mybatis---demo1--(缓存)----bai

News-mapper.xml 配置：

<?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">

<!-- 既是实体的映射文件。类似orm。同时又是dao的实现代码 -->

<mapper namespace="com.etc.dao.NewsDao">

<cache  readOnly="true" size="100000">   <!-- 配置缓存-->

</cache>

<!-- 配置实体和数据表的映射关系 -->

<resultMap type="News" id="NewsResult">

	<id column="id" property="id"/>  <!-- 主键 -->

	<result column="title" property="title"/>

	<result column="content" property="content"/>

</resultMap>

 <!-- 查询全部，实现findAll方法 -->

<select id="findAll" resultMap="NewsResult">

	select * from news

</select>

<!-- 精确查询 ,实现findbyid的方法-->

<select id="findById" parameterType="java.lang.Integer" resultType="News">

	select * from news where id=#{id}

</select>

<!-- 添加 -->

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

	insert into news (title,content) values(#{title},#{content})

</insert>

<!-- 修改-->

<update id="update" parameterType="News" >

	update news set title=#{title},content=#{content} where id=#{id}

</update>

<!-- 删除 -->

<delete id="delete" parameterType="java.lang.Integer">

	delete from news where id=#{id}

</delete>

</mapper>

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测试类：

package com.etc.test;

import java.util.List;

import org.apache.ibatis.session.SqlSession;

import org.junit.Test;

import com.etc.dao.NewsDao;

import com.etc.entity.News;

import com.etc.utils.MyBatisSessionFactory;

public class TestNewsDao {

	@Test

	public  void testLevel1()

	{

		// 1 获取连接

		SqlSession session = MyBatisSessionFactory.getSession();

		//2 执行查询

		News n1 = session.getMapper(NewsDao.class).findById(1);

		System.out.println(n1);

		session.clearCache();//删除全部的1级缓存

		MyBatisSessionFactory.closeSession();

		session = MyBatisSessionFactory.getSession();

		News n2 = session.getMapper(NewsDao.class).findById(1);

		System.out.println(n1==n2);

		//3 关闭

		MyBatisSessionFactory.closeSession();

	}

}

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