Mybatis ——基于注解的二级缓存

@CacheNamespace(blocking = true)//开启二级缓存 相当于在xml中写 useCache="true

 

package com.itheima.test;

import com.itheima.dao.IUserDao;
import com.itheima.domain.User;
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.Test;

import java.io.InputStream;

/**
 *二级缓存测试
 */
public class SecondLevelCatchTest {

    private InputStream in;
    private SqlSessionFactory factory;


    @Before
    public  void init()throws Exception{
        in = Resources.getResourceAsStream("SqlMapConfig.xml");
        factory = new SqlSessionFactoryBuilder().build(in);

    }

    @After
    public  void destroy()throws  Exception{

        in.close();
    }

    @Test
    public void testFindOne(){
        SqlSession session = factory.openSession();
        IUserDao userDao = session.getMapper(IUserDao.class);
        User user = userDao.findById(41);//第一次查询，将得到的数据写入二级缓存中
        System.out.println(user);

        session.close();//释放一级缓存

        SqlSession session1 = factory.openSession();//再次打开session
        IUserDao userDao1 = session1.getMapper(IUserDao.class);
        User user1 = userDao1.findById(41);//第二次不执行sql进行查询了，而是从二级缓存中直接取数据
        System.out.println(user1);


        session1.close();

    }
}