Mybatis简易入门

一、导包

导入需要的jar包

二、新建实体类User

public class User {
	int id;
	String name;
	int age;
	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 int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
	}
	
}

三、新建类的映射文件，和User.java在同一个路径下

<?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="top.mzp.test.User">
   
     <select id="findUserById" parameterType="int"  resultType="top.mzp.test.User">
          select * from tb_test where id=#{id} 
     </select>
 </mapper>

四、新建Mybatis框架配置文件，在src路径下

<?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" />
              <dataSource type="POOLED">
                  <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/db_test" />
                 <property name="username" value="root" />
                 <property name="password" value="root" />
             </dataSource>
         </environment>
     </environments>
     
     <mappers>
         <mapper resource="top/mzp/test/User.xml"/>
     </mappers>
     
</configuration>

五、数据库配置

 在数据库命令行执行source  XXX.sql即可；

CREATE DATABASE IF NOT EXISTS db_test DEFAULT CHARSET utf8 COLLATE utf8_general_ci;
use db_test;
create table if not exists `tb_test`(
		`id` int unsigned auto_increment,
		`name`  varchar(100) not null,
		`age` int  not null,
		primary key ( `id` )
	)engine=InnoDB default charset=utf8;
	
insert into tb_test(name,age) values("James",1);
insert into tb_test(name,age) values("Allen",2);
insert into tb_test(name,age) values("Kobe",3);
insert into tb_test(name,age) values("Oneal",4);
insert into tb_test(name,age) values("Duncan",5);
insert into tb_test(name,age) values("Parker",6);
insert into tb_test(name,age) values("Wade",7);
insert into tb_test(name,age) values("Jack",8);

六、新建测试类测试

public class TestDemo1 {
    public static void main(String[] args) throws IOException {
      			//mybatis配置文件
    			String resource = "./conf.xml";
    			InputStream inputStream = Resources.getResourceAsStream(resource);
    			//创建会话工厂,传入配置文件信息
    			SqlSessionFactory sqlSessionFactory =
    					new SqlSessionFactoryBuilder().build(inputStream);
    			
    			//通过工厂得到SqlSession
    			SqlSession sqlSession  = sqlSessionFactory.openSession();
    			
    			//通过session操作数据库:第一个参数是id，第二个是parameterType参数
    			User user = sqlSession.selectOne("findUserById",1 );
    			
    			System.out.println("查询：" +  user );
    			
    			sqlSession.commit();
    			sqlSession.close();
    		}
}

七、输出结果

查询：User [id=1, name=James, age=1]