2.删除src目录
3.在父项目的pom.xml导入依赖

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

        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

    </dependencies>

4.new Module
5.编写MyBatis核心配置文件
在resources目录下新建mybatis-config.xml

<!--核心配置文件-->
<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <!--每一个Mapper.XML都需要在Mybatis核心配置文件中注册！-->
    <mappers>
        <mapper resource="com/jx/dao/UserMapper.xml"/>
    </mappers>
</configuration>

6.编写MyBatis工具类

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-->sqlSession
public class MybatisUtils {
    private  static SqlSessionFactory sqlSessionFactory;
    static {
        String resource = "mybatis-config.xml";
        try {
            InputStream inputStream = Resources.getResourceAsStream(resource);
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    //既然有了sqlSessionFactory，顾名思义就可以从中获得SqlSession的实例了
    //SqlSession完全包含了面向数据库执行SQL命令所需要的所有方法
    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();

    }
}

7.创建实体类

public class User {
    private int id;
    private String name;
    private String pwd;

    public User() {
    }

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

    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 pwd;
    }

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

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

8.编写Mapper接口类

import com.pojo.User;

import java.util.List;

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

9.编写Mapper.xml的配置文件

<?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.jx.dao.UserMapper">
    <select id="selectUser" resultType="com.jx.pojo.User">
        select * from mybatis.user
    </select>
</mapper>

10.编写测试类

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

import java.util.List;

public class UserMapperTest {
    @Test
    public  void test(){
        //获得SqlSession对象
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        //方式一：getMapper
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> userList = mapper.getUserList();

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

        //关闭SqlSession
        sqlSession.close();
    }
}

可能会出现问题：Maven静态资源过滤问题

解决方法：在build中配置resource

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