mybatis入门篇（二）

1、数据准备

2、编写实体类

package com.forest.owl.entity;

import java.util.Date;

public class User {
    private Long id;
    private String userName;
    private String userPassword;
    private String userPhone;
    private String userEmail;
    private byte[] headImg;
    private Date createTime;
    private Date updateTime;

    public Long getId() {
        return id;
    }

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

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserPassword() {
        return userPassword;
    }

    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }

    public String getUserPhone() {
        return userPhone;
    }

    public void setUserPhone(String userPhone) {
        this.userPhone = userPhone;
    }

    public String getUserEmail() {
        return userEmail;
    }

    public void setUserEmail(String userEmail) {
        this.userEmail = userEmail;
    }

    public byte[] getHeadImg() {
        return headImg;
    }

    public void setHeadImg(byte[] headImg) {
        this.headImg = headImg;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public Date getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(Date updateTime) {
        this.updateTime = updateTime;
    }

}

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3、编写相对应的Mapper接口

package com.forest.owl.mapper;

import com.forest.owl.entity.User;

import java.util.List;

public interface UserMapper {

    User selectUserById(Long id);

    List<User> selectAllUser();

}

4、编写UserMapper.xml

在resources中加入文件夹com/forest/owl/mapper，在此文件夹中添加UserMapper文件

<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.forest.owl.mapper.UserMapper">
    <resultMap id="userMap" type="com.forest.owl.entity.User">
        <id property="id" column="id" />
        <result property="userName" column="user_name" />
        <result property="userPassword" column="user_password" />
        <result property="userPhone" column="user_phone" />
        <result property="userEmail" column="user_email" />
        <result property="headImg" column="head_img" jdbcType="BLOB" />
        <result property="createTime" column="create_time" jdbcType="TIMESTAMP" />
        <result property="updateTime" column="update_time" jdbcType="TIMESTAMP" />
    </resultMap>

    <select id="selectUserById" resultMap="userMap">
        SELECT * FROM user WHERE id=#{id}
    </select>

    <select id="selectAllUser" resultType="com.forest.owl.entity.User">
        SELECT id, user_name, user_password, user_phone, user_email, head_img, create_time, update_time
        FROM user
    </select>
</mapper>

5、修改mybatis-config.xml文件

<?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>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>

    <typeAliases>
        <package name="com.forest.owl.entity"/>
    </typeAliases>
    
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC">
                <property name="" value=""/>
            </transactionManager>
            <dataSource type="UNPOOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/forest?useSSL=false"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <package name="com.forest.owl.mapper"/>
    </mappers>
</configuration>

6、编写测试代码

package com.forest.owl;

import com.forest.owl.entity.User;
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 org.junit.BeforeClass;

import java.io.IOException;
import java.io.Reader;

public class BaseMapperTest {
    private static SqlSessionFactory sqlSessionFactory;

    @BeforeClass
    public static void init(){
        try {
            Reader reader = Resources.getResourceAsReader("mybatis.config.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public SqlSession getSqlSession(){
        SqlSession sqlSession = sqlSessionFactory.openSession();
        return sqlSession;
    }
}

package com.forest.owl;

import com.forest.owl.entity.User;
import com.forest.owl.mapper.UserMapper;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;

public class MapperTest extends BaseMapperTest{

    @Test
    public void UserMapperTest(){
        SqlSession sqlSession = getSqlSession();
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        User user = userMapper.selectUserById((long) 3);
        System.out.println(user.getUserName());

        List<User> userList = userMapper.selectAllUser();
        userList.stream().forEach(i -> System.out.println(i.getUserName()));
    }
}

mybatis入门篇（二）

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