1.通过maven导入关于mybatis的jar包

可以通过阿里云的maven库直接下载相关jar包

<dependencies>
 <dependency>
 <groupId>org.mybatis</groupId>
 <artifactId>mybatis</artifactId>
 <version>3.4.5</version>
 </dependency>
<dependency>
 <groupId>MySQL</groupId>
 <artifactId>mysql-connector-Java</artifactId>
 <version>5.1.38</version>
</dependency>
</dependencies>

2.编写mybatis的配置文件

<?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>

<environments default="development"> 
 <environment id="development"> 
 <transactionManager type="JDBC" /> 
 <!-- 配置数据库 -->
 <dataSource type="POOLED"> 
 <property name="driver" value="com.mysql.jdbc.Driver" /> 
 <property name="url" value="jdbc:mysql://localhost:3306/my_schema?useSSL=true" /> 
 <property name="username" value="root" /> 
 <property name="password" value="" /> 
 </dataSource> 
 </environment> 
</environments> 
<!-- 映射文件 -->
<mappers> 
 <mapper resource="UserMapper.xml" /> 
</mappers> 
</configuration>

3.编写映射文件UserMapper.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="userMapper"> 
<select id="selectUser" resultType="entity.User"> 
 select * from user 
</select> 
</mapper>

4.写出实体类User,很平常的类,就不在过多解释.

public class User {
private String username;
private String email;
private String password;
private String create_time;
public String getUsername() {
 return username;
}
public void setUsername(String username) {
 this.username = username;
}
public String getEmail() {
 return email;
}
public void setEmail(String email) {
 this.email = email;
}
public String getPassword() {
 return password;
}
public void setPassword(String password) {
 this.password = password;
}
public String getCreate_time() {
 return create_time;
}
public void setCreate_time(String create_time) {
 this.create_time = create_time;
}
@Override
public String toString() {
 return "User [username=" + username + ", email=" + email + ", password=" + password + ", create_time="
 + create_time + "]";
}
public User(String username, String email, String password, String create_time) {
 super();
 this.username = username;
 this.email = email;
 this.password = password;
 this.create_time = create_time;
}
public User() {
 super();
}

}

5.在写一个类MybatisSamples,里面包含main方法,进行测试.

具体代码如下

public static void main(String[] args) {
 String resource = "mybatis-config.xml";
 SqlSession session = null;
 try {
 InputStream is = Resources.getResourceAsStream(resource);
 //获取一个session工厂
 SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
 //通过工厂获取session
 session = sqlSessionFactory.openSession();
 //根据映射文件中select标签的id获取集合
 List<User> list = session.selectList("userMapper.selectUser");
 for(User user: list) {
 System.out.println(user);
 
 }
 } catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }finally {
 //注意关闭session!!!
 session.close();
 }
 
}

执行结果如下:

附:
包结构

数据库结构

总结:想入门mybatis最重要的两步,第一是写配置文件,配置数据库和mapper,第二步是写好mapper和实体类,mapper中写sql语句,然后可以就可以通过mybatis把表中的数据映射成为一个对象了。