IDEA Mybatis入门

先要按照Person类建数据库，并插入数据

Person类 

package dao;

public class Person {
    private int id;
    private String name;
    private int age;

    public Person(){}

    public Person(int id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    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 int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

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

personMapper.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="dao.personMapper">
    <!-- 自定义返回结果集 -->

    <select id="queryPersonById" parameterType="int" resultType="dao.Person">
        select * from `user` where id = #{id}
    </select>
</mapper>

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>


    <!-- 配置mybatis运行环境 -->
    <environments default="development">
        <environment id="development">
            <!-- type="JDBC" 代表使用JDBC的提交和回滚来管理事务 -->
            <transactionManager type="JDBC"/>

            <!-- mybatis提供了3种数据源类型，分别是：POOLED,UNPOOLED,JNDI -->
            <!-- POOLED 表示支持JDBC数据源连接池 -->
            <!-- UNPOOLED 表示不支持数据源连接池 -->
            <!-- JNDI 表示支持外部数据源连接池 -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/sunwb?characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>


    <mappers>
        <!-- 映射文件方式1，一个一个的配置-->
        <mapper resource="dao/personMapper.xml"/>
        <!-- 映射文件方式2，自动扫描包内的Mapper接口与配置文件 -->
        <!--<package name="com.mybatis.demo"/>-->
    </mappers>

</configuration>

测试

package dao;
import java.io.IOException;
import java.io.Reader;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;


public class PersonTest {
    public static void main(String[] args) throws IOException {
        Reader reader = Resources.getResourceAsReader("dao/mybatis-config.xml");
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);
        SqlSession session= sessionFactory.openSession();
        String statement = "dao.personMapper.queryPersonById";
        Person person = session.selectOne(statement,1);
        System.out.println(person);
        session.close();
    }
}

输出：Person{id=1, name='lisi', age=20}