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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