mybtis入门

1.编写持久化对象

public class User {
	private  String id;//用户编号
    private String username;//用户名
	private String password;//用户密码
    public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
}

2.编写数据协议层

public interface UserDao {
    public List<User> getAllUser();//得到所有的用户
}

3.编写数据层

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="dao.UserDao">
      <select id="getAllUser" resultType="User">
          select * from user_inf
      </select>
    </mapper>

4.编写工具类

public class SqlSessionFactorytest {
	//定义参数
	public static SqlSessionFactory sqlSessionFactory=null;
	//定义配置文件
	public static String resource="mybatis-config.xml";
	public static InputStream inputStream;
//构建SesseionFactory
	public static SqlSessionFactory getSqlSessionFactoryBuider() {
		try {
			//读取配置文件
			inputStream=Resources.getResourceAsStream(resource);
			System.out.println("配置文件加载成功！！");
			//SqlSessionFactoryBuilder通过输入流的相关配置得到sqlSessionFactory
		}catch(IOException e) {
			e.printStackTrace();
		}
		sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
		System.out.println("sqlSessionFactory创造成功！！");
		return sqlSessionFactory;

	}
}

这个工具主要是获得SqlSessionFactory

5.编写主类

public class test {
       public static void main(String[] args) {
        //有工具类获得SqlSessionFactory
	SqlSessionFactory sqlSessionFactory=SqlSessionFactorytest.getSqlSessionFactoryBuider();
	//由SqlSessionFactoty获得SqlSession
        SqlSession sqlSession=sqlSessionFactory.openSession();
        //获得Mapper接口
	UserDao userDao=sqlSession.getMapper(UserDao.class);
	List<User> user=userDao.getAllUser();
	for(int x=0;x<user.size();x++) {
		User u=user.get(x);
		System.out.println(u.getId());
		System.out.println(u.getUsername());
		System.out.println(u.getPassword());
	}
}
}