Mybatis（2）第一个程序

一，搭建环境

CREATE TABLE `user`
(
id INT(20) NOT NULL PRIMARY KEY,
name VARCHAR(30) DEFAULT NULL,
pwd VARCHAR(30) DEFAULT NULL
)ENGINE=INNODB DEFAULT CHARSET=utf8;

INSERT INTO `user`(`id`,`name`,`pwd`)VALUES
(1,'陈','123456'),
(2,'宏','123465'),
(3,'煦','123465')

<!--    父工程-->
<!--    导入依赖-->

<!--    mysql驱动-->
<!--    mybatis-->
<!--    junit-->
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.23</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
    </dependencies>


链接数据库时区设置

 

 

二，创建模块
1，编写mybatis的核心配置文件

<?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>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.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis1?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="hmc3344djl"/>
            </dataSource>
        </environment>
    </environments>
</configuration>

2，编写mybatis工具类

package com.xu.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.InputStream;
import java.io.IOException;

//sqlSessionFactory --> sqlSession
public class MybatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            //使用Mybatis第一步：获取sqlSessionFactroy对象
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    //既然有了SqlSessionFactory,就可以从中获得SqlSession的实例。
    //SqlSeesion完全包含了面向数据库执行sql命令所需的所有方法。
    public static SqlSession getSqlSession() {
        return sqlSessionFactory.openSession();
    }
}

三，编写代码
实体类User.java
package com.xu.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

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;
}
}

Dao接口UserDao
public interface UserDao {
public List getUserLIst();
}

接口实现类，由原来的UserDaolmpl转变味一个Mapper配置文件
!!!!!

select * from USER mybaits1.user

四，测试
注意点：
MAVEN中加入！！！！！！！！



src/main/resources

/*.properties
/.xml

true


src.mian/java

**/.properties
**/*.xml

true

junit测试
package com.xu.dao;

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

import java.util.List;

public class UserDaoTest {
@Test
public void test(){

//第一步获得SqlSession对象
SqlSession sqlSession = MybatisUtils.getSqlSession();
//执行SQL
//方式一：getMapper
UserDao mapper = sqlSession.getMapper(UserDao.class);
List userList = mapper.getUserList();

for (User user : userList) {
System.out.println(user);
}
//关闭sqlSession
sqlSession.close();
}
}