1、 项目目录
采用建立maven的一个普通java类来测试mybatis。
2、首先先看dao层的IUserDao
该层是持久层。里面有一个接口,用于查询存在一些查询的方法。
package com.mybatis.dao;
import com.mybatis.domain.User;
import java.util.List;
public interface IUserDao {
List<User> findAll();
}
3、再看domain层的User
这里面是一个类,这个类用于存放与数据库表对应的属性,也就是咱们说的ORM ,对象关系映射
package com.mybatis.domain;
import java.io.Serializable;
import java.util.Date;
public class User implements Serializable {
private Integer id;
private String username;
private Date birthday;
private String sex;
private String address;
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 Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", birthday=" + birthday +
", sex='" + sex + '\'' +
", address='" + address + '\'' +
'}';
}
}
4、接着看resources层的SqlMapConfig.xml
这里是配置整个数据库的信息
<?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">
<!--mybatis主配置文件-->
<configuration>
<!--配置环境-->
<environments default="mysql">
<!-- 配置mysql环境-->
<environment id="mysql">
<!-- 配置事务类型-->
<transactionManager type="JDBC"></transactionManager>
<!-- 配置数据源(连接池)-->
<dataSource type="POOLED">
<!-- 配置数据库的基本信息-->
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=GMT"/>
<property name="username" value="root"/>
<property name="password" value="111111"/>
</dataSource>
</environment>
</environments>
<!-- 指定映射配置文件的位置,映射配置文件指的是每一个dao独立的配置文件-->
<mappers>
<mapper resource="com/mybatis/dao/IUserDao.xml"/>
</mappers>
</configuration>
IUserDao.xml是具体配置哪个接口的配置文件
<?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.mybatis.dao.IUserDao">
<select id="findAll" resultType="com.mybatis.domain.User">
select * from users
</select>
</mapper>
5、测试类
package com.mybatis.test;
import com.mybatis.dao.IUserDao;
import com.mybatis.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 java.io.InputStream;
import java.util.List;
public class MybatisTest {
public static void main(String[] args)throws Exception {
// 1、读取配置文件
InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
// 2、创建SqlSessionFactory工厂
SqlSessionFactoryBuilder factoryBuilder = new SqlSessionFactoryBuilder();
SqlSessionFactory factory = factoryBuilder.build(in);
// 3、使用工厂生产SqlSession对象
SqlSession session = factory.openSession();
// 4、使用SqlSession创建Dao接口的代理对象
IUserDao userDao = session.getMapper(IUserDao.class);
// 5、使用代理对象执行方法
List<User> users = userDao.findAll();
for (User user:users){
System.out.println(user);
}
// 6、释放资源
session.close();
}
}