<?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">

<!-- 如果我要调用mapper文件，就去拿到namespace+id(方法名)的名字就可以访问 -->

<mapper namespace="cn.bdqn.dao.UserMapper">

    <!-- id要唯一的，一般是下拉类的方法名 -->

    <!-- 返回的是什么类型int -->

    <select id="count" resultType="int">

        select count(1) from user

    </select>

    <!-- 增加 -->

    <insert id="add" parameterType="User">

        insert into user(userCode,userName,userPassword)

            values (#{userCode},#{userName},#{userPassword})

    </insert>

    <!-- 修改 -->

    <update id="update" parameterType="User">

        update user set userCode=#{userCode},userName=#{userName},

        userPassword=#{userPassword} where id=#{id}

    </update>

    <!-- 删除 -->

    <delete id="delete" parameterType="User">

        delete from user where id=#{id}

    </delete>

    <!-- 查询 -->

    <select id="getUserList" resultType="User">

        select * from user

    </select>

</mapper>

<?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">

<!-- 通过这个配置文件完成mybatis与数据库的连接 -->

<configuration>

    <!-- 引入 jdbc.properties 文件-->

    <properties resource="jdbc.properties"/>

    <!-- alias别名 -->

    <typeAliases>

        <!-- <typeAlias type="cn.bdqn.pojo.User" alias="User"/> -->

        <!-- 用这个比较方便，不用一个一个写。包下的就是他的类名 -->

        <package name="cn.bdqn.pojo"/>

    </typeAliases>

    <environments default="development">

        <environment id="development">

            <!--配置事务管理，采用JDBC的事务管理  -->

            <transactionManager type="JDBC"></transactionManager>

            <!-- POOLED:mybatis自带的数据源，JNDI:基于tomcat的数据源 -->

            <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>

    <!-- 将mapper文件加入到配置文件中  将来mapper文件很多所以是mappers -->

    <mappers>

        <mapper resource="cn/bdqn/dao/UserMapper.xml"/>

    </mappers>

</configuration>

public class MyBatisUtil {

    private static SqlSessionFactory factory;

    /**

     * 一般情况下,如果有些代码必须在项目启动的时候就执行的时候,需要使用静态代码块,这种代码是主动执行的;

     * 需要在项目启动的时候就初始化,在不创建对象的情况下,其他程序来调用的时候,需要使用静态方法,这种代码是被动执行的.

     * 静态方法在类加载的时候 就已经加载 可以用类名直接调用

     */

    static{//在静态代码块下，factory只会被创建一次

        System.out.println("static factory===============");

        try {

            InputStream is = Resources.getResourceAsStream("mybatis-config.xml");

            factory = new SqlSessionFactoryBuilder().build(is);

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

    //创建sqlSession

    public static SqlSession createSqlSession(){

        return factory.openSession();

    }

    //关闭资源

    public static void closeSqlSession(SqlSession sqlSession){

        if(null != sqlSession)

                sqlSession.close();

    }

}

public class UserDaoTest {

    private Logger logger = Logger.getLogger(UserDaoTest.class);

    //count

    @Test

    public void countTest() {

        SqlSession sqlSession = null;

        int count = 0;

        try {

            sqlSession = MyBatisUtil.createSqlSession();

            count = sqlSession.selectOne("cn.bdqn.dao.UserMapper.count");

            logger.debug("count==="+count);

        } catch (Exception e) {

            // TODO: handle exception

            sqlSession.rollback();

        }finally{

            MyBatisUtil.closeSqlSession(sqlSession);

        }

    }

    //add

    @Test

    public void addTest(){

        SqlSession sqlSession = null;

        try {

            User user = new User();

            user.setUserCode("aaaa");

            user.setUserName("bbbbb");

            sqlSession = MyBatisUtil.createSqlSession();

            sqlSession.insert("cn.bdqn.dao.UserMapper.add",user);

            sqlSession.commit();

        } catch (Exception e) {

            // TODO: handle exception

            e.printStackTrace();

            sqlSession.rollback();

        }finally{

            MyBatisUtil.closeSqlSession(sqlSession);

        }

    }

    //修改

    @Test

    public void updateTest(){

        SqlSession sqlSession = null;

        try {

            User user = new User();

            user.setId(12);

            user.setUserCode("改1111");

            user.setUserName("改2222");

            sqlSession = MyBatisUtil.createSqlSession();

            sqlSession.update("cn.bdqn.dao.UserMapper.update",user);

            sqlSession.commit();

        } catch (Exception e) {

            // TODO: handle exception

            e.printStackTrace();

            sqlSession.rollback();

        }finally{

            MyBatisUtil.closeSqlSession(sqlSession);

        }

    }

    //删除

    @Test

    public void deleteTest(){

        SqlSession sqlSession = null;

        try {

            User user = new User();

            user.setId(12);

            sqlSession = MyBatisUtil.createSqlSession();

            sqlSession.delete("cn.bdqn.dao.UserMapper.delete",user);

            sqlSession.commit();

        } catch (Exception e) {

            // TODO: handle exception

            e.printStackTrace();

            sqlSession.rollback();

        }finally{

            MyBatisUtil.closeSqlSession(sqlSession);

        }

    }

}

//查询

    @Test

    public void getUserListTest(){

        SqlSession sqlSession = null;

        try {

            List<User> userList = new ArrayList<User>();

            sqlSession = MyBatisUtil.createSqlSession();

            userList = sqlSession.selectList("cn.bdqn.dao.UserMapper.getUserList");

            for(User user:userList){

                logger.debug("user的id==="+user.getId());

            }

        } catch (Exception e) {

            // TODO: handle exception

            e.printStackTrace();

            sqlSession.rollback();

        }finally{

            MyBatisUtil.closeSqlSession(sqlSession);

        }

    }