第一个Mybatis程序

• • 第一个Mybatis程序
  • • 搭建环境
    • • 搭建数据库
      • 创建项目
    • 导入Mybatis
    • 编写代码
    • 测试

搭建环境–>导入Mybatis–>编写代码–>测试

create database `mybatis06`;

use mybatis06;

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,'晋小','2122'),
(2,'晋大','2132'),
(3,'晋王','21452')

1、新建项目

2、删除src

3、创建模板

4、在父工程中导入依赖

 
    
        
        
            mysql
            mysql-connector-java
            5.1.46
        
        
        
            org.mybatis
            mybatis
            3.5.7
        
        
        
            junit
            junit
            3.8.1
        
	


 
        
            
                src/main/resources
                
                    ***.xml
                
                false
            
            
                src/main/java
                
                    ***.xml
                
                false
            
        

       

• 在resource中创建mybatis-config.xml

• 编写mybatis工具类

public class MybatisUtils {
    //提升作用域
    private static SqlSessionFactory sqlSessionFactory;
    static{
        try {
            //第一步：获取sqlSessionFactory
            String resource = "org/mybatis/example/mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
    //第二步：从sqlSessionFactory中获取sqlSession
    //SqlSession 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();
    }

}

• 实体类

package com.pojo;

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 + ''' +
                '}';
    }
}

• Dao接口

public interface UserDao {
    List getUserList();
}

• 接口实现类由之前的UserDaoImpl转变为一个Mapper配置文件 ( UserMapper.xml )

    
    
        select *
        from mybatis06.user;
    

public class UserDaoTest {

    @Test
    public void test(){
        //第一步：获得SqlSession对象
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        //执行SQL
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        List userList = mapper.getUserList();
        for (User user : userList) {
            System.out.println(user);
        }
        //关闭sqlSession
        
        
        sqlSession.close();
    }
}