mybatis入门——mybatis的环境搭建

创建maven工程

直接选择next下一步

重命名

选择Finish

等待部署

添加依赖坐标

复制配置文件log4j.properties到src目录下

编写User实体类

package com.sunyan.domain;

import java.io.Serializable;
import java.util.Date;

public class User implements Serializable {

    private Integer id;
    private String username;
    private String address;
    private String sex;
    private Date birthday;

    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", address='" + address + '\'' +
                ", sex='" + sex + '\'' +
                ", birthday=" + birthday +
                '}';
    }
}

在resource目录下创建mybatis的主配置文件SqlMapConfig.xml

复制头部约束

<?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">

进行配置

<configuration>
    <!--配置环境-->
    <environments default="mysql">
        <!--配置mysql的环境-->
        <environment id="mysql">
            <!--配置事务-->
            <transactionManager type="JDBC"></transactionManager>
            <!--配置连接池-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <!--配置映射文件的位置-->
    <mappers>
        <mapper resource="com/sunyan/dao/UserDao.xml"></mapper>
    </mappers>

</configuration>

创建dao的接口

在com.sunyan.dao中创建接口UserDao

package com.sunyan.dao;

import com.sunyan.domain.User;

import java.util.List;

/**
 * 持久层接口
 */
public interface UserDao {
    /**
     * 查询所有用户
     * @return
     */
    List<User> findAll();
}

创建映射配置文件

在resource目录下创建文件

注意：对照包的结构，一级一级地创建文件夹

复制配置文件头部约束，并添加配置

<?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.sunyan.dao.UserDao">
    <!--查询所有-->
    <select id="findAll" resultType="com.sunyan.domain.User">
        select * from user;
    </select>
</mapper>

namesqpce：确定该方法在哪一个dao接口
id：哪一个方法
resultType：要封装到哪里去

编写测试类

创建

编写代码

package com.sunyan.test;

import com.sunyan.dao.UserDao;
import com.sunyan.domain.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.Test;

import java.io.InputStream;
import java.util.List;

/**
 * 测试mybatis的crud操作
 */
public class MybatisTest {

    /**
     * 测试查询所有
     */
    @Test
    public void testFindAll() throws Exception {
        //1.读取配置文件，生成字节输入流
        InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.获取SqlSessionFactory
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
        //3.获取SqlSession对象
        SqlSession sqlSession = factory.openSession();
        //4.获取dao的代理对象
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        //5.执行查询所有方法
        List<User> users = userDao.findAll();
        for (User user : users) {
            System.out.println(user);
        }
        //6.释放资源
        sqlSession.close();
        in.close();
    }
}

mybatis入门——mybatis的环境搭建

原文：https://www.cnblogs.com/sunyanblog/p/12380581.html