mybatis之注解方式实现

* 使用mybatis举例，使用注解方式实现
* 不需要针对UserMapperI接口去编写具体的实现类代码，这个具体的实现类由MyBatis帮我们动态构建出来，我们只需要直接拿来使用即可。
* 1、导入jar包：mybatis和mysql-connector
* 2、mybatis配置文件：mybatis-config.xml，加载Mapper接口路径
* 3、编写JavaBean类：UserBean
* 4、编写执行sql接口
* 5、编写测试类进行测试

mybatis-config-zhujie.xml

<?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>
    <!--从外部配置文件导入jdbc信息-->
    <properties resource="jdbc.properties"></properties>

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>

    <!--指定映射资源文件-->
    <mappers>
        <mapper class="zhujie.UserMapperInterface"></mapper>

    </mappers>
</configuration>

UserMapperInterface.java

package zhujie;

import bean.UserSalary;
import first.UserBean;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import java.util.List;

/*
* 使用mybatis举例，使用注解方式实现
* 不需要针对UserMapperI接口去编写具体的实现类代码，这个具体的实现类由MyBatis帮我们动态构建出来，我们只需要直接拿来使用即可。
* 1、导入jar包：mybatis和mysql-connector
* 2、mybatis配置文件：mybatis-config.xml，加载Mapper接口路径
* 3、编写JavaBean类：UserBean
* 4、编写执行sql接口
* 5、编写测试类进行测试，自动实例化，调用方法
* */
public interface UserMapperInterface {

    //    UserBean
    @Select("select * from user where id = #{id}")
    public UserBean selectOneUser(int id);

    @Select("select * from user")
    public List<UserBean> selectAllUser();

    @Insert("insert into user (id, name, age) values (#{id} ,#{name}, #{age})")
    public int insertUser(UserBean userBean);

    @Update("update user set name=#{name} where id=#{id}")
    public int updateUser(UserBean userBean);

    @Delete("delete from user where id=#{id}")
    public int deleteById(int id);

    @Delete("delete from user where id=#{id}")
    public int deleteByUserBean(UserBean userBean);

    // 使用User和Salary表联合查询
    @Select("select u.id, u.name, u.age, s.salary from user u, salary s where u.name = s.name and u.name = #{name}")
    public UserSalary selectOneUserSalary(String name);

}

TestZhuJie.java

package zhujie;

import bean.UserSalary;
import first.UserBean;
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 org.junit.After;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/*
* 使用mybatis举例，使用注解方式实现
* 不需要针对UserMapperI接口去编写具体的实现类代码，这个具体的实现类由MyBatis帮我们动态构建出来，我们只需要直接拿来使用即可。
* 1、导入jar包：mybatis和mysql-connector
* 2、mybatis配置文件：mybatis-config.xml，加载Mapper接口路径
* 3、编写JavaBean类：UserBean
* 4、编写执行sql接口
* 5、编写测试类进行测试
* */
public class TestZhuJie {
    String resource = "mybatis-config-zhujie.xml";
    SqlSessionFactory sqlSessionFactory = null;
    SqlSession session = null;

    @Before
    public void before() {
//        System.out.println("Before");
        try {
            InputStream inputStream = Resources.getResourceAsStream(resource);
//            创建工厂
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//            创建session对象
            session = sqlSessionFactory.openSession();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @After
    public void close() {
        session.close();
//        System.out.println("After");
    }

    @Test
    public void testSelectOneUser() {
//        接口自动实例化
        UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
//        执行sql
        UserBean userBean = userMapperInterface.selectOneUser(1);
        System.out.println(userBean);
    }

//    批量查询
    @Test
    public void testSelectAllUser() {
//        接口自动实例化
        UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
//        执行sql
        List<UserBean> listUserBean = userMapperInterface.selectAllUser();
        System.out.println("记录个数：" + listUserBean.size());
        System.out.println(listUserBean);
    }

    @Ignore
    @Test
    public void testInsertUser() {
        UserBean userBean = new UserBean("CoCo2", "50");
        UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
        int n = userMapperInterface.insertUser(userBean);
//        提交
        session.commit();
        System.out.println("插入数据成功：" + userBean);
    }

    @Ignore
    @Test
    public void testUpdateUser() {
        UserBean userBean = new UserBean(2, "Tom44", "40");
        UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
        userMapperInterface.updateUser(userBean);
        session.commit();
        System.out.println("修改数据成功：" + userBean);
    }

    @Ignore
    @Test
    public void testDeleteUser() {
        UserBean userBean = new UserBean(15, "XXX", "40");
        UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
        int n = userMapperInterface.deleteByUserBean(userBean);
        session.commit();
        System.out.println("删除数据成功：" + userBean);
        System.out.println("操作成功记录数：" + n);
    }

    @Test
    public void testSelectOneUserSalary() {
//        接口自动实例化
        UserMapperInterface userMapperInterface = session.getMapper(UserMapperInterface.class);
//        执行sql
        UserSalary userSalary = userMapperInterface.selectOneUserSalary("Tom");
        System.out.println(userSalary);
    }

}