mybatis二級緩存的實現代碼

<?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>

<!-- 新增settings標簽-->
 <settings>
    <!-- 開啟二級緩存 -->
   <settring name="cacheEnabled" value="true"/>
 
 </settings>

 <environments default="development">
  <environment id="development">
   <transactionManager type="JDBC"/>
   <dataSource type="POOLED">
    <property name="driver" value="com.mysql.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/hkgoods"/>
    <property name="username" value="root"/>
    <property name="password" value="123456"/>
   </dataSource>
  </environment>
 </environments>
 <mappers>
  <mapper resource="mappers/GoodsInfoMapper.xml"/>
  <mapper resource="mappers/NationMapper.xml"/>
 </mappers>
</configuration>

<!-- 想要當前查詢支持二級緩存 需要在標簽 加入 useCache="true-->
 <select id="selAll" resultType="com.chen.GoodsInfo" useCache="true">
  select ID e_id,name e_name,image e_image from goods 
 </select>

public class Start2 {

  public static void main(String[] args) throws IOException {
    
    String resource = "mybatis-conf.xml";
    InputStream inputStream = Resources.getResourceAsStream(resource);
    //創建SqlSessionFactory
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    //true表示自動提交。否則需要使用commit方法才會提交。默認是false
    SqlSession session = sqlSessionFactory.openSession();
    
    //拿到接口的代理對象
    GoodsDao2 dao=session.getMapper(GoodsDao2.class);
    //拿到了dao這個對象接下來就可以創建sql語句了;（直接調用接口方法）
    long s1 = System.currentTimeMillis();
    List list = dao.selAll();
    System.out.println(list);
    long e1 =System.currentTimeMillis();
    System.out.println("第一次查詢時間:"+(e1-s1));
    
    //再做一次重復查詢，測試下執行時間
    SqlSession session2 = sqlSessionFactory.openSession(); 
    //拿到接口的代理對象
    GoodsDao2 dao2=session2.getMapper(GoodsDao2.class);
    long s2 = System.currentTimeMillis();
    List list2 = dao2.selAll();
    System.out.println(list2);
    long e2 =System.currentTimeMillis();
    System.out.println("第一次查詢時間:"+(e2-s2));
  
    //如果上面不設置自動提交表單，那么就需要commit方法
    session.commit();
  }

}

public class Start2 {

  public static void main(String[] args) throws IOException {
    
    String resource = "mybatis-conf.xml";
    InputStream inputStream = Resources.getResourceAsStream(resource);
    //創建SqlSessionFactory
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    //true表示自動提交。否則需要使用commit方法才會提交。默認是false
    SqlSession session = sqlSessionFactory.openSession();
    
    //拿到接口的代理對象
    GoodsDao2 dao=session.getMapper(GoodsDao2.class);
    //拿到了dao這個對象接下來就可以創建sql語句了;（直接調用接口方法）
    long s1 = System.currentTimeMillis();
    List list = dao.selAll();
    System.out.println(list);
    long e1 =System.currentTimeMillis();
    System.out.println("第一次查詢時間:"+(e1-s1));
    
    
    //在新的SqlSession對象，使用二級緩存中的數據的時候，需要先將前面的SqlSession對象關閉,數據才會進入二級緩存
    session.close();
    //再做一次重復查詢，測試下執行時間
    SqlSession session2 = sqlSessionFactory.openSession(); 
    //拿到接口的代理對象
    GoodsDao2 dao2=session2.getMapper(GoodsDao2.class);
    long s2 = System.currentTimeMillis();
    List list2 = dao2.selAll();
    System.out.println(list2);
    long e2 =System.currentTimeMillis();
    System.out.println("第一次查詢時間:"+(e2-s2));
    
\
    //如果上面不設置自動提交表單，那么就需要commit方法
    session.commit();
  }

}