<settings>

        <setting name="cacheEnabled" value="true"/><!--开启，他也是默认值-->

        <!--<setting name="cacheEnabled" value="false"/>--><!--关闭-->

    </settings>

/*二级缓存*/

    @Test

    public void t4SecondCacheHasExist(){

        SqlSession session= MyBatisUtils.getSession();

        IDeptDAO mapper = session.getMapper(IDeptDAO.class);

        Dept depts = mapper.findDeptnoALLEmpsMoreSql();

        System.out.println(depts.getDeptName());

        session.close();

        System.out.println("===================我是高冷的分割线=====================");

        SqlSession session2= MyBatisUtils.getSession();

        IDeptDAO mapper2 = session2.getMapper(IDeptDAO.class);

        Dept depts2 = mapper2.findDeptnoALLEmpsMoreSql();

        System.out.println(depts2.getDeptName());

        session2.close();

    }

    <!--

        eviction:清理缓存策咯，默认值LRU,最近最少使用先清除

        flushInterval:刷新间隔，默认不设置，就是永久

        size：对象，默认1024

        readOnly：只读，默认false

     -->

    <!--二级缓存-->

    <cache eviction="FIFO" flushInterval="" size="" readOnly="true"/>

    <!--设置二级缓存单条sql失效-->

    <select id="findDeptnoALLEmpsMoreSql" resultMap="DeptMoreSqlMapper" useCache="false">

        SELECT deptNo,deptName FROM dept WHERE deptNo=#{deptNo}

    </select>

        <dependency>

            <groupId>net.sf.ehcache</groupId>

            <artifactId>ehcache</artifactId>

            <version>2.10.</version>

        </dependency>

        <!--MyBatis整合EhCache的包-->

        <dependency>

            <groupId>org.mybatis.caches</groupId>

            <artifactId>mybatis-ehcache</artifactId>

            <version>1.1.</version>

        </dependency>    

    <cache type="org.mybatis.caches.ehcache.EhcacheCache"></cache>

<ehcache>

    <!-- Sets the path to the directory where cache .data files are created.

         If the path is a Java System Property it is replaced by

         its value in the running VM.

         The following properties are translated:

         user.home - User's home directory

         user.dir - User's current working directory

         java.io.tmpdir - Default temp file path -->

    <diskStore path="java.io.tmpdir"/>

    <!--Default Cache configuration. These will applied to caches programmatically created through

        the CacheManager.

        The following attributes are required for defaultCache:

        maxInMemory       - Sets the maximum number of objects that will be created in memory

        eternal           - Sets whether elements are eternal. If eternal,  timeouts are ignored and the element

                            is never expired.

        timeToIdleSeconds - Sets the time to idle for an element before it expires. Is only used

                            if the element is not eternal. Idle time is now - last accessed time

        timeToLiveSeconds - Sets the time to live for an element before it expires. Is only used

                            if the element is not eternal. TTL is now - creation time

        overflowToDisk    - Sets whether elements can overflow to disk when the in-memory cache

                            has reached the maxInMemory limit.

        -->

    <defaultCache

        maxElementsInMemory=""

        eternal="false"

        timeToIdleSeconds=""

        timeToLiveSeconds=""

        overflowToDisk="true"

        />

    <!--Predefined caches.  Add your cache configuration settings here.

        If you do not have a configuration for your cache a WARNING will be issued when the

        CacheManager starts

        The following attributes are required for defaultCache:

        name              - Sets the name of the cache. This is used to identify the cache. It must be unique.

        maxInMemory       - Sets the maximum number of objects that will be created in memory

        eternal           - Sets whether elements are eternal. If eternal,  timeouts are ignored and the element

                            is never expired.

        timeToIdleSeconds - Sets the time to idle for an element before it expires. Is only used

                            if the element is not eternal. Idle time is now - last accessed time

        timeToLiveSeconds - Sets the time to live for an element before it expires. Is only used

                            if the element is not eternal. TTL is now - creation time

        overflowToDisk    - Sets whether elements can overflow to disk when the in-memory cache

                            has reached the maxInMemory limit.

        -->

    <!-- Sample cache named sampleCache1

        This cache contains a maximum in memory of  elements, and will expire

        an element if it is idle for more than  minutes and lives for more than

         minutes.

        If there are more than  elements it will overflow to the

        disk cache, which in this configuration will go to wherever java.io.tmp is

        defined on your system. On a standard Linux system this will be /tmp"

        -->

    <cache name="sampleCache1"

        maxElementsInMemory=""

        eternal="false"

        timeToIdleSeconds=""

        timeToLiveSeconds=""

        overflowToDisk="true"

        />

    <!-- Sample cache named sampleCache2

        This cache contains  elements. Elements will always be held in memory.

        They are not expired. -->

    <cache name="sampleCache2"

        maxElementsInMemory=""

        eternal="true"

        timeToIdleSeconds=""

        timeToLiveSeconds=""

        overflowToDisk="false"

        /> -->

    <!-- Place configuration for your caches following -->

</ehcache>