[大数据]Mybatis接口注解

1.创建一个接口：IUser，并在其中声明对应的操作方法

public interface IUser {
     @Select("select * from user where id= #{id}")
     public User getUserByID(int id);
}

2. 创建对应映射接口的SQL语句

<?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>
    <typeAliases>
        <typeAlias alias="User" type="com.mybatis.models.User" />
    </typeAliases>

    <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://127.0.0.1:3306/testdb" />
                <property name="username" value="root" />
                <property name="password" value="123456" />
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="com/mybatis/models/User.xml" />-->
    </mappers>
</configuration>

在包：com.mybatis.models 下创建一个User.java 类文件

package com.mybatis.models;

public class User {
    private int id;
    private String name;
    private String dept;
    private String phone;
    private String website;

    public String getWebsite() {
        return website;
    }
    public void setWebsite(String website) {
        this.website = website;
    }
    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 getDept() {
        return dept;
    }
    public void setDept(String dept) {
        this.dept = dept;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }

}

3.测试接口映射
在 src 这个目录下创建一个类：Main.java，用来测试整个配置和程序运行结果，有关 Main.java 的代码详细内容如下

import java.io.Reader;
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 com.mybatis.dao.IUser;
import com.mybatis.models.User;

public class Main {
    private static SqlSessionFactory sqlSessionFactory;
    private static Reader reader;
    static {
        try {
            reader = Resources.getResourceAsReader("config/Configure.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
            sqlSessionFactory.getConfiguration().addMapper(IUser.class);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static SqlSessionFactory getSession() {
        return sqlSessionFactory;
    }

    public static void main(String[] args) {
        SqlSession session = sqlSessionFactory.openSession();
        try {
            IUser iuser = session.getMapper(IUser.class);
            User user = iuser.getUserByID(1);
            System.out.println("名字："+user.getName());
            System.out.println("所属部门："+user.getDept());
            System.out.println("主页："+user.getWebsite());
        } finally {
            session.close();
        }
    }
}